Vitamin D: The Sunshine Vitamin
What is vitamin D?
There are 13 vitamins humans need for growth and development and to maintain good health. The human body can not make these essential bio-molecules. They must be supplied in the diet or by bacteria in the intestine, except for vitamin D. Vitamin D is a fat-soluble “vitamin” that is naturally present in very few foods, added to others (milk), and available as a dietary supplement. Since vitamin D is fat-soluble, it can be stored in the body as reserves, whereas water-soluble vitamins are regularly discarded when in excess.
Technically, Vitamin D is not actually a vitamin. It was misnamed back when it was discovered in the 1930’s. People often mistakenly call it a hormone but it is not a hormone. It is a pre-hormone, meaning it can be converted into a hormone. However, some of the cholecalciferol will also be turned into calcitriol, which is type of steroid hormone known as a secosteroid.
It is the trigger of a steroid-hormone system that starts in the skin and provides key biological functions vital to one’s health and well-being. It regulates cells by activating genes that control cell growth and programmed cell death (apoptosis), and expresses mediators that regulate the immune system and organs throughout the body. Receptors in the immune system, pancreas, heart-cardiovascular, muscle and brain systems in the body generate biological responses to vitamin D. It prevents and fights against many degenerative diseases as well as infectious diseases. It also releases neurotransmitters that influence one’s mental state. Its primitive functions of being able to turn certain genes on and off is a characteristic that is unique among “vitamins.”
If one is unable to supply their body with enough natural vitamin D3 from sunlight, then supplements are a good alternative. Although in the natural state, vitamin D does not enter the body orally.
Non-prescription vitamin D supplements are available in the United States as either Ergocalciferol (D2) or Cholecalciferol (D3). Both are referred to as vitamin D although they are different in their origins, metabolism, and potential toxicity.
Ergocalciferol (Vitamin D2) is derived from radiating fungus. It is not the naturally occurring vitamin D for humans. Fungus contains fat-like substances called sterols which are commercially irradiated to form ergocalciferol. As is it derived from plants, and not animals, ergocalciferol is considered Kosher. A doctor can prescribe 50,000 IU of ergocalciferol with brand names Drisdol and Calciferol. Vitamin D2 does not exist in the body in detectable quantities. Only in tiny quantities in plants and as such is not natural to be in the human body. You can not get any appreciable vitamin D2 by eating vegetables. Ergocalciferol is metabolized to various substances in the body, some of which are not normally present in humans, although these metabolites have never been shown to be dangerous. There is some evidence that ergocalciferol is more toxic in overdose, yet it is only half as potent as the naturally occurring vitamin D3. The human body also metabolizes ergocalciferol more quickly than cholecalciferol. But vitamin D binding proteins have a weaker affinity for the vitamin D2 metabolites than the vitamin D3 metabolites. Vitamin D2 is only 10–30% as effective in raising 25-hydroxyvitamin D blood levels compared to vitamin D3, leading the authors of a recent study to conclude, “Vitamin D2 should not be regarded as a nutrient suitable for supplementation or fortification.” Ergocalciferol is a synthetic analogue of cholecalciferol. Most of the available current toxicity data relates to vitamin D3, not vitamin D2.
To understand what the vitamin D system is one must understand the different forms of vitamin D3, mainly Cholecalciferol (Vitamin D3), Calcidiol and Calcitriol, which are all known as vitamin D. The current system of naming vitamin D is very confusing, as anything with vitamin D activity is often called “vitamin D.” This is like calling anything with corticosteroid activity, “cortisol,” or anything with androgen activity, “testosterone.” It is not only confusing, it makes no sense.
The body turns vitamin D (cholecalciferol) into two very important hormones, calcidiol (also sometimes called calcifediol with the brand names of Calderol and Dedrogyl, and dihydrotachysterol, brand name DHT Intensol) and calcitriol (brand names are Rocaltrol and Calcijex when injected). These two hormones are naturally occurring products of cholecalciferol metabolism and are extremely potent and only available as prescription medications. They are also sometimes called vitamin D. This borders on the ridiculous as it would be like calling both testosterone and estrogen “cholesterol,” as both are made from cholesterol. However, cholesterol, estrogen, and testosterone are very different molecules with very different functions. Likewise, cholecalciferol, calcidiol, and calcitriol are different molecules with different functions.
Furthermore, a number of compounds are based on variations of one of the naturally occurring vitamin D metabolites, usually calcitriol, and these are called vitamin D analogues. They are frequently used in chronic renal disease when the kidney has lost the ability to make calcitriol. The best known are doxercalciferol (taken orally with a brand name of Hectorol) and paricalcitol (intravenous with the brand name Zemplar).
The important thing to know: cholecalciferol (D3) is the vitamin D to take. Do not let your doctor give you any prescription medication for vitamin D. The only exception to this is ergocalciferol. Although with ergocalciferol you must remember you are taking a drug—not a vitamin—that does not normally occur in the human body.
Cholecalciferol (Vitamin D3) (pronounced koh·luh·kal·sif·uh·rawl)
Cholecalciferol is the naturally occurring form of vitamin D in humans and from here on, “vitamin D” refers to cholecalciferol. It is the substance made in large quantities when sunlight strikes your bare skin. The high rate of natural production of vitamin D3 cholecalciferol in the skin is the single most important fact every person should know about vitamin D. A fact that has profound implications for the natural human condition.
It can also be taken as a supplement. Cholecalciferol is vitamin D, all other compounds are either metabolic products or chemical modifications.
Cholecalciferol is manufactured from the fat of lambs wool by purifying the fat and extracting the cholecalciferol. It is quite potent as vitamin D is active in tiny quantities. One capsule at 1,000 IU is equivalent to 0.025 mg—only 0.000025 of a gram.
Potency just means the dose necessary for a response. The lower the dose, the greater the potency. For example, you might take two Tylenol tablets (1,000 mg) to relieve a headache. Current studies indicate one needs about 4,000 units of cholecalciferol a day to meet the body’s need for vitamin D. 4,000 units of cholecalciferol is equal to 100 micrograms, or 0.1 milligrams. So the 1,000 milligrams of Tylenol needed to help your headache is 10,000 times the 0.1 milligrams of cholecalciferol needed to help your body. Therefore, cholecalciferol is 10,000 times more potent than Tylenol.
This potency is one of the reasons vitamin D has a reputation as being toxic. Very few other vitamins and supplements, or even medications, are effective in microgram quantities.
Calcidiol (25(OH)D3 or 25D3)
Calcidiol (25-Hydroxyvitamin D) is a prehormone in your blood that is directly made from Cholecalciferol. Calcidiol is now thought by some scientists to have steroid hormone properties. It certainly helps maintain blood calcium levels. But calcidiol’s main importance is that it is the storage form of vitamin D. It is what fills your vitamin D storage tanks. When being tested for vitamin D deficiency, Calcidiol is the blood test that should be drawn. When someone refers to vitamin D levels, they are usually referring to calcidiol levels. The doctors and labs know the test as a 25-hydroxyvitamin D test (25(OH)D3) .
Calcitriol (1,25(OH)2D3 or 1,25D3)
Calcitriol (1,25-dihydroxyvitamin D) is made from Calcidiol in the kidneys and in tissues and is sometimes referred to as the active form of vitamin D. It is the most potent steroid hormone derived from cholecalciferol. In fact, it is the most potent steroid hormone in the human body with antimicrobial and anti-cancer properties. Remember how cholecalciferol is 10,000 times more potent than Tylenol? Well calcitriol is 10,000,000,000 (10 billion) times more potent than Tylenol. It is active in picogram quantities (1/1,000,000,000,000 of a gram).
Steroid hormones are simply any molecule in the body that is made from cholesterol that also acts to turn genes on and off. Calcitriol can turn genes on and off depending on whether the body is producing too much of a certain protein or not enough of it: it varies with diseases. Calcitriol targets over 2000 genes (@10% of the entire human genome) in the human body. That means that 1/10th of your genetic composition is waiting to be told what to do by vitamin D. Vitamin D is the only messenger that can trigger these genes to activate. This is important because that means that there are over 2,000 mechanisms of actions of calcitriol. It is essential for a wide range of your body’s functions.
It also up-regulates the production of over 200 naturally occurring antimicrobial peptides called cathelicidins that kill bacteria and viruses and any micro-organism with a cell wall without antibiotic resistance or side effects. Antimicrobial peptides are part of the innate immune response and are present in all classes of life. These peptides are potent broad spectrum antibiotics that have been demonstrated to kill bacteria (including strains that are resistant to conventional antibiotics), mycobacteria, enveloped viruses, fungi and even transformed or cancerous cells. Unlike the majority of conventional antibiotics it appears as though antimicrobial peptides may also have the ability to enhance immunity by functioning as immunomodulators. Immunomodulators either stimulate or suppress the immune responses. Vitamin D plays a role in the clearance of infection, controls cytokine production (inflammation) and helps healing. It is safe for use in infants, children and adults of all ages as well as pregnant and nursing women. Scientists and researchers have been looking for a long time for ways to genetically upregulate the production of these peptides. And just in the last few years, Professor John White at McGill University and others discovered that vitamin D is very effective at increasing the production of these peptides that fight off infections and disease.
Calcitriol helps the body fight against and prevent a variety of cancers as well as heart attacks, stroke, hypertension, autoimmune diseases, diabetes, depression, chronic pain, osteoarthritis, bone diseases like osteoporosis, muscle weakness, muscle wasting, birth defects, periodontal disease, obesity, inflammation, influenza and other infectious diseases and more. It is difficult to find a disease where vitamin D deficiency has not been mentioned as a possible factor, especially among infectious diseases.
Calcitriol levels should not be used to determine if you are deficient in vitamin D. Unfortunately, about 20% of United States doctors order the wrong test. They order a 1,25-dihydroxy-vitamin D test, thinking that by measuring the most potent steroid in the human body, calcitriol, they are getting useful information. They are not. 1,25-dihydroxy-vitamin D is an adaptive hormone; it goes up and down with calcium intake. So these doctors see the 1,25-dihydroxy-vitamin D is normal or high and tell their patients that they are ok when really, they are vitamin D deficient-advice that may prove fatal. Furthermore, most doctors who see a 25(OH)D of 30 ng/ml (75 nmol/L) will tell you that level is fine when it is not—that is, few doctors know how to correctly interpret the test results.
How is Vitamin D Produced and Processed in your body?
Cholecalciferol is formed in the skin when sunlight (ultra-violet B (UVB)) rays hit bare skin. After it is made in the skin or taken orally, it is transported to the liver and metabolized into calcidiol. Then the calcidiol takes one of two paths.
The first and essential path is to the kidneys where it is turned into calcitriol. Calcitriol made in the kidneys circulates in the blood to maintain your blood calcium levels. Some people with kidney disease may not be able to produce calcitriol. Calcium is vital to the function of the cells in the body. And without enough calcitriol, blood calcium levels will fall and illnesses will set in.
The second pathway is to the tissues. All of the health benefits of vitamin D discovered in the last 10 years are from vitamin D going down the second pathway, one that leads directly to the cells. That is, if your storage tank is full and the kidneys have enough calcidiol to maintain serum calcium. This second pathway is only now being fully understood and is the cause of much hope concerning cancer. These are the autocrine (inside cell) and paracrine (around the cell) functions of the vitamin D system. When your vitamin D reserves are not full, most of your calcidiol goes to your kidneys to maintain calcium levels in the blood. And as a result, very little or no calcidiol gets to your tissues to produce tissue calcitriol. But when your tanks are full, the tissue calcidiol goes to the many cells in the body that are able to make their own calcitriol to fight cancer. The more calcidiol the cells get, the more calcitriol they make. The step is not rate-limited by its product (calcitriol) and is thus uncontrolled. No other steroid hormone system in the body works this way. The manufacture of calcitriol in the tissues is unique.
This is one of the most important facts about vitamin D. Other steroids limit their own production by inhibiting the very chemical reactions that make them. When a steroid is in adequate supply, that specific steroid hormone production shuts down. This is called negative feedback. This occurs with all other steroids somewhere in the metabolic process. If it didn’t the body would not be able to maintain steroid hormone levels. It does not occur with calcitriol. Throughout the entire range of normal calcidiol levels, tissue calcitriol levels continue to increase.
This is a crucial piece of information because it has profound implications for the normal state of human affairs. Just as modern humans have been living and dying with low levels of calcidiol in their blood, their tissues have been living and dying with historically low levels of calcitriol. And calcitriol is the most potent steroid hormone in the body that turns genes on and off at an astonishingly high rate. The same genes that are either making proteins that are essential to fighting diseases like cancer, or genes that are making proteins that are promoting diseases like cancer.
So what limits the amount of tissue cholecalciferol? One thing that helps is catabolism, or breakdown. The more you make, the more is metabolized and excreted through bile. But that does not prevent too much from being produced in the first place. One possible way to limit the amount of calcitriol in your tissues would be to lower the amount of calcitriol in the blood. So in the natural state, the rate-limiting step for the production of calcitriol in the blood is your skin. As in how much you go into the sun. The skin has a built-in mechanism to prevent vitamin D toxicity. Once you make about 20,000 IU, the same UVB rays that created cholecalciferol begins to degrade it. Once you get a tan, even less vitamin D is made. Humans have a defense system in their skin to prevent vitamin D toxicity. What affects your vitamin D levels is how often you go out in the sun or how much vitamin D you take as a supplement. This makes cholecalciferol (D3) unique.
What does Vitamin D need to Help it Work Efficiently?
The nutrients that allow vitamin D to work at optimum capacity (Calcium, Magnesium) happen to be on the list of the top 10 nutritional deficiencies in America, along with vitamin D.
Calcium is one of the most important and abundant minerals in the human body. The average body contains about three pounds of calcium in our bones and our teeth, and some additional calcium is found in body tissues and in the blood system. Maintaining a balanced blood calcium level is vital for life, especially for cardiac function. Calcium plays a very important role in the prevention of osteoporosis in people 50 years of age and older. Magnesium is a very important macromineral that aids in calcium absorption. Vitamin D is needed for calcium and phosphorous to be absorbed from the digestive tract and helps maintain normal blood calcium levels.
Vitamin D, calcium and magnesium are essential for good health. They help us build and maintain healthy bones and teeth. They ensure that our muscles, including the heart muscle, contract and relax properly. They promote the smooth functioning of the nervous system. Without the help of calcium, our blood would not clot and we could not stop bleeding after a cut or injury. Without magnesium assisting, many enzymes would not be able to make new proteins in the body nor could we get energy from our foods. Without enough vitamin D, the body’s cells, organs and systems can not function normally.
A constant supply of calcium and magnesium is critical to each and every cell. If we do not eat enough of these minerals throughout the day, our bodies can make an emergency withdrawal from the “bank”—the bones. More than half of the body’s magnesium and 99 percent of the body’s calcium are found in the bones and teeth. The bone bank is not so different from a regular bank. If no deposits are made, frequent withdrawals will soon deplete the account. If a healthy mineral balance is not maintained over the years, the bones begin to weaken and osteoporosis can develop.
Vitamin D, is known as the “sunshine vitamin” because exposure to sunlight triggers our bodies to produce it. Vitamin D helps to regulate calcium metabolism and normal calcification of the bones of the body. In addition, Vitamin D influences the use of the mineral phosphorous. Phosphorous and calcium together with other minerals make up our bones. Think of these three minerals; calcium, magnesium, and Vitamin D, as “the Dynamic Trio” which scientists and medical researchers are today finding out play a more important role in the body and the health of the body than were known before.
Healthy bones and teeth require magnesium. About sixty percent of the body’s magnesium resides in the bones. There it works to give some flexibility to the bones and also serves as a storage site for the rest of the body. Only 1% of magnesium is found in blood; thus serum magnesium levels are a poor reflection of magnesium stores, and the simplest measure would be RBC magnesium levels. The remaining magnesium is in intracellular storage. Magnesium may help prevent cavities by holding calcium in the enamel of the tooth.
Magnesium is required for more than 300 chemical reactions in the human body, affecting cardiac function, bowel function, blood sugar control, BP, and bone health. Not surprisingly, then, magnesium deficiency plays a role in cardiac deaths, poor BP control, and GI problems, in particular constipation. It acts as a catalyst, or sort of a spark plug, to trigger the reactions that provide energy to the cells. It is an essential part of the cell’s machinery to build and repair proteins. Magnesium promotes the relaxation phase of muscle activity and, along with calcium, helps nerve cells communicate with each other in the nervous system.
Drinking soft water decreases magnesium intake. Other magnesium depleters are: diuretic drugs, alcohol, sugar, and caffeine. Decreased levels of magnesium are related to high blood pressure, kidney stones, and coronary heart disease.
The best food sources of magnesium are seeds, nuts, beans, soybeans, seafood, and dark green vegetables like spinach. Magnesium is actually a part of the chlorophyll molecule. Chlorophyll is a pigment that gives plants their rich green color. Not only are 75%-85% of U.S. diets deficient in magnesium (the average diet contains 50%-60% of the RDA), but several common factors lead to magnesium depletion, including diuretic use, elevated glucose levels, diarrhea, alcohol intake, and malabsorption related to GI diseases. Complicating magnesium deficiency is that adding calcium supplements alone blocks magnesium absorption and worsens what is already a national magnesium deficiency problem. This problem is made worse by the lack of quality clinical outcome studies identifying the optimal calcium/magnesium supplement recommendation. Expert opinion regarding combining these supplements ranges from a 1:1 to 3:1 calcium/magnesium ratio. Symptoms associated with magnesium deficiency include muscle cramps, tingling, numbness, abnormal heart rhythms, coronary spasm, seizures, confusion, disorientation, loss of appetite, and depression. Magnesium is commonly supplemented in the form of magnesium oxide, but this frequently acts as a GI irritant and many people complain of GI upset with adequate dosing. Better-absorbed and better-tolerated forms of magnesium would include chelated magnesium (protein-bound rather than salt-bound), magnesium citrate, or magnesium glycinate.
Vitamin D has co-factors that the body needs in order to utilize vitamin D properly. Magnesium is the most important co-factor for vitamin D. In fact, it is common for rising vitamin D levels to exacerbate an underlying magnesium deficiency. If one is having problems supplementing with vitamin D, a magnesium deficiency could be the reason why. Magnesium is a mineral that is essential to all cells of all known living organisms. Every major biological process, including protein and nucleic acid synthesis and cellular energy production, requires adequate amounts.
Inadequate blood magnesium levels are known to result in low blood calcium levels, resistance to parathyroid hormone, insulin resistance, increased risk of type 2 diabetes, and resistance to some of the effects of vitamin D. It is the fourth most abundant mineral in the body, for it is involved in more than 300 biochemical reactions. All the enzymes that metabolize Vitamin D require Mg. It is also required in each of the steps concerned with replication, transcription, and translation of genetic information, and thus it is also needed for the genetic mechanism of action of Vitamin D.
Although most of us associate calcium with strong bones and teeth, calcium plays other important roles in our bodies. Calcium is required for movement of our muscles, for the clotting of our blood after a cut or a wound, for normal activity of our nerves, and for the regulation of our blood pressure. In addition to being a factor in osteoporosis, poor calcium nutrition may contribute to colon cancer, to hypertension (high blood pressure), and to preeclampsia, a disease causing high blood pressure during pregnancy. More recently, calcium deficiency has also been associated with weight control and metabolic rate. Calcium deficiency is of high clinical importance, as the average diet contains only 40%-50% of the RDA (800-1,200 mg daily, varying with age and gender). Daily intake of 1,500 mg is recommended for people with osteopenia or osteoporosis. More than 2,000 mg of calcium daily is excessive and has been associated with an increased cancer risk. Too often, physicians recommend calcium supplementation without assessing dietary calcium intake, which leads to inappropriate calcium dosing. Subtracting the amount of calcium in foods ingested (see box below) from the patient’s calcium-intake goal will yield the amount of calcium that must be provided from either a supplement or a daily food source.
In 2003, researchers at Dartmouth confirmed that deficiencies of both vitamin D and calcium were involved in the reoccurrence of colon polyps, a condition known to lead to colon cancer. It turns out both calcium and vitamin D work together to prevent colon cancer.
What is Vitamin D Deficiency?
Definition of vitamin deficiency:
“A vitamin deficiency is any condition in which inadequate intake of a vitamin results in significant dysfunctions or disease.”
“Conversely, vitamin adequacy is the situation in which further increases in intake produce no further reduction in dysfunction or disease.”
There is no way to know for certain if you are vitamin D deficient until you get a 25-hydroxyvitamin D test, also called a 25(OH)D test.
Vitamin D (25-hydroxyvitamin D) blood levels, the barometer for vitamin D status, are measured in nanograms per milliliter (ng/mL) or nanomoles per liter (nmol/L), where ng/ml = 0.4 nmol/l.
Levels should be above 50 ng/mL (125 nmol/L) year-round, in both children and adults. Thanks to Bruce Hollis, Robert Heaney, Neil Binkley, and others, we now know the minimal acceptable level. In a recent study, Heaney, et al expanded on Bruce Hollis’s seminal work by analyzing five studies in which both the parent compound (cholecalciferol) and 25(OH)D levels were measured. They found that the body does not reliably begin storing cholecalciferol in fat and muscle tissue until 25(OH)D levels get above 50 ng/mL. The average person starts to store cholecalciferol at 40 ng/ml (100 nmol/L), but at 50 ng/mL (125 nmol/L) virtually everyone begins to store it for future use. That is, at levels below 50 ng/mL, the body uses up vitamin D as fast as you can make it, or take it, indicating chronic substrate starvation—not a good thing.
25(OH)D3 levels should be between 50–90 ng/mL year-round.
Children and adults need a vitamin D blood level >8 ng/ml to prevent rickets and osteomalacia (demineralization and softening of bones) respectively. It takes a concentration >20 ng/ml to keep parathyroid hormone levels in a normal range. A level >34 ng/ml is required to ensure peak intestinal calcium absorption. Finally, neuromuscular performance steadily improves in elderly people as vitamin D levels rise up to 50 ng/ml. Accordingly, a vitamin D blood level <8 ng/ml is regarded as severely deficient; 8–19, deficient; and 20–29, insufficient, i.e., too low for good health. A level >30 ng/ml is sufficient, but experts now consider 50–90 ng/mL to be the optimal level of vitamin D. Levels 100–150 ng/ml are excessive and >150 ng/ml, potentially toxic.
In order to enjoy optimal health, we should maintain a vitamin D blood level of ≥50–90 ng/mL. Without sun exposure, to reach a level of 50 ng/ml requires taking a 5,000 IU/day vitamin D supplement, with variations for the multiple factors that affect the amount each individual needs. Vitamin D in a physiologic dose (5,000 IU/day) prevents the build up of calcium in blood vessels. If one takes 10,000 IU of vitamin D a day and spends a lot of time in the sun, it would be prudent to check vitamin D blood level to ensure that it does not exceed 100 ng/ml.
There are many degenerative diseases that have been associated with vitamin D deficiency such as cancer, heart disease, diabetes, osteoporosis and arthritis. There are also many infectious diseases that are effectively treated with vitamin D. However, the effects of vitamin D on the common bacteria and viruses should not be overstated. It is very effective with prevention and effective with treatment, but your body’s ability to fight off infections is also dependent on other factors such as your overall immune strength, how lethal the parasite is, etc. So far, there has not been enough evidence to call vitamin D a cure, although it is a very effective treatment against a variety of infectious diseases.
Remember that association does not mean causation. If A is associated with B, then A could cause B, B could cause A, or a third factor(s), C, perhaps could cause both A and B. “Could” and “Perhaps” being the key words. Remember, most of the serious errors in psychiatry and medicine are made when associations are confused with causation; or when subsequence is confused with consequence; or when facts are confused with theory.
Cardiovascular Disease- Vitamin D expresses genes that curb cardiovascular disease. One gene controls the renin-angiotensin system, which when over-reactive causes hypertension (high blood pressure). Others stifle the immune system-mediated inflammatory response that propagates atherosclerosis and congestive heart failure.
Cancer– Major reductions in incidence of cancers has been reported with adequate vitamin D levels. Vitamin D has been shown to be protective against 16 types of cancers so far. 6 types of cancer (breast, colon, endometrial, esophageal, ovarian and non-Hodgkin’s lymphoma) were inversely correlated to solar UVB radiation exposure and rural residence in combination. Another 10 types of cancer (bladder, gallbladder, gastric, pancreatic, prostate, rectal and renal) were inversely correlated to UVB but not urban residence. Some of the genes vitamin D activates make proteins that halt cancer cells by inducing apoptosis (programmed cell death) which destroys aberrant cells like adenoma in the colon and rectum. Others promote cell differentiation and reigning in out of control growth of cancer cells (like prostate cancer cells). Vitamin D expressed genes inhibit angiogenesis, the formation of new blood vessels that malignant tumors need to grow, as studies in lung cancer and breast cancers show. Other genes inhibit metastases, preventing cancer that arises in one organ from spreading its cells to other parts of the body, as studied in breast and prostate cancers. If you have cancer, please remember that vitamin D is not a cure-all and should never be used as a main treatment for cancer. Your oncologist will prescribe treatment that has proven efficacy and you should carefully follow their advice as the mainstay of treatment. At the same time, you should know that evidence suggests that the proper amount of vitamin D will help you in your fight against cancer. However, somewhere along the line, the vitamin D and cancer story took a tragic twist. No one seemed to care that optimal doses of cholecalciferol would raise tissue levels of calcitriol quite high, would not cause hypercalcemia, and should work well against cancer. Remember, cholecalciferol occurs naturally, cannot be patented, and is dirt cheap. As vitamin D could not be patented, it held little interest for the medical industry. The idea that it could help cancer offered no financial incentives to drug companies or researchers hoping to discover a drug they could patent. Plain vitamin D3 held no promise for financial gain for drug companies or for the researchers who are often financially involved in such companies. Also, few of the scientists working to cure cancer had any but the most rudimentary understanding of basic vitamin D physiology, pharmacology, or toxicology. Therefore, the medical industry seemed to ignore the evidence that simple vitamin D helped prevent many cancers and that adequate vitamin D nutrition may help retard the growth of cancer. The medical industry turned their attention instead to developing chemical modifications of the most active form of vitamin D, calcitriol. Called vitamin D analogs, these drugs held the promise for a tremendous profit if studies showed they were active against cancer. Although good reasons existed to support clinical trials with plain, natural vitamin D in cancer patients, the medical industry concentrated on developing vitamin D analogues instead. To date, more than 2000 such analogues have been developed and some have been tested on cancer patients. The results have been disappointing because the drugs cause high blood calcium via the endocrine function of vitamin D. The possibility that such analogs may help cancer patients should not be discounted. However, development of the analogs bypassed a crucial and ethical medical question: Does plain vitamin D3 help cancer patients? The medical industry was not interested in the answer to this question and instead concentrated on forming numerous companies to exploit the potential anti-cancer properties of vitamin D analogs.
Autoimmune Disorders- Vitamin D is important for the prevention of just about every single autoimmune disease. And studies have shown that immune function is connected with just about all nervous system disorders. People that live at high latitudes have an increased risk of MS an other autoimmune diseases.
Inflammation- Inflammation is nothing more than an abnormal immune response. There are many diseases of excess inflammation. Vitamin D helps the body from over reacting and controls inflammation. In these cases, it is more important for our immune systems to become smarter, not necessarily stronger. And vitamin D does that. It can suppress the immune system and fight diseases like arthritis, lupus and multiple sclerosis.
Pregnancy Complications/ Birth Defects/ Developmental Disorders– Vitamin D is essential for the normal physical and mental development throughout the fetus, infant and adult years. Nursing mothers must have optimal vitamin D levels to provide enough vitamin D for their babies. Even vitamin levels in the womb affect the health of the baby much later in life. And since large majority of pregnant women in the US are vitamin D deficient, many infants and children do not receive an adequate intake of vitamin D in the womb, and afterwards, even when exclusively breast fed. Thus, they are at much higher risk of birth defects and developmental disorders. While the RDA for pregnant and lactating women has been stuck between 600-800 IU for decades, more recent research suggests that this number needs to be much higher. The latest of these studies showed that women taking 4000 IU per day during pregnancy still had babies that were born deficient, but had fewer infections than women taking 400 or 2000 IU per day, and had half of the pregnancy or labor complications as women taking 400 IU per day. Studies of 1000, 2000, 4000, 6400 IU of vitamin D show that only mothers that were taking 6400 IU per day were able to make enough vitamin D to meet their baby’s RDA of vitamin D.
Brain Disorders- vitamin D plays a role in mental illness based on the following five reasons: 1)Epidemiological evidence shows an association between reduced sun exposure and mental illness. 2) Mental illness is associated with low 25-hydroxyvitamin D [25(OH)D] levels. 3) Mental illness shows a significant comorbidity with illnesses thought to be associated with vitamin D deficiency. 4) Theoretical models (in vitro or animal evidence) exist to explain how vitamin D deficiency may play a causative role in mental illness. 5) Studies indicate vitamin D improves mental illness. Professor John McGrath and Dr. Darryl Eyles of the University of Queensland in Australia have repeatedly warned us that normal brain development depends on adequate amounts of activated vitamin D to orchestrate the cellular architecture of the brain. Both the vitamin D receptor and the enzyme necessary to make activated vitamin D are present in a wide-variety of human brain tissues very early in pregnancy. Production of the vitamin D receptor in the developing mammalian brain rises steadily beginning several weeks after conception where activated vitamin D induces the expression of nerve-growth-factor and stimulates brain cell growth. Dr. Almeras, Professor Feron, and their group at the University of the Mediterranean in Marseilles found developmental vitamin D deficiency disrupts 36 proteins involved in mammalian brain development. The amount of activated vitamin D in the brain directly depends on the amount of vitamin D made in the skin, or ingested orally. Evidence that vitamin D affects mental abilities comes from a series of 14 controlled studies evaluating the effect of vitamin D-containing multivitamins on childhood intelligence. All 14 studies they reviewed reported small (1–2%) to modest (5–6%) improvements, usually in nonverbal IQ. Lancet published the first study in 1988. More interestingly, most studies showed no effect on the majority of children but very significant effects (15% gains) in about 20% of children, perhaps the vitamin D-deficient subgroup. Something in the multivitamins helped some of the children’s brains quite a bit.
Infectious Diseases– The antimicrobial peptides kill a broad spectrum of bacteria, viruses and fungus.
There is much more than vitamin D does, but that will be discussed in future posts.
How much vitamin D do I Need?
This is a difficult question because it relies on so many personal factors. Everyone’s situation is either a lot, or at least a little, different. How much vitamin D you need to keep your vitamin D at healthy levels between 50–90 ng/mL varies with age, body weight, percent of body fat, latitude, skin coloration, season of the year, use of sun block, individual variation in sun exposure, and probably how ill you are. As a general rule, old people need more than young people, big people need more that little people, heavier people need more than skinny people, northern people need more than southern people, dark-skinned people need more than fair-skinned people, winter people need more than summer people, sunblock users need more than non-users, sun-phobes need more than sun worshipers, and ill people may need more than well people. But these general guidelines are often broken. Each individual has a different requirement for vitamin D.
Quite a few factors are involved, as you can see. However, don’t feel bad, no one fully understands it. Vitamin D is used by the body—metabolically cleared—both to maintain wellness and to treat disease. If you get an infection, how much vitamin D does your body use up fighting the infection? If you have cancer, how much vitamin D does your body use up fighting the cancer? If you have heart disease, how much vitamin D does your body use up fighting the heart disease? If you are a child with autism, how much vitamin D does your brain need to turn on the genes that autism has turned off? If you are an athlete, how much vitamin D does your body use to make you stronger and quicker? Nobody knows the answer to these questions right now.
With the current data available, it is not possible to estimate the precise need for vitamin D in a specific individual because of the multiplicity of factors, some of which are still unknown, that determine vitamin D needs. Individual need can only be determined by assessing the blood level of 25-hydrxyvitaminD and adjusting dosage to maintain a healthy range between 50–90 ng/mL (or 125–247 nmol/L) year-round. Continuing reassessment is recommended (every few months) as needs change with season, weight, lifestyle and age. This may add a few dollars to your medical costs but the health gains made such as improved bone integrity, healthier muscles, less depression, less hypertension, reduced chance of inflammation, diabetes, cancer, heart and cardiovascular disease and auto-immune and neurological disorders will more than compensate.
Current Government Recommendations
The Government has an impossible job. They need to make a one-size-nearly-fits-all guideline while factoring in all of the individual variations for the production of vitamin D. As with other steroid hormones, doses need to be individualized. Vitamin D requirements vary within a wide range. There are general rules regarding body size, skin pigmentation, age, etc. However, these “rules” are often broken. Nobody can gauge your vitamin D requirement without a blood test: 25-hydroxyvitaminD test or 25(OH)D test. Serum vitamin D levels should be rechecked periodically and dosage should be adjusted accordingly.
Notes: The biological activity of 1 mcg = 40 IU,
1 ng/mL = 2.496 nmol/L
RDA- Recommended Dietary Allowance– Determined by the Food and Nutrition Board (FNB). It is “supposedly” the average daily level of intake sufficient to meet the nutrient requirements of nearly all (97-98%) healthy people. However, according to Robert Heaney MD, a prominent researcher that served as a member of the FNB over a decade ago to help establish the RDA for vitamin D, the RDA of 200 IU per day was originally developed to represent the amount that should be consumed on a daily basis to avoid rickets. This is troubling because vitamin deficiency can cause significant problems at levels that are not extreme enough to cause rickets. The current RDA is based on Data from 1989. It relies on data from over 20 years ago. It does not take into consideration all of the clinical data collected by scientists and researchers in the past two decades. They recommend 200 IU per day for people 50 years old or younger. 400 IU (10 mcg) per day for people older than 50 and 600 IU for people over 70. The research used to determine vitamin D’s RDA indicates that blood levels of 25(OH)D in “healthy individuals” range from 20 ng/mL to 37.5 ng/mL. However, this range only represents the typical vitamin D level for an average person. And by today’s standards (50–90 ng/mL for healthy people), the average person is far from being in optimal health.
AI- Adequate Intake– Determined by the National Institute of Health (NIH), Office of Dietary Supplements. AI is established when evidence is insufficient to develop a RDA and is set at a level that is assumed to ensure nutritional adequacy. AI for vitamin D is based on the assumption that the vitamin is not synthesized by exposure to sunlight. They recommend 200 IU (5mcg) per day for males and females between the ages of 19-50. And 400-600 IU per day for males and females above 50.
RDI- Reference Daily Intake– Is established by the Food and Drug Administration (FDA) for use in nutrition labeling. It is based on the 1968 RDAs. They recommend 200-400 IU (10 mcg)
DRI- Daily Reference Intake– Determined by FNB. Supposed to replace previous RDAs. Was set in 1997. This is the most recent set of dietary recommendations established by the FNB of the Institute of Medicine (IOM) for vitamin D. They recommend 200 IU per day for people 50 years old or younger. 400 IU (10 mcg) per day for people older than 50 and 600 IU for people over 70.
UL- Upper Intake Level– Upper level of intake considered to be safe for use by adults, incorporating a safety factor. Maximum daily intake unlikely to cause adverse health affects. Set at 2000 IU (50 mcg).
NAHEL- No Adverse Health Effect Level- This level is determined by the National Academy of Sciences (NAS). According to the NAS research, scientific concerns about this level of intake are minimal. Set at 2400 IU
DV- Daily Value– The FDA requires supplement and food labels to contain percentages of daily recommended values. If you look at the label on the back of food or supplement packaging, you will see a list of nutrients that specifies the amount of each nutrient contained in single serving of the product and what percentage of the recommended Daily Value that this amount represents. The FDA requires food and supplement manufacturers to include this information on the labels of their products to help the consumer determine how much of your daily recommended allowance you are consuming. The Daily value is the recommended daily intake of a particular nutrient and is generally based on a 2000 calorie diet. For vitamins and minerals, the Daily Value is based on the RDI, which is based on the older RDA. The primary shortcoming with the DV is that they are based on the RDA. In many cases, the RDA is nothing more than the minimum amount of a nutrient needed to prevent a particular condition that is caused by a deficiency of the same nutrient. This is misleading because the amount of a nutrient needed to prevent a disorder can be significantly lower than the amount needed to support optimal function and health.
In one study, it was stated that the average American consumes 30-50 IU per day of vitamin D. That is less than one-tenth of what the government recommends, and @ one-hundredth of what the average healthy 150 lbs adult utilizes each day (@4000 IU per day) if it is available. And we must also remember that the bigger you are, the more vitamin D you require. And an already deficient person will need more to regain optimum levels. If your body has problems synthesizing vitamin D, you may need more. Thus, many Americans are deficient in vitamin D.
The 2001-2004 National Health and Nutrition Examination Survey (NHANES) provides more recent data on the vitamin D nutritional status of the U.S. population. According to the study, 50-78% of the US population had serum 25(OH)D levels < 30 ng/mL. The mean serum level in the US between 2001-2004 was 24 ng/mL, 6 ng/mL lower than in the 1988-1994 collections period. It is important to note again that the new established healthy range is between 50–90 ng/mL year-round. It has been noted that the government recommended supplemental intake of 400 IU per day increased 25(OH)D concentrations by only 2.8-4.8 ng/ml and that daily intake of 1,700 IU is needed to raise the concentrations from 20 to 32 ng/ml, which is still considered deficient.
Despite the fact that many experts consider the RDA for vitamin D to be far too low, this is by no means justification to ignore the values recommended by the Government. It is just another indication that everyone needs to take responsibility and educate yourself so you can make more informed decisions based on your health.
Many experts are now recommending supplementation of 1000-6000 IU per day for 2-3 months and then adjusting your dosage based on your 25(OH)D serum levels. Anthony Norman, professor emeritus of biochemistry and of biomedical sciences at UC Riverside, and Cedric Garland, an adjunct professor of family and preventative medicine at UC San Diego have joined a group of 18 experts urging the US government to increase its recommended daily vitamin D intake to 2000 IU per day for most adult Americans. Norman has been studying vitamin D for more than 45 years. In 1967, his laboratory discovered that the vitamin is converted into a steroid hormone by the body. Two years later, his laboratory discovered the vitamin D receptor (or VDR) which is an essential receptor in more than 36 target organs of the body that responds biologically to the vitamin.
How can I get enough Vitamin D?
Natural Sunlight and UVB Rays
There are two types of ultra-violet radiation waves. Ultra-violet A (UVA) rays are known to cause cancer. It also destroys collagen and vitamin D on the skin and causes many of the skin problems associated with UV rays. Ultra-violet B rays produce vitamin D when it makes contact with skin.
The best times to make high quantities of vitamin D are during mid-day (10a.m.- 3p.m.) when the sun is highest, on days when the UV index is higher than 3, and during late spring, summer and early fall. Early in the day and late in a day, sunlight provides only UVA which doesn’t help us make vitamin D but can still cause skin damage. The closer you get to solar noon, the more UVB rays are available. Your shadow should be shorter than your height. If your shadow is taller than you, you will get a tan but not produce any vitamin D. The UVB rays need direct contact with unclothed skin that is not covered by sunblock. Expose as much skin as possible (50-75%) without getting burned.
It is important to stress that it is important to avoid getting sunburned and should only implement sun exposure gradually. While we all benefit from regular exposure to the sun, it is important to recognize that you should always limit exposure to avoid getting burnt. Sunburn has been clearly related to an increased risk of skin cancer. Interestingly though, if you avoid getting sunburned yet have regular sun exposure, you will have a decreased risk of melanoma. Optimizing your sun exposure in this way also reduces your risk of 16 other cancers. Still, people have a tendency to focus on the negative rather than the positives, and continue to frighten others about sun exposure. Humans were all designed to have regular sun exposure. It is very similar to water. Just because you can drown while swimming does not mean that you should avoid drinking water or not swim in it. As long as you avoid sun exposure that will cause burning, it will help improve your health.
It is a complicated issue though. Skin cancer in the United States is largely related to the over-abundance of omega-6 oils consumed. When sunlight hits these fats it can convert them into cancer causing molecules, and if not healthy, cancer can develop. This cancerous transformation does not happen with omega-3 fats. So, changing the ratio of omega-3 to omega-6 oils in your diet is one of the key ways to prevent this.
Most sunblock products in the United States are formulated to block the essential UVB rays while allowing the harmful UVA rays to penetrate the skin. (Newer sunscreen lotions also block out UVA.) Sunblock with a sun protection factor (SPF) of 8 or higher appear to block most UVB rays. The FDA so far has failed to finalize UVA standards for sunscreen. In direct contrast, standards in the EU, Japan and Australia require that sunscreens protect the skin from damaging UVA rays. Also, in contrast to the FDA’s blanket advice to stay out of the sun between 10a.m. to 4p.m., and the American Academy of Dermatology’s advice to avoid intentional sunlight exposure for any length of time, the American Medical Association (AMA) recommends 10 minutes of sun exposure before applying sunscreen to give the skin time to make vitamin D. Sunblock can prevent sunburns and other skin problems but does nothing to prevent skin cancer (melanoma). In fact, since it blocks UVB rays (which prevents cancer) and allows the harmful UVA rays (which cause cancer) to destroy vitamin D, it can be said that the use of sunblock may actually increases one’s chances of getting cancer. The statistics seem to back this up. Since sunblock products entered the consumer market 30 years ago, the cases of skin cancer has actually risen. Also, skin cancers often show up on areas that have not been damaged by the sun. This suggests that sunlight exposure is not the only factor in skin cancer. Furthermore, 3 out of the 5 major chemical ingredients in sunblock are abrsorbed into the skin directly into systemic circulation. The FDA only checks to see that it blocks UV rays and they do not bother to check if ingredients in sunblock have trans-dermal properties or its implications when it enters systemic circulation.
Glass also blocks virtually all UVB rays, thus blocking the production of vitamin D so avoid glass from getting between you and the sun. UVB rays also enter the body through the eyes and stimulate the pineal gland. Sunglasses block UVB rays from entering your body through your eyes.
At solar noon, 1 minute of full body sun exposure produces @ 1000 IU. Studies have shown that if you go out in the summer sun in your bathing suit until your skin just beings to turn pink, you make between 10,000 and 50,000 IU (international units) of cholecalciferol in your skin. 20,000 IU seem to be an acceptable average. (Although it is important to remember the various factors that affect vitamin D production in individuals) That means that 10- 30 minutes in the summer sun produces 100 times more vitamin D than the government says you need (200 IU). However, there is no reason to worry. As mentioned earlier, you body has a fool proof method of limiting cholecalciferol. This is the reason why no one has ever reported to develop vitamin D toxicity from the sun, although it is possible when taking vitamin D orally. An equilibrium occurs in white skin after 20 minutes of sun exposure, at which point further increases in vitamin D is not possible, because the UV light will start to degrade the vitamin D.
A common misconception is that occasional exposure of your face and hands to sunlight is sufficient for vitamin D nutrition. Indeed, this exposure can provide 400-600 IU during those months when appropriate months when sunlight is available. But for most of us, this is an absolutely inadequate exposure to move vitamin D levels to the healthy range.
Each individual’s production of cholecalciferol depends on factors such as age, body weight, percent of body fat, latitude, skin coloration, season of the year, use of sunblock, individual variation in sun exposure, and how ill you are. It is known now that dark skinned people absorb less UVB rays than light skinned people, making a connection with the common diseases that dark skinned people suffer from (heart disease, hypertension, cancer and stroke) and the same diseases associated with vitamin D deficiency. People that live above latitude of 35 degrees (north of Atlanta and Los Angeles) do not receive enough year round UVB from sunlight. During winter months, people that live in higher altitudes have much lower vitamin D blood levels than during the summer months.
Remember that our ancestors lived naked in the sun for several million years. We evolved in equatorial Africa where the sun, shining directly overhead, supplies inhabitants with year round UVB photons for making vitamin D. Our African ancestors absorbed much higher doses of vitamin D compared to most humans today. Especially in the US. Around 50,000 years ago, a mutation occurred that is supposedly responsible for the appearance of white skin in humans. White skin, with less melanin, synthesizes vitamin D in sunlight much faster than dark skin. People possessing this mutation were able to migrate north and south to places with less sun. Then we put on clothes, started working inside and living where buildings blocked the sun. Then we started traveling in cars instead of walking or riding horses, and glass blocked even more UVB in sunlight. When we were children we were told that sunshine was great and that we needed the sun to be healthy. Then, only a few years ago, we started being told that be needed to actively avoid the sun and if we had to go outdoors, to put on sunblock. All this time humans have been steadily reducing the tissue levels of the most important steroid hormone in the body. The really significant reductions in sunlight exposure have occurred since the industrial revolution, coinciding with greatly increase in diseases like cardiovascular disease, diabetes, and cancer.
The majority of the world now lives above 35 degrees North and is unable to synthesize vitamin D from sunlight due to angle of the sun. At a large solar zenith angle, ozone in the upper atmosphere will completely block UVB radiation. In Seattle (47 degrees N) and London (52 degrees N), from October to April UVB photons are blocked by the atmosphere and one’s skin can not make vitamin D. (The half life of circulating vitamin D is approximately 1 month)
Some observations that doctors and researchers have made regarding sunlight and disease:
- Where there is less sun, there are more cases of cancer, colds, influenza, autism and other diseases associated with vitamin D deficiency.
- These diseases are much more prevalent during winter season, when there is the least amount of sunlight.
- The further away you are from the equator, these same diseases become more and more prevalent. The further away you go from the equator, less sunlight is available.
- Cases of skin cancer have risen since the introduction of sun-screening products into the US market.
- Sunlight has positive effects on bone integrity, high blood pressure, depression, sleep disorders, ADHD, PMS, acne and more.
- The vast majority of people in the US can not possibly receive enough UVB exposure to generate optimum levels of vitamin D from September to mid-April.
- In northern US cities, it is impossible to get adequate vitamin D from sunlight in any season.
- It is impossible to get vitamin D toxicity from too much sun exposure. Your body will not let that happen. That is why receiving vitamin D from the sun in the best option whenever possible.
If you can not get enough vitamin D from natural sunlight, tanning beds can be an effective replacement when using the proper equipment and in safe, limited doses. However, many experts contend that there have not been enough studies to accurately determine what the appropriate dosage is. Also, they say that sun tanning is not a regulated industry and there are many risks associated with it. They claim that supplements are a safer alternative to natural sunlight.
Not all tanning beds are the same. Some use light bulbs that emit only UVA rays, some that emit UVA and UVB, and some emit UVA, UVB and UVC rays. Plus, the percentages of UVA to UVB vary among machines. UVC is normally blocked by the ozone and very damaging and should be avoided. UVA is also damaging to collagen and destroys vitamin D, but causes the skin to tan quickly and is preferred by tanning salons. So only the bulbs that emit UVB can have any potential benefit when used correctly and in the appropriate dose.
If one were to decide to use artificial tanning machines to get their vitamin D, they should use the old fashioned tanning beds that provide 6-7% UVB radiation and 93-94% UVA which is the optimal concentration that nature offers during the summer solstice. Stay away from the high pressure tanning beds that give only 1% UVB rays and 99% UVA rays. When in doubt about the equipment or the people servicing it, it’s better to be safe than sorry. Those lights that tanning salons use are very strong and have a UV index of @7-8.
Here is what the experts are recommending based on the most recent research:
If you can not find a way to get adequate UVB Rays, supplementation may be your only option. Healthy children under the age of 1 years should take 1,000 IU per day—over the age of 1, 1,000 IU per every 25 pounds of body weight per day. Well adults and adolescents should Take 4,000-6,000 IU per day for 2–3 months, and then obtain a 25-hydroxyvitamin D test. Adjust your dosage so that blood levels are between 50–90 ng/mL year-round. To obtain this amount from milk one would need to consume 10-15 quarts of milk every day. 1 quart of milk contains @ 400 IU. This is not advisable. Instead of the multi-vitamins that only contain the Government recommended 200-400 IU, many pharmacies have vitamin D3 cholecalciferol supplements in 1000 and 2000 IU tablets or gelcaps. It is also available in liquid form. Health food stores typically do not sell vitamin D3 in 5,000 or 50,000 IU tablets, but they are readily available online in both 5,000 and 50,000 IU tablets of Vitamin D3. Some people prefer to take one 50,000 IU tablet a week (equivalent to 7,100 IU a day) and a three-day course of 150,000 IU vitamin D at the first sign of a cold.
Start supplementing with the vitamin D before you have the blood test. Then adjust your dose so your 25(OH)D level is between 50–80 ng/ml (125–200 nmol/L), summer and winter. But remember, these are conservative dosage recommendations. Most people who avoid the sun—and virtually all dark-skinned people—will have to increase their dose once they find their blood level is still low, even after two months of the above dosage, especially in the winter. Some people may feel more comfortable ordering the blood test before they start adequate doses of vitamin D. We understand. Test as often as you feel the need to, just remember, no one can get toxic on the doses recommended above and some people will need even more.
Vitamin D Toxicity
“Nothing is without poison. Dosage alone determines the toxicity.”
Is vitamin D toxic? Not if we take the same amount nature intended when we go out in the sun. Vieth attempted to dispel unwarranted fears in medical community of physiological doses of vitamin D in 1999 with his exhaustive and well-written review.
His conclusions: fear of vitamin D toxicity is unwarranted, and such unwarranted fear, bordering on hysteria, is rampant in the medical profession.
In 1999, Vieth indirectly asked the medical community to produce any evidence 10,000 units of vitamin D a day was toxic, saying “Throughout my preparation of this review, I was amazed at the lack of evidence supporting statements about the toxicity of moderate doses of vitamin D.” He added: “If there is published evidence of toxicity in adults from an intake of 250 ng (10,000 IU) per day, and that is verified by the 25(OH)D concentration, I have yet to find it.”
Like most medication, cholecalciferol is certainly toxic in excess, and, like Coumadin, is used as a rodent poison for this purpose. Animal data indicates signs of toxicity can occur with ingestion of 0.5 mg/kg (20,000 IU/kg ), while the oral LD50 (the dose it takes to kill half the animals) for cholecalciferol in dogs is about 88 mg/kg, or 3,520,000 IU/kg. This would be equivalent to a 110-pound adult taking 176,000,000 IU or 440,000 of the 400 unit cholecalciferol capsules. Vieth reports human toxicity probably begins to occur after chronic daily consumption of approximately 40,000 IU/day (100 of the 400 IU capsules). Heavy sun exposure when combined with excessive supplement use is a theoretical risk for vitamin D toxicity, but if such a case has been reported, we have yet to hear of it. Physician ignorance about vitamin D toxicity is widespread. A case report of four patients appeared in the 1997 Annals of Internal Medicine, accompanied by an editorial warning about vitamin D toxicity. However, careful examination of the patients reveals that both papers are a testimony to the fact that incompetence about vitamin D toxicity can reach the highest levels of academia.
Cholecalciferol (D3), Not Ergocalciferol (D2), Is Safe
Although there are documented cases of pharmacological overdoses from ergocalciferol, the only documented case of pharmacological—not industrial—toxicity from cholecalciferol we could find in the literature was intoxication from an over-the-counter supplement called Prolongevity. On closer inspection, it seemed more like an industrial accident but it was interesting because it gave us some idea of the safety of cholecalciferol. The capsules consumed contained up to 430 times the amount of cholecalciferol contained on the label (2,000 IU). The man had been taking between 156,000–2,604,000 IU of cholecalciferol a day (equivalent to between 390–6,500 of the 400 unit capsules) for two years. He recovered uneventfully after proper diagnosis, treatment with steroids, and sunscreen.
It is true that a few people may have problems with high calcium due to undiagnosed vitamin D hypersensitivity syndromes such as primary hyperparathyroidism, granulomatous disease, or occult cancers, but a blood calcium level, PTH, 25(OH)D, and calcitriol level should help clarify the cause of the hypersensitivity. Although D can be toxic in excess, the same can be said for water.
We know that psychotic patients should drink about 8 glasses of water a day. However, many would hurt themselves by regularly drinking 40 glasses a day (called compulsive water intoxication). So you could say that water has a therapeutic index of 5 (40/8).
Heaney’s recent research indicates that healthy humans utilize about 4,000 units of vitamin D a day (from all sources). However, 40,000 units a day, over several years, will hurt them. Therefore, vitamin D has a therapeutic index of 10 (40,000/4,000)—twice as safe as water. We are not saying vitamin D is as safe as water, we are saying vitamin D is safe when used in the doses nature uses.
Children have never gotten into a medicine cabinet and overdosed from vitamin D. This has happened countless times with other over the counter medicines such as Tylenol and asprin.
Sun Supplies 10,000 Units Of Vitamin D
The single most important fact anyone needs to know about vitamin D is how much nature supplies if we behave naturally, e.g., go into the sun. Humans make at least 10,000 units of vitamin D within 30 minutes of full body exposure to the sun, what is called a minimal erythemal dose. Vitamin D production in the skin occurs within minutes and is already maximized before your skin turns pink. Also, the skin produces endorphins when sunlight hits skin. These are the same endorphins that their body makes when you exercise. Your body has a natural system of giving you a dose of narcotics when you sunbathe.
Fear of the fatal form of skin cancer, malignant melanoma, keeps many people out of the sun. The problem with the theory is that the incidence of melanoma continues to increase dramatically although many people have been completely avoiding the sun for years. Sunburns are not safe. But brief, full-body sun exposure (minimal erythemal doses) will lower your chances of dying of vitamin D deficiency related illnesses.
Furthermore, there was not even one death caused by a dietary supplement in 2008, according to the most recent information collected by the U.S. National Poison Data System. The new 174-page annual report of the American Association of Poison Control Centers, published in the journal Clinical Toxicology, shows zero deaths from multiple vitamins; zero deaths from any of the B vitamins; zero deaths from vitamins A, C, D, or E; and zero deaths from any other vitamin.
Additionally, there were no deaths whatsoever from any amino acid or herbal product. This means no deaths at all from blue cohosh, echinacea, ginkgo biloba, ginseng, kava kava, St. John’s wort , valerian, yohimbe, Asian medicines, ayurvedic medicines, or any other botanical. There were zero deaths from creatine, blue-green algae, glucosamine, chondroitin, melatonin, or any homeopathic remedies.
Furthermore, there were zero deaths in 2008 from any dietary mineral supplement. This means there were no fatalities from calcium, magnesium, chromium, zinc, colloidal silver, selenium, iron, or multimineral supplements. Two children died as a result of medical use of the antacid sodium bicarbonate. The other “Electrolyte and Mineral” category death was due to a man accidentally drinking sodium hydroxide, a highly toxic degreaser and drain-opener.
No man, woman or child died from nutritional supplements. Period.
61 poison centers provide coast-to-coast data for the U.S. National Poison Data System, which is then reviewed by 29 medical and clinical toxicologists. NPDS, the authors write, is “one of the few real-time national surveillance systems in existence, providing a model public health surveillance system for all types of exposures, public health event identification, resilience response and situational awareness tracking.”
Over half of the U.S. population takes daily nutritional supplements. Even if each of those people took only one single tablet daily, that makes 154,000,000 individual doses per day, for a total of over 56 billion doses annually. Since many persons take more than just one vitamin or mineral tablet, actual consumption is considerably higher, and the safety of nutritional supplements is all the more remarkable.
Hypersensitivity, Not Toxicity
Vitamin D hypersensitivity syndromes are often mistaken for vitamin D toxicity, as they cause hypercalcemia. The most common is primary hyperparathyroidism although some cases of “primary” hyperparathyroidism are actually secondary to Vitamin D deficiency. Patients with hyperparathyroidism should only take vitamin D under the care of a knowledgeable endocrinologist. Granulomatous diseases such as sarcoidosis, granulomatous TB, and some cancers can also cause Vitamin D hypersensitivity, as the granuloma or the tumor may make excessive amounts of activated Vitamin D, thus raising serum calcium. These patients should not take vitamin D except when under the care of a knowledgeable physician.
Other syndromes occur when abnormal tissue subverts the kidney’s normal regulation of endocrine calcitriol production. Aberrant tissues, usually granulomatous, convert 25(OH)D into calcitriol causing high blood calcium. The most common such conditions are sarcoidosis, oat cell carcinoma of the lung, and non-Hodgkin’s lymphoma but other illnesses can cause the syndrome and they can occur while the patient’s 25(OH)D levels are normal, or even low. For that reason, while rare, it is advisable to seek a knowledgeable physician’s care when repleting your vitamin D system, especially if you are older, have sarcoidosis, cancer, or other granulomatous diseases. In such high-risk patients, periodic monitoring of 25(OH)D levels and serum calcium will alert the physician to the need to do more tests—such as calcitriol or PTH—and take further action.
It seems clear that restoring physiological serum levels of 25(OH)D will benefit many more patients than it will hurt. Although there are many medical professionals that warn against too much vitamin D, they fail to communicate how rare these instances actually are. In fact, living in America today while worrying about vitamin D toxicity is like dying of thirst in the desert while worrying about drowning.
The implication of the accumulating evidence that is mounting on the ever expanding benefits of vitamin D adequacy will change all of epidemiology as we now know it. Every fact we know, every statistic we know must be prefaced by whether or not the population under review was vitamin D deficient or not.