Health Benefits of Vitamin D
Vitamin D is actually a misnomer for the steroid compound calciferol, of which there exist two forms in nature: D2 (ergocalciferol) and D3 (cholcalciferal). Vitamin D2 is found in vegetarian sources of food, whereas the latter D3 form is synthesized on the skin in response to exposure to ultra-violet rays and is found in fish liver oil and certain dairy and meat products. There is also a synthetic form known as Vitamin D5. Cholcalciferol or Vitamin D3 is considered the most natural of the three and is readily absorbed and utilized by our cells, thus being the preferred form of this vital compound.
Of the mere 30,000 genes in the human body, Vitamin D has been shown to influence 3,000 or 10%. Studies have linked the steroid to numerous diseases ranging from cancer and autism to heart disease and arthritis. Rightfully placed in the hot seat of much recent talk in the healthcare community, Vitamin D has many important functions, the most well-known of which is maintenance of bone health. But the benefits of this hormone extend much farther and are now finally claiming their proper attention as new studies are published daily.
So what does Vitamin D do?
Vitamin D works synergistically with calcitonin and parathyroid hormone (PTH) to maintain bone health. Together they regulate the absorption of calcium and phosphorous from the small intestine according to our needs. They can also regulate these blood calcium levels by signaling the kidneys to release or withhold calcium in the urine. Additionally, Vitamin D stimulates osteoclast activity when necessary and assists with normal calcification of bone. It is crucial for normal growth and is especially important for the normal growth and development of bones and teeth in children. Severe deficiency of Vitamin D in children can cause rickets, a bone-deforming disease, and osteomalacia meaning "soft bones" in adults. Osteomalecia is similar to osteoporosis, another disease on the bones linked to a Vitamin D deficiency. With both, bones become weak and prone to fractures.
Vitamin D has other roles in the body, including modulation of cell growth, neuromuscular and immune function, and reduction of inflammation. Many genes encoding proteins that regulate cell proliferation, differentiation, and apoptosis are modulated in part by vitamin D. By keeping tabs on cellular growth, Vitamin D aids in the prevention of many cancers, which are discussed in more detail later in this article.
Along with Vitamin K, Vitamin D helps to maintain healthy blood vessels and assists with blood clotting and the inflammatory response when these are breached (by injury).
Vitamin D is specifically associated with autoimmune thyroid disease (AITD) and has been shown to be extremely beneficial to patients suffering with thyroid disorders of various degrees. Its method of action with regard to the thyroid is balancing the cell-mediated and humeral arms of the immune system through strong influence of T-regulatory (Th3) cells.
"Mary Shomon: Why do you feel vitamin D is so important to thyroid sufferers?
"Richard Shames, MD: This particular vitamin is so crucial to thyroid function that its status has now been elevated by researchers to co-hormone. We now know that the variability of thyroid to work or not work in your body is dependent upon the presence of Vitamin D, making it not just of benefit, but absolutely essential."
Taken directly from a recent paper released by the NCBI: Vitamin D functions are not limited to skeletal health benefits and may extend to preservation of insulin secretion and insulin sensitivity. Achieving Vitamin D sufficiency has shown beneficial in patients with pre-diabetes and reduces risk of the disease.
Vitamin D and Cancer
More than 200 epidemiological studies have linked Vitamin D deficiency to 16 types of cancer. A study by Dr. William Grant, Ph.D., internationally recognized research scientist and vitamin D expert, found that about 30 percent of cancer deaths — which amounts to 2 million worldwide and 200,000 in the United States — could be prevented each year with higher levels of vitamin D. The protective effects of Vitamin D are attributed to several key physiological functions: increasing the self-destruction of mutated cells (which, if allowed to replicate, could lead to cancer), reducing the spread and reproduction of cancer cells, causing cells to become differentiated (cancer cells often lack differentiation) and reducing the growth of new blood vessels from pre-existing ones, which is a step in the transition of dormant tumors turning cancerous.
Vitamin D vs. Colds & Flus
Vitamin D regulates the expression of certain immunological genes that govern your body's defense system against colds and flus. A 2010 study showed that children taking 1200 IU of Vitamin D3 per day were 42% less likely to contract influenza, compared to children taking a placebo. A recent study put out by the Journal of the American Medical Association denounced Vitamin D supplementation, claiming that it is completely useless against colds, upper respiratory infections, and influenza since there was only a 10% reduction in the rate of infection from experimental to control group. Dr. Cannell, founder of the Vitamin D Council, published a report soon after the release of JAMA's, however, explaining that these conclusions are a gross misinterpretation of the data generated by the study.
All but 13 of the over 900 participants started with and kept blood serum levels above 20ng/ml. Through his extensive work on the subject, Dr. Cannell has found that a blood serum level of 20ng/ml or higher is all that's required to lower the rate of respiratory infection. Until this level reaches between 70 and 100ng/ml (therapeutic), the incremental increases are not associated with any significant increases in bodily immune response, although levels of 50-70ng/ml are considered optimal for other benefits to the human body. Consequently, a general statement denouncing the beneficial properties of Vitamin D is both uncalled for and invalid with regard to these results.
In conclusion, maintenance of optimal Vitamin D blood serum levels are fundamental to warding off the cold and flu, however megadosing has not been shown to be very effective in boosting immune function; rather, therapeutic dosing is more beneficial for chronic diseases such as cancer and CVD. Avoiding Vitamin D deficiency is the number one thing one can do for flu prevention.
To read more about this topic and to access Dr. Cannell and other Vitamin D experts' work, I highly recommend exploring the links provided at the end of this article.
Vitamin D Deficiency – How Do We Level?
In a study reported by The New England Journal of Medicine, there are indications that Vitamin D deficiency is much more widespread than previously thought, especially in older adults. In a group of people of whom few had risk factors for Vitamin D deficiency, 57% were found to have below-normal levels. 67% of those reporting intake below the RDI had deficiencies categorized as moderate to severe. More recent postulations estimate that 85% of the American public is deficient in vitamin D and over 95% of African American or deeply pigmented individuals are deficient. During winter months, average serum levels in the US are between 15-18ng/ml – known to be a severe deficiency state.
Where you live in relation to the equator has a severe impact on your risk for Vitamin D deficiency, as well as your risk for developing cancer – a correlation well-established by numerous observational studies. According to Dr. William Grant, one of the top vitamin D researchers in the world, the cancer rate in Iceland is 90 per 100,000 people per year. Those in the tropics, meanwhile, have rates of 25 per 100,000. And regardless of location, your risk changes relative to the time of the year and the amount of sunshine you receive in a day.
Am I Vitamin D Deficient? How Can I address A Deficiency?
Severe deficiency of Vitamin D can cause rickets in children and osteomalecia in adults. Lesser degrees of deficiency may be characterized by loss of appetite, a burning sensation in the mouth and throat, diarrhea, insomnia, visual problems and weight loss. Most people suffering from Vitamin D deficiency however, do not experience many – or any – acute symptoms. Rather, the symptoms are an effect on long-term health, elevated risk of developing serious and chronic diseases, and having a lowered immune system among other suppressed body functions.
The best way to test for Vitamin D deficiency is by a blood test called 25(OH)D, also called 25-hydroxyvitamin D. You can order this test with your primary care physician.
Since such a high percentage of our population is deficient according to researchers, chances are you are deficient – especially if you live in the upper third of the continental US or an area of the world along similar latitude. The optimal way to prevent Vitamin D deficiency is ensuring adequate sunlight exposure on your bare skin. Be cautious however, that you do not reach the point of sunburn, as this can have serious negative impacts on your health and promote skin cancer. Use the appropriate amount of non-chemical 30SPF sunblock for your skin tone, paying particular care to your face and shoulders.
An equilibrium occurs in white skin within 20 minutes of ultraviolet exposure, at which point further increases in vitamin D are not possible, because the ultraviolet light will actually start to degrade the vitamin D. It can take 3-6 times longer for darker pigmented skin to reach the equilibrium concentration of skin pre vitamin D. However, skin pigmentation does not affect the amount of vitamin D that can be obtained through sunshine exposure.
Oral supplementation of Vitamin D3 is recommended during winter months and for those with a determined deficiency.
At Matrix Nutrients, we recommend a maintenance dose of 1000-2000IU daily along with a diet that emphasizes Vitamin D-rich foods. Cod liver oil is an ideal source for food-based Vitamin D and A.
Our Whole Food Matrix Vitamin D supplement, provides 1000IU per tablet. Our unique formula provides the most absorbable supplemental form of Vitamin D3 available on the market today. As with all of our Whole-Food Matrix Supplements, Vitamin D (cholcalciferol, D3) is bound to protein transporters that allow our cell receptors to recognize, uptake and utilize it properly.
With a blood test-determined Vitamin D deficiency, your specific supplemental dosage may need to be increased significantly – as much as tenfold or more! However, without the proper testing we caution such megadosing as Vitamin D is a fat-soluble vitamin with potential for toxicity at such levels if there is no need for it.
Buy Whole Food-Matrix Vitamin D here.
Additional Vitamin D Resources
Alvarez, Jessica A., and Ambika Ashraf. "Role of Vitamin D in Insulin Secretion and Insulin Sensitivity for Glucose Homeostasis." International Journal of Endocrinology 2010 (2010): 1-18. Print.
Balch, Phyllis A. "Vitamin D." Prescription for Nutritional Healing: The A to Z Guide to Supplements. New York: Avery, 2002. 44-46. Print.
Kresser, Chris. "The Role of Vitamin D Deficiency in Thyroid Disorders." Chris Kresser L. Ac. Medicine for the 21st Century, 4 Aug. 2010. Web. 23 Oct. 2012..
Mercola, Joseph. "Will Boosting Your Vitamin D Levels Help Prevent Colds or Not?" Take Control of Your Health. Mercola.com, 17 Oct. 2012. Web. 21 Oct. 2012..
Shohom, Mary. "Why Is Vitamin D So Important to Thyroid Patients?" Thyroid Disease. About.com, 30 Sept. 2010. Web. 23 Oct. 2012..
Thompson, Janice, and Melinda Manore. "A Profile of Nutrients That Maintain Bone Health." Nutrition: An Applied Approach. San Francisco: Pearson/Benjamin Cummings, 2012. 302-08. Print.
Various Professional Authors. "Vitamin D." Office of Dietary Supplements. National Institutes of Health, 24 June 2011. Web. 22 Oct. 2012..