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New Research on Vitamin D: A Real Missing Link in Our Nutrition

(Courtney Carpenter, MS) -- Vitamin D, the "sunshine vitamin," is getting new respect within the professional medical and nutrition communities due to research that has come to fruition over the last decade. Although the function of vitamin D as a hormone rather than a simple vitamin had already been widely recognized, new research defines vitamin D metabolites as actors on over 1000 different gene products. These influence a diverse range of physical and mental health problems from autism to cancer.

The public health implications of vitamin D deficiency are as stunning as they are vast. No one is proposing that vitamin D is a panacea, however it seems to provide part of the sturdy framework for our physical and mental well being. Almost all of us are at risk unless we expose ourselves to just enough sunlight, specifically UV-B radiation, year round to make our skin pink consistently.  Breast milk and formula have too little vitamin D and low levels during pregnancy have been linked to aberrations in neural development, so our needs begin before birth. Dark skin or tan easily? These evolutionary protections from making too much vitamin D on our skin put us at risk in our modern world. Fair complexion and careful to wear sunscreen? Many researchers suggest that rates of depression and autism have skyrocketed during the time that sunscreens have been widely promoted and used. Finally, being over forty carries its own risk, because as we age we lose some of our ability to digest and absorb all nutrients and we also lose some of the ability to make vitamin D on our skin. Another risk factor revolves around how vitamin D receptors on virtually all our cells respond to vitamin D. The vitamin D receptor (VDR) gene governs this and everyone's receptors are not equally receptive, which happens because of variant genetic expression also known as polymorphism.

A quick search of the National Institutes of Health National Library of Medicine site pubmed.gov generates a list of 2997 articles published in peer reviewed journals on vitamin D in humans in 2008 alone! Some highlights include vitamin D status and its impact on breast cancer, colon cancer, prostate cancer and lung cancer. Vitamin D levels also affect the cardiovascular system. WebMD quotes James H. O'Keefe, MD, board certified cardiologist at the Mid America Heart Institute in Kansas City, Missouri: "Vitamin D deficiency is an unrecognized, emerging cardiovascular risk factor, which should be screened for and treated. Vitamin D is easy to assess, and supplementation is simple, safe and inexpensive." (www.webmd.com/heart-disease/news/20081201/too-little-vitamin-d-puts-heart-at-risk) Research continues on vitamin D and bone health, autoimmune disease and diabetes, in addition to every other health problem I have mentioned. Researchers allied with the Vitamin D Council propose the existence of “vitamin D deficiency syndrome (VDDS)” in individuals with blood levels of vitamin D less than 25 ng/mL who have two or more of these conditions: osteoporosis, heart disease, hypertension, autoimmune disease, certain cancers, depression, chronic fatigue, or chronic pain (www.vitamindcouncil.org/vdds.shtml).

Doctors can and should order routine vitamin D blood tests for all of their patients. Individuals should request a vitamin D blood test at their next visit, if their doctor is not forthcoming.    The only test indicative of true vitamin D status is for the intermediate metabolite 25-hydroxy (-OH) vitamin D.  According to several local physicians with whom I have spoken, not one of their patients has been in the optimal range of 50 to 80 nanograms per milliliter (ng/ml) initially. Most have been below the reference range, which begins at 32 and ends at 100(ng/ml). They are all recommending supplementation. I advise all my clients to specifically inquire about their vitamin D number, since "normal" values are often equated with optimal status and this simply is not true. In addition, I have observed that doctors are  recommending only 1000 IU's per day of vitamin D3 (cholecalciferol), even when patients are below the reference range, or they are writing prescriptions for vitamin D at 50,000 IU's in a once weekly dose, both of which are inadequate. Prescription vitamin D is only available as vitamin D2 (ergocalciferol), known to be inferior to D3. Raising vitamin D blood levels into the optimal range from below the reference range routinely requires a daily dose of 6000 to 8000 IU’s of cholecalciferol (D3) for two to three months. Staying in the optimal range requires a minimum of 1000 to 2000 IU’s per day, with potentially increased need during the winter months or for those in higher risk categories. Vegetarians should note that commercial D3 is largely derived from lanolin gleaned from sheep’s wool, rather than from fish oil. Vegans should be advised that supplementing with D2, derived from irradiating fungus, may require twice the amount of D3 proposed to make up for its inadequacies, but it may also be more toxic because it does not exist naturally in the human body.

Unfortunately, not all medical professionals are equally aware of this new body of research or they remain so skeptical of the value of micronutrients that they consistently undervalue new positive research, while assigning greater value to research that has been eclipsed. According to John J. Canell, MD, Executive Director of the Vitamin D Council three studies published between 1984 and 2001 have been given more credibility than they deserve and have thereby inhibited recognition of critically low vitamin D status in individuals around the globe. The Vitamin D Council asserts that new data suggesting higher safe levels of vitamin D was rejected by scientific advisors to the federal government in favor of a single smaller study where adverse effects were seen with lower reported levels, even after the original data points were called into question. The two other studies cited include technical and analytical errors and one clear case of misdiagnosis. (See www.vitamindcouncil.org/worst_science.shtml)

Regardless of whether you have ever recommended or taken a vitamin supplement, please consider how dramatically knowledge about Vitamin D has increased over the last decade and become curious for yourself and for those you care for. No one has ever benefited from remaining uninformed!