As vitamin D gains more attention, the American Academy of Dermatology recently amended its position on this vital prohormone, saying that it should be obtained from a healthy diet and supplements, not UV exposure.

The Academy also recommends that physicians should provide information on options for obtaining sufficient dietary or supplementary sources of vitamin D to their patients who are at high risk for vitamin D insufficiency.

Many epidemiological studies suggest an association between low serum vitamin D levels and increased risk of certain types of cancers, neurologic disease, autoimmune disease and cardiovascular disease (CVD).

The National Academy of Sciences Institute of Medicine (IOM) is currently reviewing the recommended adequate intake levels, and these guidelines may be revised upward due to evolving research on the increasing clinical benefit of vitamin D.

A higher dose of vitamin D intake, through a combination of diet and supplementation, may be necessary for individuals with known risk factors for vitamin D insufficiency (e.g. dark skin individuals, elderly persons, photosensitive individuals, people with limited sun exposure, obese individuals or those with fat malabsorption).

A recent symposium on nutrition and heart disease also addressed vitamin D and its association with increased risk of CVD, including hypertension, heart failure and ischemic heart disease. Information from the symposium is summarized in the July issue of the American Journal of the Medical Sciences.

In one report, Suzanne Judd, PhD, from Emory University School of Medicine in Atlanta, GA, notes that very few prospective clinical studies have been conducted to examine the effect of vitamin D supplementation on cardiovascular outcomes. The mechanism for how vitamin D may improve CVD outcomes remains obscure; however, potential hypotheses include the down regulation of the renin-angiotensin-aldosterone system, direct effects on the heart, and vasculature or improvement of glycemic control.

The National Institutes of Health Office of Dietary Supplements, Bethesda, MD, is also intent on supporting a number of initiatives to advance the evidence base on vitamin D. According to Rebecca Costello, PhD, these initiatives include an evidence-based review on the relationship of vitamin D and calcium intakes to nutrient status indicators and health outcomes; developing and validating analytical methods for measuring vitamin D in biological fluids and foods; support for continued collection of vitamin D status indicators through the National Health and Nutrition Examination Survey; and funding for National Institutes of Health grants on vitamin D and related health outcomes. Taken together, these programs address research gaps and needs to further the science and exploration of the role of vitamin D in health.