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nfluence of season and latitude on the cutaneous synthesis of vitamin D3: exposure to winter sunlight in Boston and Edmonton will not promote vitamin D3 synthesis in human skin. Webb AR, Kline L, Holick MF. J Clin Endocrinol Metab. 1988 Aug;67(2):373-8. PMID: 2839537 doi:10.1210/jcem-67-2-373 These results quantify the dramatic influence of changes in solar UVB radiation on cutaneous vitamin D3 synthesis and indicate the latitudinal increase in the length of the "vitamin D winter" during which dietary supplementation of the vitamin may be advisable.

"June 29, 2009 | Shelley Wood Boston, MA - A massive, National Institutes of Health-sponsored study looking at whether vitamin-D and/or omega-3 fatty-acid supplementation can reduce the risk of developing heart disease, stroke, or cancer will get under way in January 2010, according to a website for the study. Drs JoAnn Manson and Julie Buring (Harvard Medical School/ Brigham and Women's Hospital, Boston, MA) will head up the Vitamin D and Omega-3 Trial (VITAL). The study is aiming to enroll 20 000 men and women, one-quarter of whom will be black. According to a Brigham and Women's Hospital press release, the study is intentionally aiming to illuminate a potential racial and ethnic disparity hypothesized to be linked to vitamin D [1]. "African Americans have a higher risk of vitamin-D deficiency as well as a greater frequency of diabetes, hypertension, and certain types of cancer," a press release notes. For VITAL, women need to be over age 65 to enter the study; men need to be over age 60. Study participants will be randomized to one of four groups: daily vitamin D (2000 IU) and fish oil (1 g); daily vitamin D and fish-oil placebo; daily vitamin-D placebo and fish oil; or daily vitamin-D placebo and fish-oil placebo. The trial will run for five years and is expected to cost US $20 million."

An evaluation of the relative contributions of exposure to sunlight and of diet to the circulating concentrations of 25-hydroxyvitamin D in an elderly nursing home population in Boston. Webb AR, Pilbeam C, Hanafin N, Holick MF. Am J Clin Nutr. 1990 Jun;51(6):1075-81. PMID: 2349922

The Vitamin D Pandemic and its Health Consequences\nPresented by Michael Holick, PhD, MD, Professor of medicine, physiology and biophysics and director of the General Clinical Research Center at Boston University Medical Center\nKeynote address at the opening ceremony of the 34th European Symposium on Calcified Tissues, Copenhagen 5 May, 2007\n

"DALLAS, Jan. 8 - The same vitamin D deficiency that can result in weak bones now has been associated with an increased risk of cardiovascular disease, Framingham Heart Study researchers report in Circulation: Journal of the American Heart Association. "Vitamin D deficiency is associated with increased cardiovascular risk, above and beyond established cardiovascular risk factors," said Thomas J. Wang, M.D., assistant professor of medicine at Harvard Medical School in Boston, Mass. "The higher risk associated with vitamin D deficiency was particularly evident among individuals with high blood pressure." In a study of 1,739 offspring from Framingham Heart Study participants (average age 59, all Caucasian), researchers found that those with blood levels of vitamin D below15 nanograms per milliliter (ng/mL) had twice the risk of a cardiovascular event such as a heart attack, heart failure or stroke in the next five years compared to those with higher levels of vitamin D."