Taking vitamin D supplements may lower the risk of death from any cause, according to a meta-analysis in the Sept. 10 issue of Archives of Internal Medicine (2007;167(16):1730-37). After reviewing 18 randomized controlled trials of vitamin D supplementation, with a total of 57,311 participants, the researchers found 4,777 of the participants died during the average follow-up period of 5.7 years. Those taking vitamin D had a 7-percent lower risk of death than those who did not, and their blood levels of vitamin D were 1.4- to 5.2- fold higher than those people not taking supplements. The authors said it was unclear how supplementation could decrease all-cause mortality, though they suggested it may inhibit carcinogenesis or boost immune function.
A related Archives editorial (2007;167(16) :1709-10) by Edward Giovannucci, M.D., Harvard School of Public Health, said the meta-analysis increases the evidence base concerning vitamin D’s benefits to human health. “Research on vitamin D should be continued to clearly elucidate the specific benefits and optimal intakes and levels of vitamin D,” Giovannucci wrote. “Nonetheless, based on the total body of evidence of health conditions associated with vitamin D deficiency, abetted with the results from this meta-analysis, a more proactive at titude to identify, prevent and treat vitamin D deficiency should be part of standard medical care. From a broader public health perspective, the roles of moderate sun exposure, food fortification with vitamin D and higher-dose vitamin D supplements for adults need to be debated.”