Oral vitamin D supplements at a dose of at least 400
international units per day are associated with a reduced risk
of bone fractures in older adults, according to results of a
meta-analysis published in the March 23 issue of Archives of
Internal Medicine, one of the JAMA/Archives journals. "The anti-
fracture benefits of vitamin D have been questioned by several
recent trials, leading to uncertainty among patients and
physicians regarding recommendations for vitamin D
supplementation," the authors write as background information in
the article. "Factors that may obscure a benefit of vitamin D
are low adherence to treatment, low dose of vitamin D or the use
of less potent ergocalciferol (vitamin D2)." Heike A. Bischoff-
Ferrari, Dr.P.H., of the University of Zurich, University
Hospital, Zurich, Switzerland, and colleagues performed a meta-
analysis on 12 previously published clinical trials of oral
vitamin D supplements among adults age 65 or older. These
double-blind randomized controlled trials involved 42,279