Based on evidence from 40 randomized, controlled studies, a recent study by University of Auckland scientists has reportedly concluded that vitamin D supplements provide little to no health benefit and do not prevent heart attack, stroke, cancer, or bone fractures in the general population by more than 15 percent. Mark Bolland, et al., “The effect of vitamin D supplementation on skeletal, vascular, or cancer outcomes: a trial sequential meta-analysis,” The Lancet Diabetes & Endocrinology, January 24, 2014.
Noting that previous observational studies showed that vitamin D deficiency was strongly associated with poor health and early death, researchers have concluded that this association is not causal and that supplementation is not likely to have any benefit. “The take-away message is that there is little justification currently for prescribing vitamin D to prevent heart attack, stroke, cancer, or fractures in otherwise-healthy people living in the community,” lead author Mark Bolland reportedly said. “The only benefit from vitamin D was in reducing hip-fracture risk in elderly women living in residential care; in those 2 studies, the vitamin D supplements were given with calcium, at a dose of 800 IU/day … In terms of harm, there was uncertainty as to whether vitamin D without calcium might increase the risk of hip fracture,” he added. See Medscape.com, January 24, 2014.