Study finds no clear health benefit of vitamin D
While vitamin D is essential for regulating our absorption of calcium and phosphorus in our bones, many health professionals, as well as two new studies, have reservations about other potential health benefits of vitamin D.
The first study was conducted by researchers from the US, UK and Europe. The team analyzed data from observational studies and clinical trials that looked at health outcomes linked to vitamin D levels. Although the researchers identified 137 different health outcomes associated with vitamin D levels, they found that only 10 of these outcomes had been comprehensively tested in trials, and only one outcome - that an infant's birth weight is linked to a mother's vitamin D levels in late pregnancy - had enough evidence to deem it a “benefit.” Additionally, the research team found no evidence that vitamin D supplementation had any benefits for osteoporosis or helped prevent falls - a finding that contradicts previous research.
In the second study, researchers led by the University of Cambridge in the UK and the Erasmus Medical Centre in the Netherlands analyzed observational cohorts and randomized controlled trials that looked at the association between vitamin D and death from cardiovascular disease and cancer, among other conditions. In the randomized controlled trials, follow-up varied from 3 to 7 years. The research team found that of the individuals who took vitamin D supplements, 2,527 deaths occurred, compared with 2,587 deaths in control groups. They also found that when vitamin D2 supplements were taken alone, there was no reduction in participants' risk of death, but when vitamin D3 supplements were taken alone, participants had an 11% reduction in the risk of death.
Despite these results, the research team notes that since the trials in this review involved elderly populations, in which death is commonly a result of coexisting conditions, further research is needed to determine the correct dosage of vitamin D supplements that should be taken, duration and safety of the supplements.
Overall, the researchers feel that until there’s concrete evidence of the health benefits of vitamin D, doctors shouldn’t recommend vitamin D supplementation unless a patient has bone disease or a related condition.