We ve often heard about the miraculous properties of certain vitamins and supplements, and vitamin D is quite commonly listed among them. But a new report from the U.S. Preventive Services Task Force, published in the Annals of Internal Medicine, finds little evidence to support those claims; it concludes that there is a paucity of evidence to suggest that vitamin D plays any role in preventing cancer or lowering the risk of heart disease.
However, upon the Task Force s review of 19 clinical trials and 28 observational studies, one positive effect of vitamin D was noted: The new report supports previous findings showing that vitamin D, in combination with calcium, reduces the risk of bone fracture among older individuals. Currently, the recommended daily allowance for older adults 51 and older is 600 to 800 international units of the vitamin. Unfortunately, some people mistakenly believe that ingesting more will result in greater health effects, and they end up consuming excessive amounts of vitamin D.
ACSH s Dr. Ruth Kava reminds us, however, that going overboard with vitamin D can actually lead to adverse health effects, including kidney stones and dangerously elevated levels of serum calcium, so it s better to stay within the recommended guidelines.