Vitamin D Supplementation and Increased Risk of Falling: A Cautionary Tale of Vitamin Supplements Retold.

摘要: The randomized clinical trial (RCT) by Bischoff-Ferrari et al1 in this issue of JAMA Internal Medicine shows that vitamin D supplementation is associated with the risk falls. Two “high” doses (60 000 IU D3 per month or 24 plus 300 mg calcifediol month) achieved a serum 25-hydroxyvitamin (25[OH]D) level 30 ng/mL 80% participants, has been recommended as best for reducing fractures and other health benefits (to convert 25[OH]D to nanomoles liter, multiply 2.496).2,3 However, compared dose 24000 (equivalent 800 day), higher had no effect on lower extremity physical performance increased A previous RCT4 women same age showed 500000 year 25(OH)D levels at least most participants but significantly falls 15% 26%. theoretical possibility raised periodic administration high accounts fractures.5 That hypothesis should be tested placebo-controlled trials showing daily 2000 IU, example, reaching reduces fractures. issue1 placebo group and, therefore, could not test effects day. recent placebocontrolled Uusi-Rasi al6 found an day supplement function injurious falls, whereas exercise program reduced about half. Another postmenopausal 75 years younger.7 It uncertain whether any communitydwelling older adults. Previous meta-analyses RCTs differed supplements reduce falls8-11 fractures8,12-14 community-dwelling elderly individuals. In contrast meta-analyses15-17 have shown 1200 calcium hip fracture mortality patients dwelling institutions. These receive supplements. Clinicians recommend putative benefits. There evidence frommeta-analyses ofRCTs vitaminDsupplementation cardiovascular disease cancer.13,18 addition, trial19 1000 IUof vitaminDper day, without calcium, did decrease coloncanceror recurrent adenomas thosewithahistoryof colon adenomas. story seems following familiar pattern observed antioxidant vitamins. Enthusiasm coupled belief “vitamins” are inherently safe reinforced observational studies showing, essentially, healthy people levels. Then meta-analyses20 proved fact increase (β-carotene, E), (vitamin A, C). strategy achieve established may falling. Until approach supported updated meta-analyses, it would prudent follow recommendations21 from Institute (IOM) 70 total intake routine measurement get intakes vitamins balanced diet foods naturally contain what manufactured into