Effects of a long-term vitamin D and calcium supplementation on falls and parameters of muscle function in community-dwelling older individuals

In 242 community-dwelling seniors, supplementation with either 1000 mg of calcium or 1000 mg of calcium plus vitamin D resulted in a decrease in the number of subjects with first falls of 27% at month 12 and 39% at month 20. Additionally, parameters of muscle function improved significantly. The efficacy of vitamin D and calcium supplementation on risk of falling in the elderly is discussed controversially. Randomized controlled trials using falls as primary outcome are needed. We investigated long-term effects of calcium and vitamin D on falls and parameters of muscle function in community-dwelling elderly women and men. Our study population consisted of 242 individuals recruited by advertisements and mailing lists (mean [ +/- SD] age, 77 +/- 4 years). All serum 25-hydroxyvitamin D (25[OH]D) levels were below 78 nmol/l. Individuals received in a double blinded fashion either 1000 mg of calcium or 1000 mg of calcium plus 800 IU of vitamin D per day over a treatment period of 12 months, which was followed by a treatment-free but still blinded observation period of 8 months. Falls were documented using diaries. The study took place in Bad Pyrmont, Germany (latitude 52A degrees) and Graz, Austria (latitude 46A degrees). Compared to calcium mono, supplementation with calcium plus vitamin D resulted in a significant decrease in the number of subjects with first falls of 27% at month 12 (RR = 0.73; CI = 0.54-0.96) and 39% at month 20 (RR = 0.61; CI = 0.34-0.76). Concerning secondary endpoints, we observed significant improvements in quadriceps strength of 8%, a decrease in body sway of 28%, and a decrease in time needed to perform the TUG test of 11%. Combined calcium and vitamin D supplementation proved superior to calcium alone in reducing the number of falls and improving muscle function in community-dwelling older individuals.