Low-Dose Vitamin D Prevents Muscular Atrophy and Reduces Falls and Hip Fractures in Women after Stroke: A Randomized Controlled Trial

OBJECTIVE Vitamin D supplementation is suggested to reduce the risk of falls among ambulatory or institutionalized elderly subjects. The present study was undertaken to address the reduced risk of falls and hip fractures in patients with long-standing stroke by vitamin D supplementation. METHODS Ninety-six elderly women with poststroke hemiplegia were followed for two years. Patients were randomly assigned to one of the two groups, and 48 patients received 1,000 IU ergocalciferol daily, and the remaining 48 received placebo. The number of falls per person and incidence of hip fractures were compared between the two groups. Strength and tissue ATPase of skeletal muscles on the nonparetic side were assessed before and after the study. RESULTS At baseline, serum 25-hydroxyvitamin D levels were in the deficient range (<10 ng/ml) in all patients; and vitamin D treatment enhanced serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D levels. Vitamin D treatment accounted for a 59% reduction in falls (95% CI, 28-81%; p = 0.003). There were increases in the relative number and size of type II muscle fibers and improved muscle strength in the vitamin D-treated group. Hip fractures occurred in 4 of 48 placebo group and 0 in 48 vitamin D2 group during the 2-year study period (log-rank, p = 0.049). CONCLUSION Vitamin D may increase muscle strength by improving atrophy of type II muscle fibers, which may lead to decreased falls and hip fractures.