Vitamin D and Physical Function in Sedentary Older Men

Objectives: To determine the effectiveness of vitamin D supplementation in preventing decline in physical function in older men.

Design: Randomized, double-blind, placebo-controlled clinical trial.

Setting: Single-center study conducted at a Veterans Affairs Healthcare System.

Participants: Sedentary men aged 65 to 90 (mean 72.4 ± 6.8) with baseline 25-hydroxyvitamin D (25(OH)D levels of less than 30 ng/mL and Short Physical Performance Battery (SPPB) test scores of 9 or less (N = 130).

Intervention: Daily capsule containing cholecalciferol 4,000 IU daily or placebo for 9 months.

Measurements: Main outcomes were SPPB score and gait speed.

Results: After the intervention, serum 25(OH)D increased from 23.1 ± 5.0 ng/mL to 46.2 ± 12.7 ng/mL in the cholecalciferol group and from 22.5 ± 5.3 ng/mL to 24.0 ± 7.2 ng/mL in the placebo group. At study end, improvements in SPPB score and gait speed were not significantly greater in men receiving cholecalciferol than in those receiving placebo. No differences were found in adverse events or numbers of falls.

Conclusion: Daily cholecalciferol 4,000 IU for 9 months resulted in significant increases in 25(OH)D concentrations, but achieving these higher levels did not result in improvements in SPPB score or gait speed. These data do not support prescribing vitamin D supplements to older sedentary men to prevent physical function decline.