Effect of Vitamin D3 and calcium carbonate supplementation on muscle strength in postmenopausal women living with HIV.

BACKGROUND Both falls and fractures are increased in older persons living with HIV (PLWH). Low serum total 25-hydroxyvitamin D (25OHD) levels have been associated with falls, fractures and poor muscle strength. We hypothesized that vitamin D (VitD) supplementation would improve muscle strength in postmenopausal PLWH. METHODS In a 12-month prospective, randomized, double-blind, study of 69 black and Hispanic postmenopausal PLWH on antiretroviral therapy with 25OHD ≥10 ng/mL and < 32 ng/mL, we investigated the effects of daily Low (1000 IU; n=31) and Moderate (3000 IU; n=38) cholecalciferol doses on lean mass and strength. Change in lean body mass was assessed by DXA and isometric and isokinetic muscle strength in the dominant lower extremity was assessed using the Biodex System 4 Pro. RESULTS Mean age was 56+5 years, median CD4 count 722 cells/mm3 and 74% had HIV RNA<50 copies/ml. Serum 25OHD did not differ at baseline, but was higher in the Moderate than Low VitD group at 6 and 12 months. In the both groups, there were significant increases in lower extremity isokinetic torque, work and power at 12 months, with no change in lean mass. CONCLUSION VitD supplementation was associated with a modest increase in lower extremity strength in postmenopausal PLWH, without a concomitant increase in muscle mass. Magnitude of increase in strength were similar with 3000 IU and 1000 IU daily. Future and larger studies will be required to determine the optimal dose of VitD to improve muscle strength and to determine whether supplementation reduces the risk of falls and fractures in PLWH.