A systematic review on the effect of vitamin D supplementation in bone mineral density and muscle strength in postmenopausal women

Background: The globally prevalent vitamin D deficiency has adverse health consequences. Improving vitamin D deficiency through supplementation of vitamin D through diet or drugs has health benefits, including bone health and muscle strength in the general population. Objectives: This systematic review investigated the effect of vitamin D supplementation on bone mineral density (BMD) and muscle strength in postmenopausal women. Methods: Electronic databases, including Cochrane and PubMed, were systematically searched for randomized controlled trials (RCTs) with vitamin D intervention from 2010 to 2025. The outcomes were BMD and muscle strength. The quality of evidence was assessed using Cochrane risk of bias (RoB2). Results: Fifteen RCTs involving 3054 postmenopausal women were evaluated. Vitamin D2 doses (1000 IU/day–40,000 IU/week) and vitamin D3 doses (400 IU/day–150,000 IU/3 months) were administered. Fortified foods included milk with 120 IU/100 mL or 15 μg of vitamin D. Supplementation significantly increased vitamin D levels, improved muscle function (chair rising test, hip extensor/adductor strength), and increased BMD at the femoral neck (FN) but not the lumbar spine. Conclusions: Vitamin D2/D3 supplementation or vitamin D fortification increased vitamin D levels in postmenopausal women. There was a positive effect on lumbar and FN BMD, as well as muscle strength, but further RCTs are needed for conclusive evidence.