Vitamin D: Update Bone and Muscle Effects

Vitamin D modulates fracture risk in 2 ways: by decreasing falls and increasing bone density. Two most recent meta-analyses of double-blind randomized controlled trials came to the conclusion that vitamin D reduces the risk of falls by 19%, the risk of hip fracture by 18% and the risk of any non-vertebral fracture by 20%, however this benefit was dose-dependent. Fall prevention was only observed in trial of at least 700IU vitamin D per day, and fracture prevention required a received dose (treatment dose x adherence) of more than 400IU vitamin D per day. Anti-fall efficacy started with achieved 25-hydroxyvitamin D levels of at least 60nmol/l (24ng/ml) and anti-fracture efficacy started with achieved 25-hydroxyvitamin D levels of at least 75nmol/l (30ng/ml) and both endpoints improved further with higher achieved 25-hydroxyvitamin D levels. Based on these evidence-based data derived from the general older population, vitamin D supplementation should be at least 700-1000IU per day and taken with good adherence to cover the needs for both fall and fracture prevention. Ideally, the target range for 25-hydroxyvitamin D should be at least 75nmol/l, which may need more than 700-1000IU per day vitamin D in older individuals with severe vitamin D deficiency or those overweight.