Vitamin D and skeletal health

Abstract

Purpose of reviewVitamin D is an important determinant of bone health and neuromuscular function. This article discusses recent research findings about the association of vitamin D and skeletal health with respect to parathyroid hormone, bone mineral density, physical performance, falls, and fracture. Recent findingsThe critical threshold to maximize adequate calcium absorption and suppress excess parathyroid hormone secretion is a 25-hydroxyvitamin D level of 30 ng/ml or 75 nmol/l. In a study of postmenopausal women on osteoporosis therapy, 45% of women taking 400 IU or more of vitamin D daily had serum 25-hydroxyvitamin D levels lower than 30 ng/ml compared with 63% taking less than 400 IU of vitamin D supplementation daily. In community-dwelling adults, a significant positive association was shown between 25-hydroxyvitamin D levels and total hip bone mineral density and lower extremity function. A meta-analysis of hip fractures demonstrated a 26% lowering of risk with doses of greater than 700 IU of vitamin D supplementation. Subsequent clinical trials showed similar reductions but were not statistically significant. SummaryThe inexpensive and simple practice of maintaining adequate vitamin D can contribute to decreasing fracture risk through skeletal and neuromuscular effects. Prevention strategies for fracture risk reduction should include vitamin D supplementation, particularly in the elderly.