Vitamin D and Bone Health in Postmenopausal Women

Abstract

Osteoporosis, a disease of increased skeletal fragility, is becoming increasingly common as the U.S. population ages. Adequate vitamin D and calcium intake is the cornerstone of osteoporosis prevention and treatment. Age-related changes in vitamin D and calcium metabolism increase the risk of vitamin D insufficiency and secondary hyperparathyroidism. Although longitudinal data have suggested a role of vitamin D intake in modulating bone loss in perimenopausal women, studies of vitamin D and calcium supplementation have failed to support a significant effect of vitamin D and calcium during early menopause. There is a clearer benefit in vitamin D and calcium supplementation in older postmenopausal women. Vitamin D intake between 500 and 800 IU daily, with or without calcium supplementation, has been shown to increase bone mineral density (BMD) in women with a mean age of approximately 63 years. In women older than 65, there is even more benefit with vitamin D intakes of between 800 and 900 IU daily and 1200–1300 mg of calcium daily, with increased bone density, decreased bone turnover, and decreased nonvertebral fractures. The decreases in nonvertebral fractures may also be influenced by vitamin D-mediated decreases in body sway and fall risk. There are insufficient available data supporting a benefit from vitamin D supplementation alone, without calcium, to prevent osteoporotic fracture in postmenopausal women.