Adequate vitamin D level reduces fall and fracture risk

Vitamin D supplementation should be at least 700–1,000 IU per day to cover the needs for both fall and fracture prevention, according to a new review.

The review analyzes two most recent meta-analyses of randomized controlled trials coming to the conclusion that vitamin D dose-dependently reduces the risk of falls by 19%, the risk of hip fracture by 18% and the risk of any non-vertebral fracture by 20% in elderly people (1). Fall prevention was observed only at 700 IU vitamin D per day, and fracture prevention required a received dose of more than 400 IU vitamin D per day.

The author commented that current intake recommendations of 200 to 600 IU vitamin D per day may be insufficient for important disease risk reduction by vitamin D. Ideally, the target range for 25-hydroxyvitamin D should be at least 75 nmol/liter, which may need more than 700–1,000 IU vitamin D in individuals with severe vitamin D deficiency or those overweight.

Critical for the understanding and prevention of fractures, especially at older age, is their close relationship with muscle weakness and falling. Over 90% of fractures occur after a fall and fall rates increase with age and poor muscle strength or function. Several lines of evidence support a role of vitamin D in muscle health: muscle weakness is a prominent feature of the clinical syndrome of vitamin D deficiency. In several randomized controlled trials, vitamin D supplementation increased muscle strength and balance, and reduced the risk of falling.

The author concluded that there is strong evidence that many or most adults in the United States and Europe would benefit from vitamin D supplements with respect to fracture and fall prevention, and possibly other public health targets, such as cardiovascular health, diabetes and cancer.

Another recent analysis of 25 double-blind randomized controlled trials showed that higher doses of vitamin D resulted in the prevention of falls and fractures in elderly populations, as well as in risk reduction of colorectal cancer and protection of cardiovascular health (2). The data suggests that in blood serum mean 25(OH) vitamin D levels of about 75 to 110 nmol/L provide optimal benefits without increasing health risks. These levels can be best obtained with oral doses in the range of 1,800 to 4,000 IU vitamin D per day, the authors suggested.

1. Bischoff-Ferrari H. Vitamin D: What is an adequate vitamin D level and how much supplementation is necessary? Best Practice & Research Clinical Rheumatology. 2009; 23:789–795.
2. Bischoff-Ferrari H. et al. Benefit–risk assessment of vitamin D supplementation. Osteoporosis International . December 2009.