Vitamin D, exercise fall short for fall prevention in older women

NEW YORK - In a Finnish study of older women, vitamin D supplements increased bone density slightly, and exercise improved physical functioning, but neither treatment reduced the rate of falls.

"Falls are the leading cause of unintentional injuries and fractures in older adults, head injuries and fractures being the most severe consequences," Dr. Kirsti Uusi-Rasi, of the UKK Institute for Health Promotion Research in Tampere, Finland, told Reuters Health by email.

Both exercise and vitamin D are recommended for fall prevention for older people, despite mixed supportive evidence.

"Because there is hardly any evidence about exercise and vitamin D together, we investigated the separate and combined effects of multimodal exercise training and vitamin D supplementation in reducing falls and injurious falls among older women at risk for falling," she explained.

The researchers assigned 409 community-dwelling women ages 70 to 80 to receive placebo without exercise, vitamin D (800 IU/d) without exercise, placebo plus exercise, or vitamin D plus exercise, for two years. Exercise consisted of supervised group training classes focusing on balance, weights, agility, and strengthening. The classes met twice weekly the first year and once weekly the second year.

Neither vitamin D nor exercise reduced overall falls, the primary outcome, they reported online March 23 in JAMA Internal Medicine.

Fall rates per 100 person-years were 118.2 (placebo without exercise), 132.1 (vitamin D without exercise), 120.7 (placebo plus exercise) and 113.1 (vitamin D plus exercise).

However, the rate of injurious falls (a secondary outcome) was cut by more than half among exercisers with or without vitamin D.

Rates of injurious falls were 13.2 in the placebo without exercise arm and 12.9 in the vitamin D without exercise arm, versus 6.5 and 5.0 in the placebo plus exercise and vitamin D plus exercise arm, respectively. The hazard ratios were 0.47 for the placebo plus exercise group and 0.38 for the vitamin D plus exercise group.

Vitamin D helped maintain bone density in the femoral neck and increased tibial trabecular density in the shinbone; exercise improved muscle strength and balance, but vitamin D didn't enhance the effects of exercise on physical functioning.

"Based on our results there is no indication for higher doses of vitamin D, because the current guidelines for vitamin D intake (800 IU/day) seem to be well sufficient for attaining optimal serum 25OHD levels (50-70 nmol/L or 20-30 ng/mL) in healthy community-dwelling older women," Dr. Uusi-Rasi told Reuters Health.

"Higher doses need not be taken unless specifically indicated. In clinical practice it is essential to remember that exercise is key in maintaining physical functioning in older persons. Exercise also seems to reduce the severity of falls, resulting in fewer injuries," she added.

In an editorial, Dr. Erin S. LeBlanc of Kaiser Permanente Northwest and Dr. Roger Chou of Oregon Health & Science University, both in Portland, Oregon, write: "Given its low cost and low risk, vitamin D should remain in the physician's armamentarium for fall prevention, at least until more data are available. Taking a person's vitamin D status into account may be a useful clinical consideration."

"As more high-quality (randomized clinical trials) release their findings, we need to be ready to reevaluate the role that vitamin D has in maintaining health. However, the (trial) by Uusi-Rasi and colleagues reminds us that the strongest and most consistent evidence for prevention of serious falls is exercise, which has multiple other health benefits," they conclude.

In a statement, Duffy MacKay, senior vice president, scientific and regulatory affairs, Council for Responsible Nutrition said, "It is a well-known fact that Americans are getting insufficient amounts of vitamin D. This new study confirms the established role of vitamin D for bone health, but there are many other beneficial reasons for people to supplement with vitamin D."

"Other studies have pointed to a role for vitamin D in helping with cognitive function and reducing the risk of heart disease, diabetes and other chronic diseases; however, it is important to manage expectations for vitamin D's role in isolation and to remember that optimal nutrition is just one component of many needed to prevent chronic disease," he said.

"Additionally, we know that adverse health outcomes for under-consumption of vitamin D exist. Low levels of vitamin D have been associated with increased risk of falls, fractures, cardiovascular disease, colorectal cancer, type 2 diabetes mellitus, depressed mood, cognitive decline, and mortality," MacKay said.

"As a naturopathic doctor, I will continue to recommend vitamin D to my patients for all of its many benefits," MacKay added.

The study was supported by the Academy of Finland, Ministry of Education and Culture, Competitive Research Fund of Pirkanmaa Hospital District, and Juho Vainio Foundation.

SOURCE: http://bit.ly/1BIvbyZ

JAMA Intern Med 2015.

References: Reuters Health
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