News - Exercise and vitamin D help to reduce falls in the elderly
A new systematic review of 54 clinical studies, published in the Annals of Internal Medicine and commissioned by the U.S. Preventative Services Task Force, finds that exercise and vitamin D supplements are the most effective ways to prevent falls in older men and women.
Falls are a major problem in older individuals, and the leading cause of death and disability for people aged 65 and over. Around 30% of adults in this age group who are not institutionalised will fall each year, and the number of falls among older adults is increasing, partly because the elderly population is growing fast.
About 15-20% of elderly people who fall and fracture a hip die within a year of their injury. Hip fractures related to falls cost the NHS in England an estimated £1.7 billion (compared with stroke at £2.1 billion). Therefore, understanding how to reduce the number of falls is crucial. Previous research has identified an unexpected risk factor for the falls suffered by many elderly people – vitamin D deficiency.
The main source of vitamin D in the body comes from exposing the skin to the sun’s ultraviolet B (UVB) radiation, although a diet rich in fatty fish can provide some vitamin D. The liver and kidneys then convert vitamin D – generated under the skin by sunlight or obtained from food – into its active hormonal form.
Vitamin D is best known for its crucial role in bone health. But recently, scientists have discovered that vitamin D is active in many tissues and cells besides bone and over 200 genes are directly influenced by vitamin D, including some associated with cancers, autoimmune conditions such as multiple sclerosis, rheumatoid arthritis and type 1 diabetes, and infection.
It is estimated that approximately one billion people worldwide do not have sufficient vitamin D. If you live in more northern climes where there is less sunlight, for example in the UK, vitamin D deficiency is a potential problem. In addition, the skin’s production of vitamin D is influenced by age, and those aged 65 and over generate only a quarter as much as people in their 20s do. The problem is compounded by the fact that many of the elderly are house-bound or stuck in nursing homes and rarely get outdoors, always cover their skin when outside, and do not eat fatty fish, which naturally contains vitamin D.
Yvonne Michael, associate professor at Drexel University in Philadelphia, and her colleagues, set out to determine what interventions might be useful for primary care physicians to prescribe to their older patients.
Dr Michael and colleagues reviewed 54 randomised controlled trials, which included a total of more than 26,000 participants, 65 years of age and over. The 18 trials looking at exercise and physical therapy showed that exercisers had a 13% lower risk of falling compared to those who did not exercise. Some of these trials involved group exercise or thai chi classes; others involved individualised exercise instruction at home. Most exercises were aimed at improving balance, strength and flexibility needed to do everyday activities.
The researchers then evaluated nine clinical trials where participants received daily oral doses of vitamin D with or without calcium. The participants who received vitamin D had a 17% reduced risk of falling compared to those in control groups who did not receive vitamin D. These results are not surprising considering the beneficial effects of vitamin D on bone and muscle function.
Other interventions that addressed single risk factors – including vision correction, medication assessment, home hazard modification, clinical education and behavioural counselling – did not significantly reduce the risk of falling. However, trials that were comprehensive in managing the multiple fall risk factors did reduce the risk of falling by 11%.
Lead researcher Dr Michael commented: “Our evidence review shows that exercise and vitamin D supplementation are the most effective primary care interventions to prevent falls.”
“We need to do more study,” Michael said, “but, on the basis of this review, I think there is fairly stable evidence that physicians can successfully reduce the percent of those who fall through vitamin D supplementation.”
In search of vitamin D
Researchers suggest that10-15 minutes of sunlight, taken at the beginning and end of each day when the sun is less strong, can generate most of the vitamin D we need. That is why vitamin D is often called the “sunshine” vitamin. However, the season, the time of day, where you live, cloud cover and pollution, age, skin colour and sunscreen use affect the amount of UVB that reaches your skin and therefore the amount of vitamin D you produce. Further, very few foods naturally contain vitamin D, and you would need to eat a large quantity of them to get enough of the sunshine vitamin. So unless you live in a southern climate and spend time outdoors, or you like eating lots of oily fish, supplements are the best way to make sure you are getting enough of this important vitamin.
Michael YL, Whitlock EP, Lin JS et al. Ann Intern Med. 2010;153:815-25.