Older adults who don't get enough vitamin D – either from their diets or exposure to the sun – may be at increased risk of poor physical performance and disability, new research warns.
About a quarter of people over age 60 have low vitamin D levels. Previous research has shown that vitamin D not only plays a role in bone health, but possibly also in protecting against diabetes, cancer, colds and tuberculosis.
"With a growing older population, we need to identify better ways to reduce the risk of disability," says American investigator Dr Denise Houston of the Wake Forest University School of Medicine. "Our study showed a significant relationship between low vitamin D levels in older adults and poorer physical performance."
Vitamin D is naturally produced when the skin is exposed to the sun's ultraviolet rays. Foods like fortified milk, juice and cereals also contain vitamin D, but it is difficult to get enough through diet alone.
Older adults are particularly prone to low vitamin D levels because they may get less exposure to sunlight and because their skin is less efficient at producing vitamin D from sun exposure.
The researchers found that people with low levels of vitamin D have about 10 per cent lower physical strength. Houston says that vitamin D plays an important role in muscle function, so it is plausible that low levels of the vitamin could result in lower muscle strength and physical performance.
Current recommendations call for people from age 50 to 69 to get 400 international units (IUs) of vitamin D per day and for those over age 70 to get 600 IUs. Many researchers, however, suggest that higher amounts may be needed.
"Higher amounts of vitamin D may be needed for the preservation of muscle strength and physical function as well as other conditions such as cancer prevention," says Houston. "The current recommendations are based primarily on vitamin D's effects on bone health.”
But people seeking a vitamin D boost should be wary of getting too much of a good thing – just one burn doubles your risk of developing skin cancer. Read more: British Sun Worshippers 'Intend to Burn'.