Lack of vitamin D linked to mobility difficulties in older adults
Older adults who don’t get enough vitamin D – either from diet, supplements or sun exposure – may be at increased risk of developing mobility difficulties, according to a recent study by the Wake Forest Baptist Medical Center.
Researchers collected data from 2,099 participants aged 70-79 who reported no difficulty walking one-fourth mile, climbing 10 steps, or performing basic, daily living activities, and were free of life-threatening illness. Vitamin D levels were measured in the blood. Occurrence of mobility difficulties during follow-up was assessed during annual clinic visits alternating with telephone interviews every six months over six years.
Lead author, Denise Houston, Ph.D., R.D., a nutrition epidemiologist in the Wake Forest Baptist Department of Geriatrics and Gerontology said:
“We observed about a 30 percent increased risk of mobility limitations for those older adults who had low levels of vitamin D, and almost a two-fold higher risk of mobility disability. About one-third of older adults have low vitamin D levels. It’s difficult to get enough vitamin D through diet alone and older adults, who may not spend much time outdoors, may need to take a vitamin D supplement.”
Houston said vitamin D plays an important role in muscle function, so it is plausible that low levels of the vitamin could result in the onset of decreased lower muscle strength and physical performance. Vitamin D may also indirectly affect physical function as low vitamin D levels have also been associated with diabetes, high blood pressure, cardiovascular disease and lung disease – conditions that are frequent causes of decline in physical function. Houston said people get vitamin D when it is naturally produced in the skin by sun exposure, by eating foods with vitamin D, such as fortified milk, juice and cereals, and by taking vitamin D supplements.
Current recommendations call for people over age 70 to get 800 International Units of vitamin D daily in their diet or supplements. Houston pointed out that current dietary recommendations are based solely on vitamin D’s effects on bone health.
“Higher amounts of vitamin D may be needed for the preservation of muscle strength and physical function as well as other health conditions,” she said. “However, clinical trials are needed to determine whether increasing vitamin D levels through diet or supplements has an effect on physical function.”
The above story is reprinted from materials provided by Wake Forest Baptist Medical Center.
Where do you find vitamin D in the diet?
Although vitamin D is essential for good health, unless you get adequate sun exposure it is difficult to get your needs from food alone. On average, Australians eat 2-3 mcg of vitamin D each day, which is less than the 5 mcg recommended to young people, and much less than the 15 mcg needed by older folk (the body’s ability to generate active vitamin D diminishes with age).
The main dietary sources of vitamin D are oily fish, margarine, eggs and milk fortified with vitamin D. These generally provide 1-2 mcg of D per serve. Some powdered drinks and soy beverages are also fortified with D.
Wild mushrooms are naturally high in vitamin D. In some parts of Australia Vitamin D Mushrooms are available. They have been exposed to light and respond by making vitamin D. They provide around 20 mcg of vitamin D per 100g serve (three button mushrooms). That’s at least your daily needs in a single serve. Mushrooms are the only non-animal natural source of vitamin D.
Expert comment by Glenn Cardwell, Accredited Practising Dietitian.