Older adults who dont get enough vitamin D may be at increased risk of developing mobility limitations and disability, according to a study.
“This is one of the first studies to look at the association of vitamin D and the onset of new mobility limitations or disability in older adults,” lead author Denise Houston, PhD, RD, a nutrition epidemiologist in the Wake Forest Baptist Department of Geriatrics and Gerontology, said in a news release.
The study analyzed the association between vitamin D and onset of mobility limitation and disability over six years of follow-up using data from the National Institute on Agings Health, Aging, and Body Composition study. Mobility limitation and disability were defined as any difficulty or inability to walk several blocks or climb a flight of stairs, respectively.
The researchers used data from 2,099 community-dwelling black and white men and women ages 70 to 79. Eligible participants reported no difficulty walking a quarter of a 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 at the beginning of the study. Occurrence of mobility limitation and disability during follow-up was assessed during annual clinic visits alternating with telephone interviews every six months over six years.
“We observed about a 30% increased risk of mobility limitations for those older adults who had low levels of vitamin D, and almost a twofold higher risk of mobility disability,” Houston said.
Houston said vitamin D plays an important role in muscle function, meaning low levels of the vitamin could result in the onset of decreased lower-muscle strength and physical performance. Low vitamin D levels also have been associated with diabetes, hypertension, cardiovascular disease and lung disease — conditions that are frequent causes of decline in physical function.
“About one-third of older adults have low vitamin D levels,” Houston said. “Its difficult to get enough vitamin D through diet alone, and older adults, who may not spend much time outdoors” thus limiting their exposure to sunlight “may need to take a vitamin D supplement.”
Current recommendations call for people older than 70 to get 800 international units of vitamin D daily in their diet or through supplements. Houston pointed out that current dietary recommendations are based solely on vitamin Ds 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 study appears in the June issue of the Journal of Gerontology: Medical Sciences. To read the abstract and access the study via subscription or purchase, visit http://bit.ly/Kyhdd8.