According to a new study published online in the Journal of Gerontology elderly individuals with insufficient levels of vitamin D, regardless of whether obtained through diet, supplements or sun exposure, could have a higher risk of developing mobility problems and disability.

Leading researcher, Denise Houston, Ph.D., R.D., a nutrition epidemiologist in the Wake Forest Baptist Department of Geriatrics and Gerontology who studies vitamin D and its impact on physical function, declared: “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.”

The team analyzed the link between vitamin D and onset of mobility limitation and disability over a period of six years, having obtained data from the National Institute on Aging’s Health, Aging, and Body Composition (Health ABC) study that included 3,075 black and white men and women between the ages of 70 to 79 years, of which they 2,099 proved eligible for their study. The team defined the limitation of mobility and disability as any difficulty or inability to walk several blocks or climb a flight of stairs.

All eligible participants were healthy, free of any life-threatening illnesses, and none reported difficulty in walking one-fourth mile, climb 10 steps, or perform basic, day-to-day activities.

The team measured each participant’s vitamin D levels at the start of the study, assessing mobility limitation and disability at follow-up during annual clinic visits, which was alternated with telephone interviews every six months over a period of six years.

Houston commented: “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.”

She continued saying that vitamin D is important for muscle function, which explains why low levels of vitamin D can potentially lead to the onset of less muscle strength and reduced physical performance. Indirectly, vitamin D can also potentially affect physical function, given that low vitamin D-levels are linked to diabetes, high blood pressure, lung and cardiovascular disease, which are all common causes of reduced physical function. Vitamin D can be obtained through sun exposure, eating vitamin D rich foods like cereals, fortified milk and juice as well as by taking vitamin D supplements.

Houston said:

“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.”

People above the age of 70 years should under current recommendations have 800 International Units of vitamin D in their daily diet or take supplements. Houston underlines that these daily recommendation are solely based on the effect of vitamin D on bone health. She states: “Higher amounts of vitamin D may be needed for the preservation of muscle strength and physical function as well as other health conditions.”

Houston concludes: “However, clinical trials are needed to determine whether increasing vitamin D levels through diet or supplements has an effect on physical function.”

Written By Petra Rattue