Senior Citizens Need More Vitamin D to Prevent Loss of Mobility
Low vitamin D indicated 30% increased risk of mobility; almost a two-fold higher risk of mobility disability
May 29, 2012 - Older adults – seniors age 70 to 79 in this study - who don't get enough vitamin D from diet, supplements
or sun exposure may be at increased risk of developing mobility limitations and disability, according to new research from
Wake Forest Baptist Medical Center. Mobility limitation was defined as difficulty
in walking several blocks or climbing a flight of stairs. Disability was determined by the inability to do these things.
"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," said lead author
Denise Houston, Ph.D., R.D., a nutrition epidemiologist in the Wake Forest
Baptist
Department of Geriatrics and Gerontology. Houston researches vitamin D and its
effects on physical function.
The study, published online this month in the Journal of Gerontology: Medical Sciences, 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
Aging's Health, Aging, and Body Composition (Health ABC) study.
Of the 3,075 community-dwelling black and white men and women aged 70-79 who were enrolled, data from 2,099 participants
was used for this study.
Eligible participants 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 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 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," Houston said.
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.
"About one-third of older adults have low vitamin D levels," she said. "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."
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."
This research was supported in part by the Intramural Research Program of the National Institutes of Health, National
Institute on Aging and the Wake Forest University Claude D. Pepper Older Americans Independence Center.
Co-authors include: Janet A. Tooze, Ph.D., Gary G. Schwartz, Ph.D., Jeff D. Williamson, M.D., Stephen B Kritchevsky,
Ph.D., Rebecca H. Neiberg, Ph.D. and M. Kyla Shea, Ph.D., all of Wake Forest Baptist; Dorothy B. Hausman, Ph.D., and Mary Ann Johnson, Ph.D.,
University of Georgia, Athens; Jane A. Cauley, Ph.D., University of Pittsburg, Pennsylvania; Doug C. Bauer, M.D., University of California,
San Francisco; and Tamara B. Harris, M.D., National Institute on Aging.
Review of 28 studies finds the vitamin associated
with a substantial decrease in cardiovascular disease, type 2 diabetes
and metabolic syndrome for seniors and middle aged - Feb. 16, 2010
Researchers also urging close monitoring of elderly
with hypertension during weather extremes; second study says thinking
ability varies with blood pressure
May 29, 2012 - Older adults – seniors age 70 to 79 in this study - who don't get enough vitamin D from diet, supplements
or sun exposure may be at increased risk of developing mobility limitations and disability, according to new research from
