April 23, 2007
Low Vitamin D Levels Linked To Poor Physical Performance In Older Adults: Role Of Vitamin D In Cancer TreatmentTopics: Medical Science News
New research from Wake Forest University School of Medicine and colleagues suggests adults who don't get enough vitamin D - either from their diets or exposure to the sun - may be at increased risk for poor physical performance and disability:
"With a growing older population, we need to identify better ways to reduce the risk of disability," said lead author Denise Houston, Ph.D. "Our study showed a significant relationship between low vitamin D levels in older adults and poorer physical performance."
The results are reported in the April issue of the Journal of Gerontology: Medical Sciences.
About one-fourth 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.
"Recent findings showing the importance of vitamin D status on multiple health outcomes underscore the need for more research on the effects of low vitamin D levels in elderly populations," said Houston, an instructor in internal medicine - gerontology.
Vitamin D is naturally produced when skin is exposed to the sun's ultraviolet rays. Foods such as fortified milk, juice and cereals also contain vitamin D, but it is difficult to get enough through diet alone, said Houston.
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 in producing vitamin D from sun exposure compared to younger adults. Older adults also may not get enough vitamin D from dietary sources.
... The researchers found that physical performance and grip strength were about five to 10 percent lower in those who had low levels of vitamin D. After looking at other variables that could influence the results, such as body mass index, physical activity, the season of the year, mental abilities, health conditions and anemia, the results held true.
... the results suggest the need for additional research in this area, said Houston. She said 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. (More on the study and its findings here)
Vitamin D is a group of fat-soluble prohormones, the two major forms of which are vitamin D2 (or ergocalciferol) and vitamin D3 (or cholecalciferol). In addition to helping the body absorb calcium, vitamin D also helps the body keep the right amount of calcium and phosphorus in the blood (More on Vitamin D here). Back in 2005, cancer prevention specialists at the Moores Cancer Center of the University of California at San Diego reported that 1,000 international units (IU) of vitamin D3 daily appeared to lower an individual's risk of developing certain cancers - including colon, breast, and ovarian cancer - by up to 50 percent, according to at the University of California, San Diego (UCSD) Medical Center:
This complex analysis of virtually every observational study written on the subject, called a systematic review, paints a clearer picture than any single study and is recognized by scientists as an important tool for establishing a consensus of findings.
"A preponderance of evidence, from the best observational studies the medical world has to offer, gathered over 25 years, has led to the conclusion that public health action is needed," Garland said. "Primary prevention of these cancers has largely been neglected, but we now have proof that the incidence of colon, breast, and ovarian cancer can be reduced dramatically by increasing the public's intake of vitamin D."
Since the safety of daily intake of vitamin D3 in the recommended range has been thoroughly assessed and confirmed by the National Academy of Sciences, and the benefits found so far in observational studies are considerable, expanded use of vitamin D as a public health measure should not be delayed, according to the authors.
They recommend intake of 1,000 IU/day of vitamin D, half the safe upper intake established by the National Academy of Sciences. Garland said that while this study looked at all forms of vitamin D - intake through diet or supplements, and photosynthesis through modest sun exposure - as a practical matter, the majority of people will most easily achieve the target levels by eating foods containing vitamin D and taking supplements, which the authors estimated would cost about five cents per day.
Posted by Richard at April 23, 2007 2:46 PM
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