Vitamin D = Better Quality of Life?
Reported April 27, 2010
(Ivanhoe Newswire) As we live longer than ever, concern has shifted from the mere quantity of years to the importance of the quality of those years. Osteoporosis, arthritis, and other serious and often painful bone and joint diseases emerge as we get older. Seniors struggle with what was once the simple task of getting around. The obvious question concerning our longevity is, “What choices can we make to help ease these inconveniences of aging?”
One area of particular interest is the role that diet plays in keeping bones and muscles strong into old age. Studies point to the possibility that optimal intake of vitamin D, the “sunshine” vitamin, might help keep our muscles strong and preserve physical function.
To help understand this diet-health association, Dr. Denise Houston and colleagues from the Sticht Center on Aging at Wake Forest University studied the relationship between vitamin D status and physical function in a group of relatively healthy seniors living in Memphis, TN and Pittsburgh, PA.
At the beginning of the study, researchers assessed vitamin D status by analyzing each participant’s blood for 25-hydroxyvitamin D, a precursor for activated vitamin D. At baseline and then at two and four years later, the research team determined whether circulating 25-hydroxyvitamin D was related to the participants’ physical function. They looked at how quickly each participant could walk a short distance, rise from a chair five times and maintain his or her balance in progressively more challenging positions. Each participant was also put through a battery of tests assessing endurance and strength.
Participants with the highest levels of 25-hydroxyvitamin D had better physical function. And, although physical function declined over the course of the study, it remained significantly higher among those who had the highest vitamin D levels at the beginning of the study.
While higher circulating 25-hydroxyvitamin D was related to better physical function in seniors, it was not possible to tell from this type of research whether increasing vitamin D intake would actually lead to stronger muscles and preserve physical function. This is partly due to the fact that our bodies can make vitamin D if they get enough sunlight. So, it is possible that the participants with better physical function had higher vitamin D status simply because they were able to go outside more often.
Nonetheless, it is possible that getting more vitamin D from foods like fortified milk and oily fish or supplements will help maintain youth and vitality as we enjoy longer life.
Houston was quoted as saying, “Current dietary recommendations are based primarily on vitamin D’s effects on bone health. It is possible that higher amounts of vitamin D are needed for the preservation of muscle strength and physical function as well as other health conditions. However, clinical trials are needed to definitively determine whether increasing 25-hydroxyvitamin D concentrations through diet or supplements has an effect on these non-traditional outcomes.”
SOURCE: Presented at the American Society for Nutrition meeting, Anaheim, CA, April 25, 2010
