Recently in our household we have learned about the importance of Vitamin D for good health. This interesting article gives just one more reason to make sure we are getting enough in our diet. We do not get enough from sunshine alone.
As you get older, you may notice your knees are less forgiving when
it comes to jaunting up and down the stairs. A study supported in part
by the U.S. Department of Agriculture's (USDA) Agricultural Research Service
(ARS) suggests that if you're not getting adequate vitamin D in your
diet, you may be at increased risk of developing the painful condition
known as "osteoarthritis" in your knees.
Osteoarthritis occurs when the natural cushioning between joints in
the body wears away-allowing bones to rub together. With an estimated 27
million people succumbing to osteoarthritis, there is significant
interest in finding ways to prevent or treat the condition.
The team of researchers, led by epidemiologist Fang Fang Zhang and including nutritionist Sarah Booth,
investigated the possible interaction between circulating blood levels
of vitamin D and the progression of knee osteoarthritis in adults. Booth
is the associate director at the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University in Boston, Massachusetts, and Zhang is assistant professor of epidemiology at the Friedman School of Nutrition Science and Policy at Tufts University.
The scientists looked at a subset of data collected during a longitudinal study called the Osteoarthritis Initiative
(OAI), which is a large study of individuals with, or at risk of, knee
osteoarthritis. The researchers focused on 418 volunteers for whom blood
serum concentrations of vitamin D were available and for whom
radiographs to assess knee osteoarthritis progression were available.
The volunteers were followed for 4 years and monitored for knee
osteoarthritis progression and vitamin D levels in their blood.
Compared to volunteers with healthy levels, participants with low
vitamin D levels had more than doubled the risk of their knee
osteoarthritis worsening during the study. The scientists concluded that
vitamin D deficiency is a risk factor for increased knee osteoarthritis
progression and that increased, adequate dietary intake may be
beneficial for those with knee osteoarthritis.
ARS is USDA's principal intramural scientific research agency. Read more about this research in the July 2015 issue of AgResearch magazine.