Vitamin D deficiency is common among elderly Koreans and is highly likely in men to coexist with cardiovascular disease risk factors, including excess belly fat, a new study finds. The results will be presented Saturday at The Endocrine Society’s 92nd Annual Meeting in San Diego.
“To the best of our knowledge, this is the first report in an elderly Korean population about the relationship between vitamin D deficiency and obesity,” said study co-author Nan Hee Kim, MD, PhD, associate professor at Korea University in Ansan. “We can no longer consider vitamin D a nutrient for just bone health.”
Increasingly, research is finding that vitamin D deficiency affects metabolism and correlates with a higher death rate, Kim said. Vitamin D deficiency becomes more common as we age, affecting up to 50 percent of older adults, according to several U.S. studies.
In Kim’s study of 491 Koreans ages 65 and older, more than 69 percent of men and nearly 87 percent of women had vitamin D deficiency. A total of 218 men and 273 women participated in the study. The researchers divided subjects into four groups, or quartiles, of vitamin D level and compared the metabolic risk factors among each group.
For unknown reasons, the lowest vitamin D level was linked to high glucose (blood sugar), high triglycerides (blood fats) and abdominal obesity only in men and not women, the authors reported. All three problems are part of the metabolic syndrome, a cluster of cardiovascular disease risk factors that also includes low HDL, or “good,” cholesterol and high blood pressure. People have the metabolic syndrome if three of the risk factors are present.
The metabolic syndrome also raises the chance of having a fatty liver, which over time can sometimes damage the liver. Both men and women in this study had approximately 5 times the odds of having a fatty liver if their vitamin D level was in the lowest quartile, Kim said.
Only 37 study subjects reported that they were taking vitamin or calcium supplements. The study results did not change whether or not the researchers included these subjects in their analysis, Kim said. Likewise, she said they adjusted for exercise level and other factors that could influence the results, and the findings did not significantly change.
“Elevating vitamin D status via either vitamin D supplementation or increasing sunlight exposure time might be a useful tool for metabolic benefit,” Kim said.
Sun exposure is controversial because of the risk of skin cancer. However, Kim said, “Most experts agree that children and adults alike require 800 to 1,000 International Units of vitamin D3 per day to satisfy the body’s vitamin D requirement.”
Sources of vitamin D in the diet include fatty fish, egg yolks, and foods fortified with vitamin D.
