COLUMBIA, Mo.—Increasing the daily dose of vitamin D3 to the maximum intake level set by the Institute of Medicine (IOM) has been found to be a safe and effective method to improve vitamin D status in overweight and obese adolescents, according to researchers at the University of Missouri.
Vitamin D, essential for maintaining healthy bones, muscles, nerves and immunity, can be obtained from certain foods, such as fatty fish and eggs, dietary supplements and skin exposure to sunlight. IOM recommends 600 IUs per day, with a tolerable upper intake of 4,000 IUs..
“Obese adolescents face an increased risk for deficiency because they tend to absorb vitamin D in their fat stores, which prevents it from being utilized in their blood," said Catherine Peterson, associate professor of nutrition & exercise physiology. “We found that a daily dose of 4,000 IUs of vitamin D3, the maximum intake level set by the Institute of Medicine (IOM), is both safe and effective at improving vitamin D status in obese adolescents."
Participants from the MU Adolescent Diabetes and Obesity clinic were randomly selected to receive a placebo or 4,000 IU/day of vitamin D3 for six months as part of their standard treatment. All obese participants initially were deficient or insufficient in vitamin D status. Participants supplemented with vitamin D3 had significantly greater increases in concentrations of 25OHD, the main indicator of vitamin D status, compared to those who received the placebo. They found obese adolescents are only about half as efficient at using vitamin D as their lean counterparts. For example, in lean adolescents it only takes about 100 IUs to increase their serum 25OHD levels by 1 ng/ml. In obese adolescents, it takes about 200 IUs to achieve the same increase.
“If obese adolescents only consumed the recommended 600 IUs, they would be in trouble," Peterson said. “It takes 4,000 IUs to raise their vitamin D status within a sufficient range. This is much higher than the currently recommended daily amount for this age group. This indicates that physicians need to carefully evaluate the vitamin D status in their overweight and obese patients."
