Senior author Seema Kumar, MD, and colleagues studied 19 obese adolescents, aged 13 years to 18 years, with 25-hydroxyvitamin D (25[OH]D) levels that were less than 75 nmol/L. Treatment was 100,000 IU of vitamin D3 orally once a month for three months. Endothelial function was assessed by flow-mediated dilatation of the brachial artery at baseline and one month after the third dose of vitamin D3.
Although the mean level of 25(OH)D increased from 55.9 nmol/L to 86.9 nmol/L, the researchers found no correlation between 25(OH)D levels and flow-mediated dilatation of the brachial artery. They also found no significant changes in levels of calcium, fasting lipids, glucose, insulin, or high-sensitivity C-reactive protein. There was a slight decline in serum parathyroid hormone (3.8 pmol/L to 3.1 pmol/L).
“After three months of having vitamin D boosted into the normal range with supplements, these teenagers showed no changes in body weight, BMI, waistline, blood pressure, or blood flow,” said Dr. Kumar. “We’re not saying the links between vitamin D deficiency and chronic diseases don’t exist for children — we just haven’t found any yet.”