Parents often put obese adolescent children on vitamin D regiments, sometimes at more than five to ten times the recommended daily intake. Dr. Seema Kumar, pediatric endocrinologist in the Mayo Clinic Children's Center has recommended that giving obese teenagers extra vitamin D pills can elevate their cholesterol and fat-storing triglycerides levels. Dr. Kumar also found no benefits of extra vitamin D supplements in improving heart health or decreasing diabetes risk.
Dr. Kumar said, "After three months of having vitamin D boosted into the normal range with supplements, the teenagers showed no changes in body weight, body mass index, waistline, blood pressure or blood flow. We are not saying the links between vitamin D deficiency and chronic diseases do not exist for children - we just haven't found any yet."
Dr. Kumar suggests that it is possible to ingest too much vitamin D, a condition called vitamin D toxicity or hypervitaminosis, which can result in poor appetite, nausea, vomiting and kidney complications. She has been studying the effects of vitamin D supplementation in children for 10 years through four clinical trials and six published studies. Dr. Kumar opted to study vitamin D in overweight teenagers because this population is at an increased risk for chronic disease. To date, her research team has found limited benefit from vitamin D supplements in adolescents.
Dr. Kumar, however, calls for larger, placebo-controlled studies to examine the long-term effects of vitamin D supplementation in teenagers and children. She said, "This is because some studies have shown a link between vitamin D in the blood and improved vascular function. I am surprised that we haven't found more health benefit."
The study appeared online in Pediatric Obesity.