New York, Aug 15 (IANS): Giving obese teenagers extra vitamin D pills can elevate their cholesterol and fat-storing triglycerides levels, an Indian American researcher has discovered.

Seema Kumar, pediatric endocrinologist in the Mayo Clinic Children's Centre also found no benefits of extra vitamin D supplements in improving heart health or decreasing diabetes risk.

Parents and providers often put obese adolescent children on vitamin D regiments -- sometimes at more than 5-to-10 times the recommended daily intake.

"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," Kumar noted.

"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," she added.

This is the first of Kumar's studies to report increased cholesterol and triglycerides during vitamin D supplementation.

Kumar has been studying the effects of vitamin D supplementation in children for 10 years through four clinical trials and six published studies.

To date, her team has found limited benefit from vitamin D supplements in adolescents.

She, however, calls for larger, placebo-controlled studies to examine the long-term effects of vitamin D supplementation on teenagers and children.

"This is because some studies have shown a link between vitamin D in the blood and improved vascular function," Kumar said in a paper appeared online in the journal Pediatric Obesity.

She opted to study vitamin D in overweight teenagers because this population is at increased risk for chronic disease.

According to her, 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.

"I am surprised that we haven't found more health benefit," Kumar added.