Most recent update: Friday, June 22, 2018 - 09:50

Bariatric News - Cookies & privacy policy

You are here

Vitamin D in teens

No cardiac or metabolic benefit for Vitamin D in teens

Kumar and colleagues have been studying the effects of vitamin D supplementation in children for ten years, through four clinical trials and six published studies
To date, they have found limited benefit from vitamin D supplements in adolescents. Several observational studies also have noted links between vitamin D deficiency and a host of weight-related medical complications

Dosing obese teens with vitamin D shows no benefits for their heart health or diabetes risk and could have the unintended consequences of increasing cholesterol and fat-storing triglycerides, according to the findings in a series of Mayo Clinic studies into childhood obesity, 'Effect of vitamin D3 treatment on endothelial function in obese adolescents', published in the journal Pediatric Obesity.

Seema Kumar

"After three months of having vitamin D boosted into the normal range with supplements, these teenagers showed no changes in body weight, body mass index, waistline, blood pressure or blood flow," said Dr Seema Kumar, a pediatric endocrinologist in the Mayo Clinic Children's Center. "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."

Kumar and colleagues have been studying the effects of vitamin D supplementation in children for ten years, through four clinical trials and six published studies. To date, they have found limited benefit from vitamin D supplements in adolescents. Several observational studies also have noted links between vitamin D deficiency and a host of weight-related medical complications, including cardiovascular diseases and insulin resistance. As a result, caregivers and providers often start high-dose supplementation in an attempt to slow or reverse some of the clinical complications associated with obesity.

They team decided to study vitamin D in overweight teens because this population is at increased risk for chronic disease and because of the compound's increasing popularity as a homeopathic or complementary treatment for obesity. The study sought to determine whether treatment with vitamin D3 improves endothelial function in obese adolescents. A total of 19 obese adolescents, 13–18 years of age, with 25-hydroxy vitamin D (25[OH]D) levels <75 nmol L−1 were treated with 100 000 IU vitamin D3 orally once a month for three months in an open-label, single-centre prospective trial. Endothelial function was assessed by flow-mediated dilatation (FMD) of the brachial artery at study entry and one month after the third dose of vitamin D3. Biochemical parameters, including calcium, fasting lipids, glucose, insulin and high-sensitivity C-reactive protein, were also obtained.

The mean 25(OH)D levels increased from 55.9 ± 12.2 to 86.9 ± 16.7 nmol L−1 (p<0.01). There was no correlation between 25(OH)D levels and brachial artery FMD. The brachial artery FMD (%) did not change significantly following vitamin D3 treatment (9.5±3.53 vs. 10.3±3.83, p=0.83). Serum parathyroid hormone declined from 3.8±1.5 to 3.1±1 pmol L−1 (p=0.01). The remainder of biochemical measurements did not show a significant change.

"I have been surprised that we haven't found more health benefit," she added. "We're not saying it's bad to take vitamin D supplements at reasonable doses, and we know most obese teens are vitamin D deficient. We're just saying the jury is still out on how useful it is for improving overall health in adolescents."

This is the first of their studies to report increased cholesterol and triglycerides during vitamin D supplementation, a finding she said might be attributed to the smaller number of children who participated in the study and the relatively short timeframe. She has called for larger, placebo-controlled studies to examine the long-term effects of vitamin D supplementation on teens and children.

Kumar notes 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.

Want more stories like this? Subscribe to Bariatric News!

Bariatric News
Keep up to date! Get the latest news in your inbox. NOTE: Bariatric News WILL NOT pass on your details to 3rd parties. However, you may receive ‘marketing emails’ sent by us on behalf of 3rd parties.