Childhood and adolescent obesity rates in the United States have increased dramatically in the past three decades. Being obese puts individuals at greater risk for developing Type 2 diabetes, a disease in which individuals have too much sugar in their blood. Now, University of Missouri researchers found vitamin D supplements can help obese children and teens control their blood-sugar levels, which may help them stave off the disease.

“By increasing vitamin D intake alone, we got a response that was nearly as powerful as what we have seen using a prescription drug,” said Catherine Peterson, an associate professor of nutrition and exercise physiology at MU. “We saw a decrease in insulin levels, which means better glucose control, despite no changes in body weight, dietary intake or physical activity.”

Peterson and her colleagues studied 35 pre-diabetic obese children and adolescents who were undergoing treatment in the MUAdolescent Diabetic Obesity Program died 35 pre-diabetic obese children and adolescents who were undergoing treatment in the MU Adolescent D. All of those in the study had insufficient or deficient vitamin D levels and had similar diets and activity levels. Study participants randomly were assigned either a high-dose vitamin D supplement or a placebo that they took daily for six months. Those who took the supplement became vitamin D sufficient and lowered the amount of insulin in their blood.

“The vitamin D dosage we gave to the obese adolescents in our study is not something I would recommend for everyone,” Peterson said. “For clinicians, the main message from this research is to check the vitamin D status of their obese patients, because they’re likely to have insufficient amounts. Adding vitamin D supplements to their diets may be an effective addition to treating obesity and its associated insulin resistance.”

Vitamin D helps maintain healthy bones, muscles and nerves and enters bodies through sunlight exposure, diet or supplements. Vitamin D insufficiency is common; however, it can be more detrimental to those who are obese, Peterson said.

“What makes vitamin D insufficiency different in obese individuals is that they process vitamin D about half as efficiently as normal-weight people,” Peterson said. “The vitamin gets stored in their fat tissues, which keeps it from being processed. This means obese individuals need to take in about twice as much vitamin D as their lean peers to maintain sufficient levels of vitamin D.”

Adding vitamin D supplements is a natural, inexpensive way to help obese children and teens decrease their odds of developing diabetes and avoid the side effects that might come from taking prescriptions to control their blood sugar, Peterson said.

The study, “Correcting vitamin D insufficiency improves insulin sensitivity in obese adolescents: a randomized controlled trial,” was published in the American Journal of Clinical Nutrition.