Fewer children are at risk of having insufficient or deficient levels of vitamin D, according to a recent study.

Researchers from the Loyola University Chicago Stritch School of Medicine found that under the new Institute of Medicine guidelines - which say most people get sufficient vitamin D when their blood levels are at or above 20 nanograms per milliliter - 10.3 percent of children ages 6 to 18 are at risk of inadequate or deficient vitamin D levels. By comparison, a 2009 study in the journal Pediatrics, found that an estimated 70 percent of people ages 1 to 21 had deficient or insufficient vitamin D levels.

For the study, researchers studied vitamin D data from a nationally representative sample of 2,877 U.S. children and adolescents ages 6 to 18 who participated in the National Health and Nutrition Examination Survey.

Under previous guidelines, which defined sufficient vitamin D levels as greater than 30 ng/mL, millions of children who had vitamin D levels between 20 and 30 ng/mL would have needed supplementation.

Under the new Institute of Medicine guidelines, children in this range no longer need to take vitamin D supplements.

Researchers found that children at risk of vitamin D deficiency under the Institute of Medicine guidelines are more likely to be overweight, female, non-white and between the ages of 14 and 18.

The Institute of Medicine's new vitamin D guidelines are based on nearly 1,000 published studies and testimony from scientists and other experts.

The Institute of Medicine suggest that vitamin D is essential to avoid poor bone health, such as rickets.

"But there have been conflicting and mixed results in studies on whether vitamin D can also protect against cancer, heart disease, autoimmune diseases and diabetes. Moreover, excessive vitamin D can damage the kidneys and heart," according to researchers.

The findings were published in the Journal of Pediatric Endocrinology and Metabolism