Many U.S. children, especially minorities, are in need of more Vitamin D, according to the new study.

The study authors reviewed data from the 2001-2006 National Health and Nutrition Examination Survey, and specifically the serum 25-hydroxyvitamin D levels in children, age 11 and younger.

Currently, the American Academy of Pediatrics recommends that children should have vitamin D levels of at least 50 nmol/L (20 ng/ml) and the authors found over 6 million children below this level.

Other studies in adults suggest that vitamin D levels should be at least 75 nmol/L (30 ng/ml). There were 24 million children below this level, including 92 percent of non-Hispanic blacks and 80 percent of Hispanics.

Although many studies have demonstrated associations between suboptimal levels of vitamin D and poor health outcomes, more studies are needed both to establish the role of vitamin D in these poor health outcomes, and to determine the appropriate vitamin D supplement requirements for children.