Suboptimal vitamin D found in millions of US children*

Monday Oct 26, 2009 (foodconsumer.org) -- Millions of children in the United States aged 1 to 11 may suffer suboptimal levels of vitamin D, a large nationally representative study suggests. Black and Hispanic children are at particularly high risk.

The study led by Jonathan Mansbach, MD, at Children's Hospital Boston and colleagues and published in the November issue of Pediatrics analyzed vitamin D levels in U.S. children.

There is a debate over the optimal level of vitamin D. The American Academy of Pediatrics recommends children have vitamin D levels of at least 20 ng/mL or 50 nmol/L. But some studies in adults suggest as high as 30 ng/mL (75 nmol/L) or even 40 ng/mL (100 nmol/L) is needed to lower the risk of heart disease and specific cancers.

Mansback and colleagues used data from the national health and Nutrition Examination Survey (NHANES) to look at vitamin D levels in about 5,000 children from 2001 to 2006.

They found about 20 percent of the children fell below the recommended 50 nmol/L and more than two-thirds including 80 percent of Hispanic children and 92 percent of Black children had vitamin D levels below 75 nmol/L.

"If 75 nmol/L or higher is eventually demonstrated to be the healthy normal level of vitamin D, then there is much more vitamin D deficiency in the U.S. than people realize," Mansbach said.

Mansbach and his co-authors suggest that all children, particularly those who live in high latitudes where the sun is scare in the wintertime, should take vitamin D supplements because recent studies suggest that it may prevent a host of common pediatric illnesses such as respiratory infections, childhood wheezing, and winter-related eczema among others.

"We need to perform randomized controlled trials to understand if vitamin D actually improves these wide-ranging health outcomes," Mansbach said. "At present, however, there are a lot of studies demonstrating associations between low levels of vitamin D and poor health. Therefore, we believe many U.S. children would likely benefit from more vitamin D."

Dr. John Cannell, a vitamin D expert and president of Vitamin D Council suggests that children younger than two years can take 1,000 IU daily safely while older children can take 2,000 IU a day and adults can take 5,000 IU each day safely to maintain a good level of this vitamin in the blood.

By David Liu