Millions of U.S. children found Vitamin D deficient

By Sheilah Downey

The most recent vitamin D study found that children between the ages of 1 and 11 suffer from deficiencies of the vital vitamin, and adds that black and Hispanic children are at a "particularly high risk."

Growing evidence is showing that levels of vitamin D, which are known to prevent some cancers and a host of other illnesses, are falling below healthy numbers, according to a Children's Hospital of Boston press release.

The study, led by Dr. Jonathan Mansbach of Children's Hospital, used data from the National Health and Nutrition Examination Survey to look at vitamin D levels in about 5,000 children from 2001 to 2006.

Their analysis suggests that approximately 20 percent of all children fell below the recommended amount of 50 nmol/l (nanomoles of vitamin D per liter of blood) and that more than two-thirds of all children fell below those levels.

That two-thirds number included 80 percent of Hispanic children and 92 percent of non-Hispanic black children who fell below the 75 nmol/L levels.

"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," said Mansbach.

Vitamin D, and the optimal amounts considered healthy, are under heated debate in the medical community, with studies showing differing numbers.  The American Academy of Pediatrics recommends children should have vitamin D levels of at 50 nmo/l while other studies say adults should have 75 nmol/L and possibly as high as 100 per liter in order to lower risk of heart disease and specific cancers.

Mansbach and co-authors suggest that all children take vitamin D supplements, in light of the low levels found, to improve bone health and prevent rickets in children. The vitamin has also been found to prevent respiratory infections, childhood wheezing and winter-related eczema.

"We need to perform randomized controlled trials to understand if vitamin D actually improves these wide-ranging health outcomes," said Mansbach. "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."

Also mixing into the vitamin D debate is the possible affect that  sunscreens might have had on deficiencies being widely reported.

While the AAP recommends sunblock, some studies have concluded that the effect of sunscreen on preventing vitamin D into the blood system is significant. Reductions as great as tenfold have been reported.

More recent studies on sunscreen, that looked at results for months, and sometimes years, suggest that the effect is slight. While sunscreen does hamper its production, these studies say, it is not enough to cause a vitamin D deficiency.

According to the National Institutes of Health, it takes as little as 30 minutes of daytime exposure twice a week to produce adequate amounts of vitamin D.

Most health experts agree that rather than cutting back on sunscreen, people concerned about vitamin D should consume more foods rich in vitamin D, such as salmon, milk and orange juice.

The Mansbach study, with collaborators from the University of Colorado, Denver, and Massachusetts General Hospital, was published in the November issue of Pediatrics.