Millions US Kids Have Low Vitamin D Levels

Seven out of 10 U.S. children don’t get enough vitamin D. It puts them at risk of heart disease, rickets, and weak bones.

Nearly one in 10 kids -- 7.6 million American children -- are actually deficient in vitamin D. Low vitamin D is risky, but vitamin D deficiency is a serious health threat in which the body begins to reabsorb calcium from the skeleton, WebMD reports.

"It's astounding," said Michal L. Melamed of the Albert Einstein College of Medicine in New York, who helped conduct one of the studies published online by the journal Pediatrics. "At first, we couldn't believe the numbers. I think it's very worrisome."

Low Vitamin D levels are especially common among girls, adolescents and people with darker skin, according to the analysis of a nationally representative sample of more than 6,000 children. For example, 59 percent of African American teenage girls were Vitamin D deficient, Melamed's study found.

The researchers and others blamed the low levels on a combination of factors, including children spending more time watching television and playing video games instead of going outside, The Washington Post reports.

The body turns sunlight into vitamin D; not surprisingly, the researchers found that kids who spent more than four hours a day watching television, playing video games and using computers were more likely to have low levels of vitamin D. Milk is often fortified with vitamin D, and drinking milk less than once a week was also associated with lower levels of the vitamin.

“This appears to be another result of our unhealthy lifestyles, including a sedentary society that doesn’t go out in the sun much,” one of the authors of the study told the Washington Post, The Wall Street Journal reports.