Seven out of 10 children and young adults don't get enough vitamin D, which could increase their risk for bone and heart problems, a study suggests today.
A study of more than 6,000 children and young adults published online in the journal Pediatrics had striking results, says lead author Michal Melamed, assistant professor of medicine and epidemiology and population health. The study was led by scientists at the Albert Einstein College of Medicine of Yeshiva University in New York.
"Seventy percent of children -- millions of kids -- have inadequate levels for bone health," Melamed says.
Researchers analyzed data on people ages 1 to 21 collected by the National Health and Nutrition Examination Survey 2001-2004. They discovered that 9% of the study sample -- which would project to 7.6 million people 21 and under in the USA -- were vitamin-D-deficient. An additional 61%, the equivalent of 50.8 million nationwide, had insufficient D levels.
Vitamin D deficiency is defined as a blood level of less than 15 ng/mL (nanograms/milliliter). Vitamin D insufficiency is the term used when that figure falls between 15 and 29 ng/mL. Anything over 30 ng/mL is considered a healthy range.
D-deficiency was more common in older children as well as female, African-American, Mexican-American and obese kids, and in those who drank milk less frequently than once a week, Melamed says. D-deficiency was also more common in kids who spent more than four hours a day watching TV, playing video games or using computers, she says.
"The study has enormous public health implications and heightens the concern about the health status of children," says vitamin D researcher JoAnn Manson, chief of preventive medicine at Brigham and Women's Hospital in Boston.
Low vitamin D levels at such a young age could predispose them to other diseases later in life linked to D deficiency, including diabetes, hypertension, heart disease and cancer, Manson says.
Melamed says today's culture of computers, TV and video games, less milk drinking, and increased use of sunscreens, which block UV-B rays -- the kind that help the body convert a form of cholesterol in the skin into vitamin D -- are likely culprits in waning vitamin D levels among youngsters.
To see more of USAToday.com, or to subscribe, go to http://www.usatoday.com
Copyright 2009 USA TODAY, a division of Gannett Co. Inc.