August 3, 2009

Millions Of Children Lacking Vitamin D

Millions of US children have low levels of vitamin D, putting them at risk of bone and heart diseases and stroke, according to a study released on Monday.

Writing in the online version of the journal Pediatrics, researchers at Albert Einstein College of Medicine of Yeshiva University conducted a study of over 6,000 children to determine their levels of vitamin D.

"Several small studies had found a high prevalence of vitamin D deficiency in specific populations of children, but no one had examined this issue nationwide," said Dr. Michal L. Melamed, assistant professor of medicine and of epidemiology & population health at Einstein.

Researchers defined low levels of vitamin D as less than 15 ng/mL of blood. They studied more than 6,000 children, ages one to 21. Data was collected from the National Health and Nutrition Examination Survey (NHANES) 2001-2004.

The team determined that 9 percent of the cases studied was vitamin D deficient. That figure translated into about 7.6 million children in the US. Additionally, they noted that 61 percent, or 50.8 million US children "“ was vitamin D insufficient.

A lack of vitamin D can be related to problems with bone health as well as an increased risk of cardiovascular complications such as high blood pressure, heart attack and stroke.

Researchers also found that lower levels of vitamin D were more prevalent among children who were older, female, African-American, Mexican-American, obese, drank milk less than once a week, or spent more than four hours a day watching TV, playing videogames, or using computers.

"We expected the prevalence of vitamin D deficiency would be high, but the magnitude of the problem nationwide was shocking," lead author Dr. Juhi Kumar, a fellow in pediatrics at Children's Hospital at Montefiore Medical Center, The University Hospital and Academic Medical Center for Albert Einstein College of Medicine.

"We know from earlier NHANES data that vitamin D levels have declined over the last 20 years," added Dr. Melamed. "Kids have more sedentary lifestyles today and are not spending as much time outdoors. The widespread use of sunscreens, which block UV-B rays, has only compounded the problem."

She added that although dietary sources of vitamin D such as milk and fish are important, they are not always enough.

"It's very hard to get enough vitamin D from dietary sources alone," said Melamed.

The body uses UV-B sunlight to convert a form of cholesterol in the skin into vitamin D.

"The message for pediatricians is that vitamin D deficiency is a real problem with consequences not only for bone health but also potentially for long-term cardiovascular health. Pediatricians should be screening children for vitamin D levels, especially in the high-risk populations," said Dr. Kumar.

Melamed added that parents should "turn off the TV and send their kids outside. Just 15 to 20 minutes a day should be enough. And unless they burn easily, don't put sunscreen on them until they've been out in the sun for 10 minutes, so they get the good stuff but not sun damage."


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