During the study, researchers examined data on over 6,000 children ranging from ages 1 to 21. The data came from the 2001-2004 National Health and Nutrition Survey. The data is comprehensive because it combines interviews and physical examinations. It’s also representative of the US population as a whole.
Nine percent of children were found to be deficient in vitamin D and another 61 percent were insufficient. Regarding demographics and behavior, low levels of vitamin D were more common in children who were: older, female, obese, African-american, Mexican-american, drank milk fewer than once a week, or spent more than 4 hours a day playing videogames, using computers or watching TV.
Low levels of vitamin D were linked to poor bone health, lower levels of calcium, higher systolic blood pressure, and lower levels of HDL cholesterol. The last three factors are significant indicators for heart disease.
The authors recommend that children at risk for vitamin D deficiency be screened regularly. They also suggest parents take an active role in ensuring their children get adequate vitamin D through an appropriate combination of diet, supplements and sunlight exposure.