The study, published in the Journal of the American Medical Association Pediatrics, used surveys, physical exams, and blood tests to find factors that affect vitamin D status. The researchers used data from 1,898 healthy children between one and five years old, such as answers to questions about their daily screen time, time spent outdoors, skin pigmentation, and milk and supplement intake. Their age, height, weight, and the season in which their vitamin D level was tested were recorded.
The lab test used to measure vitamin D status is called 25-hydroxyvitamin D.
These factors appeared to affect vitamin D status:
Vitamin D deficiency in young children has long been known to cause problems with bone development, but more recently scientists have begun to link chronic vitamin D insufficiency with other childhood health problems like allergies and asthma. In addition, poor vitamin D status during childhood might increase the risks of heart disease and certain cancers in adulthood.
Recognizing vitamin D’s important role in childhood and lifelong health, the study’s authors said, “Vitamin D supplementation and sensible cow’s milk intake represent excellent targets for increasing 25-hydroxyvitamin D level[s] in young children.” The American Academy of Pediatric recommends 400 IU of vitamin D per day for infants and children.
(JAMA Pediatr 2013; doi: 10.1001/2013.jamapediatrics.226.)