milk may be putting children's bones at risk from low vitamin D levels.
A new study shows more than half of otherwise healthy children have low
vitamin D levels in their blood, which may put them at risk for bone diseases,
Vitamin D-fortified milk is the main source of vitamin D in the diet, but
the vitamin is also produced within the body as a result of sunlight
That's why researchers say those low vitamin D levels may reflect current
trends of children spending less time outdoors and drinking less milk than in
Severely low levels of vitamin D can lead to muscle weakness, bone weakness,
and rickets. Earlier studies -- cited by the researchers -- show that vitamin D
also plays an important role in immune system function.
Vitamin D and Kids
In the study, published in the American Journal of Clinical
Nutrition, researchers analyzed blood levels of vitamin D in 382 healthy
children from ages 6 to 21.
They found 55% of the children had lower than recommended vitamin D
African-American children, children over age 9, and those who didn't get
much vitamin D in their diet were the most likely to have low levels of the
vitamin in their blood.
Vitamin D levels also dropped during winter. Overall, 68% of children had
inadequate stores of the vitamin in their blood during the colder months when
they spent more time indoors.
"Vitamin D deficiency remains an under-recognized problem overall, and
is not well studied in children," says researcher Babette Zemel, PhD, a
nutritional anthropologist at Children's Hospital of Philadelphia, in a news
Zemel says more study is needed to determine appropriate blood levels of
vitamin D in children, and a review of current recommendations for vitamin D
intake may be needed.
By Jennifer Warner
Reviewed by Louise Chang
B)2005-2006 WebMD, Inc. All rights reserved