Children are living such indoors lives that seven out of 10 American kids are low in vitamin D - which mainly comes from sunshine - and risk bone and heart disease as they get older.
The extent of the problem has shocked researchers, who thought the deficiency was relatively rare amongst children. But new data released by the National Health and Nutrition Examination Survey reveals that up to 58 million American children either have an insufficiency, or are deficient, in the vitamin. A deficiency can lead to high blood pressure, rickets and unhealthy bone growth.
Researchers say the problem has been caused by sedentary lives led indoors in front of the TV or computer, and by over-use of powerful sunblocks.
Consuming more milk and fish, both rich in vitamin D, would help, as would taking supplements - but the best antidote is to get out into the sunshine, say researchers. In a message to parents, lead researcher Michal Melamed at the Albert Einstein College of Medicine of Yeshiva University said: "It would be good for them to turn off the TV and send their kids outdoors. 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."
(Source: Pediatrics, 2009: published online: doi: 10.1542/peds.2009-0051).