Widespread vitamin D deficiency poses risk: study

By Andrew Stern

CHICAGO (Reuters) - Many young children do not get enough vitamin D, an often invisible deficiency that can show up later as broken bones or a weakened immune system prone to disease, researchers said on Monday.

Two out of five U.S. children aged 8 months to 2 years who took part in a 380-patient study at Children's Hospital Boston had less-than-optimal blood levels of vitamin D.

The main risk factors were not drinking enough fortified milk, not taking vitamins and being overweight, said the report published in the Archives of Pediatric and Adolescent Medicine.

Lead researcher Catherine Gordon of Children's Hospital Boston said the 40 percent deficiency rate "is higher than expected in a country that has vitamin D fortified milk."

The study adds to a growing body of evidence that vitamin D, made when sunlight hits the skin and used to fortify many foods, is important for preventing chronic diseases. It is key to maintaining strong bones but has also been linked with a lower risk of cancer, artery disease and even kidney disease.

The lack of symptoms, at least initially, led Gordon to call it a "silent disease."

"What was striking to us was how many infants were vitamin D deficient but they were asymptomatic. The silence of what we saw worries me more," she said in a telephone interview.

The alternative to a blood test to discover a deficiency is to routinely give vitamins that can be consumed easily in the form of liquid drops, she said.