Rickets returning; breastfed infants at risk

New research advocates vitamin D supplements to prevent the nutritional deficiencies that can lead to this disease.

By Victoria Stagg Elliott, amednews staff. Sept. 4, 2000.

Infants who are exclusively breastfed, particularly those with dark skin, should receive vitamin D supplements to prevent rickets, a disease on the rise, according to a study in the August Journal of Pediatrics.

The return of rickets is a classic example of the sometimes cyclical nature of public health challenges. For years, this illness has been associated more with 19th century novels than mainstream health care. Still, it appears to be staging a comeback because of cultural influences.

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"We have seen a 4.4 increase in North Carolina in the number of African-American babies who are breastfeeding with the disease and a threefold increase in all babies who are breastfeeding," said Robert Schwartz, MD, a pediatric endocrinologist at Wake Forest University School of Medicine in Winston-Salem, N.C., and an author of the study.

African-Americans and others with dark complexions absorb less sunlight than those with lighter skins, making them at higher risk for the nutritional deficiency that can lead to retarded growth, bone deformities and convulsions.

Breast milk still perfect nutrition

Commercially available infant formulas have included vitamin D since the 1930s, but breast milk is naturally low in vitamin D.

The study's authors emphasized, however, that the increase in rickets has not been caused by a return to breastfeeding but by a reduction in the time people spend outdoors.

"Breast milk is perfect nutrition for babies," said Shelley Kreiter, MD, the primary author of the study and an assistant professor of pediatrics at Wake Forest University. "Unfortunately, our culture has changed, and babies get less sunlight exposure. Breast milk has always been low in vitamin D. Breast milk today is no different from what it was a million years ago."

The researchers are recommending vitamin supplementation rather than increased sunlight because it is unclear how much sun is enough -- or safe. "If I was a breastfeeding mother, I wouldn't want to have to wonder, 'Did I get my baby enough sunlight today?' " said Dr. Kreiter.

Researchers are also recommending the supplementation for all exclusively breastfed infants, rather than just for those of a certain race or ethnicity, because pigmentation varies significantly within groups. They also want to make the practice guidelines as simple as possible. "It takes the guesswork out for the physician," said Dr. Kreiter.

Physicians who advocate breastfeeding say they support the recommendations and always consider supplements as necessary.

"If people knew how to safely spend time in the sunlight, I don't think this would be a problem," said Mary Dobbins, MD, a pediatrician with the Quincy (Ill.) Medical Group and the breastfeeding coordinator for the American Academy of Pediatrics' Illinois chapter. "I think vitamin D supplementation will be a uniform recommendation in the not-too-distant future."

Doctors working in public health support the move because vitamin supplements generally are inexpensive and accessible, and small excesses are rarely problematic.

"I don't think there's much danger in doing this, and it will make it simple," said Brad Gessner, MD, a pediatric epidemiologist with the Alaska Public Health Dept.

Alaska has long had programs in place to combat rickets because the state's long, dark winters put its residents at increased risk. Dr. Gessner questioned, however, whether the move was necessary for all states and said physicians should use their judgment in recommending supplementation rather than making it universal.

"I think there's probably not much data that I see that would support the need for a black infant in Florida during the summer getting vitamin D, for example. Physicians around the country may determine for themselves what the likelihood is that their patients really need it," he said. "I think there will be a lot of kids getting vitamin D that they don't need with these recommendations."

ADDITIONAL INFORMATION:

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Journal of Pediatrics (http://www.mosby.com/jpeds/) for August editorial "Vitamin D-deficient rickets: The reemergence of a once-conquered disease," and article "Nutritional rickets in African American breast-fed infants."