By Melissa Schorr
B O S T O N, Aug. 10
An exclusive diet of breast milk could be putting some babies at risk for vitamin D deficiency and thus at risk for rickets, a bone-weakening disorder that has been virtually nonexistent in the United States for decades.
Doctors nationwide are reporting a small spike in the number of breast-fed babies developing nutritional rickets, Rickets is caused by a lack of vitamin D, which is crucial for strong bone development. It can result in stunted growth, broken bones and bow legs in children.
Breast milk, though an excellent source of nutrition overall, provides little vitamin D. Babies can get the vitamin instead from a splash of sunlight or from a daily supplement.
But rickets may be on the rise, researchers believe, because of the renewed popularity of breast-feeding, along with doctors’ failure to properly prescribe vitamin D supplements to breast-feeding moms.
Dark Skin, High Risk At special risk are dark-skinned babies, whose pigmentation prevents them from using sunlight to produce the necessary vitamin D.
But babies of any race who aren’t getting enough vitamin D from their diet and aren’t getting a daily dose of sunlight are potentially at risk of developing rickets, researchers say.
Doctors at two medical centers in North Carolina report in this month’s issue of the Journal of Pediatrics that they saw 30 cases of rickets in breast-fed black infants from 1990 though 1999, with more than half of the cases occurring in the last 18 months alone.
This June, researchers at the University of Texas Southwestern Medical Center in Dallas published a report in the journal Texas Medicine about a recent outbreak of rickets among dark-skinned infants who were breast fed, despite the presence of abundant sunlight in the state.
Statewide Surge Cases of rickets have been popping up around the country, from New York to Florida, notes Dr. Robert P. Schwartz, an endocrinologist at Wake Forest University School of Medicine in Winston-Salem, N.C., lead author of the study.
Schwartz decided to study the issue along with his colleagues, Dr. Shelley Kreiter, a pediatrician at Wake Forest, and Dr. Henry Kirkman of the University of North Carolina School of Medicine in Chapel Hill.
Because of growing concerns, the Centers for Disease Control will be putting out a bulletin on rickets this fall, a spokesman says.
“This is a disease that was here 100 years ago,” Schwartz says. “It’s back.”
History of Rickets
As late as the 1940s, rickets was a common childhood ailment, killing thousands of children annually until doctors learned that that vitamin D in milk and sunlight could largely prevent it.
Today, fortified milk and prepared baby formula both contain vitamin D, largely eliminating the problem.
But because breast milk contains much lower levels of vitamin D, babies exclusively fed on it may be at risk, especially if they have darker skin that blocks out sunlight; live in northern climates and receive less light or have moms with vitamin D deficiencies themselves.
The number of African-American women who are breast-feeding has been on the rise in the past decade, from about 5 to 22 percent, the Pediatrics study reports.
“We’re glad to see that more minority women are breast-feeding, and we don’t want them scared away because they hear their breast milk is not sufficient,” says Carol Huotari, manager for the Center for Breastfeeding Information at La Leche League International, a Schaumburg, Ill.-based group that promotes breast-feeding. “It’s a simple thing to provide vitamin D supplements.”
“We don’t want to come across as against breast-feeding,” Schwartz concurs. “But we think all infants should be supplemented with vitamins.”
Since January, Schwartz’ group has provided supplements to more than 700 women in North Carolina who are exclusively breast-feeding. The supplements are paid for by the federal Health Resources and Services Administration’s Maternal and Child Health Block Grant program.
“Proving supplements to every baby seems like overkill,” says Huotari, “when it’s just a selected group of babies that would benefit.”
But Schwartz says many infants are potentially at risk and the cost has been minimal so far: about $1.50 per infant per month — far less than hospitalizing infants for fractures and broken bones.
Doctors Fail to Warn Besides the increase in breast-feeding contributing to this rise in rickets, pediatricians also may not be telling mothers to supplement the breast milk with vitamin D.
The Journal of Pediatrics study surveyed 400 North Carolina pediatricians and found that 16 percent weren’t prescribing vitamin supplements at all. Younger doctors, who may have never seen a case of rickets, were less likely to prescribe vitamin D than older ones.
“Doctors have not been led to believe it is essential,” Schwartz explains.
Schwartz says the American Academy of Pediatricians hasn’t established clear enough guidelines on supplementation.
In 1998, the academy recommended vitamin D supplements be used for breast-fed infants with dark skin or inadequate exposure to sunlight, but other earlier policy statements still in effect haven’t provided a clear mandate for vitamin use.
“The nice thing is, this disease doesn’t have to occur at all,” Schwartz says. “This is 100 percent preventable.”