Nursing motherIn the October 2015 issue of Pediatrics, two MUSC Children’s Hospital faculty members—vitamin D researcher Bruce W. Hollis, Ph.D., and neonatologist Carol L. Wagner, M.D.—reported clinical trial findings definitively showing that sufficient vitamin D can be transmitted via breast milk to meet the needs of the exclusively breastfed infant, provided that the mother is adequately supplemented.

Breastfeeding is encouraged by the medical community in part because breast milk meets all nutritional needs of the child, with the glaring exception of vitamin D. Why such an essential vitamin would be missing from breast milk has always been puzzling. Many physicians erroneously believe that vitamin D simply cannot be transmitted via breast milk. To prevent deficiency in exclusively breastfed babies, the American Academy of Pediatrics recommends that they be supplemented with 400 IU/d of vitamin D3, delivered via liquid drops. Unfortunately, the drops can be difficult to administer and not all mothers adhere to this directive, leaving some infants vulnerable to rickets or fractures.

The study results reported by Hollis and Wagner suggest that a more natural and effective way to supplement the child would be to adequately supplement the nursing mother.  At the time the study was designed, the Institute of Medicine (IOM) recommended that adults, even nursing mothers, receive 400 IU/d of vitamin D3; the IOM has since increased the recommended dose to 600 IU/d. The study randomized mother/infant dyads to either 400 IU/d of vitamin D3 each or 6,400 IU/d for the mother and none for the infant. The infants in both arms of the trial achieved vitamin D sufficiency, and no adverse effects were reported for mothers receiving the 6,400/IU day dose.  The results suggest that adequate maternal supplementation—6,400 IU/d of vitamin D3 vs. the current IOM recommendation of 600 IU/d—offers a safe and effective alternative to direct infant supplementation.