Sir.—Rickets caused by vitamin D deficiency in breast-fed infants is rarely reported in patients from the southern part of the United States. Milder winters, a perennially sunny climate, and liberal vitamin D supplementation are the most likely reasons for this low incidence. We report four cases of rickets in breast-fed black infants who received no vitamin D supplementation. Except for one patient, there was no history of patients being overdressed or deprived of sunlight exposure. Lack of familiarity with the disease, stemming from the rarity of its occurrence in warm climates,
probably delayed the diagnosis in two cases.
Patient Reports.—Patient 1.—A 13-month-old black boy presented to the Pediatric Clinic of the United States Air Force (USAF) Medical Center, Keesler Air Force Base, Miss, with failure to thrive, inability to walk, and muscle weakness.