Reports of vitamin D deficiency rickets, although rare in the United States, have increased over the past few years, including in children living in climates with abundant sunshine. The purpose of this study was to describe vitamin D recommendation practices among pediatric health care providers in Las Vegas, Nevada. Of the 155 providers surveyed, 52.3% did not recommend vitamin D for exclusively breastfed babies. Providers who were more likely to recommend supplementation were doctors of medicine, were female, specialized in pediatrics, were of Hispanic ethnicity, had previously practiced and trained in states less sunny than Nevada, had graduated from training 21 or more years previously, had taken histories of infants' sun exposure, and had clinical experience with cases of rickets. Providers demonstrated a knowledge deficitforquestions that dealt with preventive measures.