An error occurred in the article by Hollis BW et al, titled “Maternal Versus Infant Vitamin D Supplementation During Lactation: A Randomized Controlled Trial” published in the October 2015 issue of Pediatrics (2015;136[4]: 625–634; doi:10.1542/2015-1669). On page 630, in Fig 2, Fig 2C should be labeled as Fig 2B and, conversely, Fig 2B should be labeled as Fig 2C. The current figure legends are correct.