Vitamin D is a normal component of human milk. Daily maternal vitamin D supplementation in the 400 to 2,000 IU (10 to 50 mcg) range produces milk concentrations that are inadequate to deliver the daily requirement to an exclusively breastfed infant, and inadequate to correct pre-existing infant vitamin D deficiency through breastfeeding alone. Breastfeeding mothers who take vitamin D supplements in this range should give their infants a daily vitamin D supplement of at least 400 IU (10 mcg) to meet pediatric nutritional guidelines.[1-5] Daily maternal vitamin D dosages at or above 4,000 IU (100 mcg) achieve milk levels can potentially meet the daily infant goal intake of at least 400 IU (10 mcg), depending on the mother's underlying vitamin D status and daily infant milk intake. Obese mothers may have higher requirements. Holder pasteurization decreased median levels of the major forms of vitamin D in breastmilk by 20% in one study.[6]