Although diet can affect lactation, human milk volume and composition are resilient and remain relatively consistent across a wide variety of diets.[1][2] Eating enough calories and staying hydrated builds an important dietary foundation for milk production. The additional energy demand of lactation is estimated at about 450 to 500 kcals per day (see below). Lactating people also have an increased requirement for protein, choline, many vitamins (including A, C, E, and most B vitamins), and the minerals iodine, selenium, and zinc.[3][4] However, if a parent’s diet is deficient in the nutrients required to make milk, their body will mobilize and (if necessary) deplete fat, vitamin, and mineral stores to meet the demands of lactation, even at the expense of the parent’s health. A balanced, nutrient-dense diet can protect the parent from dietary deficiencies while also supporting ongoing lactation.