An exclusively or partially breastfed baby should receive 400 IU of viatmin D each day starting in the first few days of life. The supplement should be continued until an infant is weaned to 32 ounces of vitamin D fortified formula or started on cow's milk.
Carlson's is a popular natural vitamin D supplement. One drop placed directly on one nipple at one feeding per day will give a full day's supply. D-visol, 1 dropper per day, is a popular supplement as well.
Please call if you have any additional questions.