Amino acid that is present in many foods, among them the milk. Indication is the treatment of Primary Deficiency of Carnitine, or, Secondary Deficiency due to Hemolysis, Myocardiopathy and other diseases. Only Levocarnitine is effective as a supplement, with the consumption of D-carnitine regarded as a risk for deficiency. Normal levels in the milk are not modified by the consumption of supplements of Carnitine. Mean concentration level within the first month is about 10 to 12 mg/L, with lower levels in the next following months. The supplementation with Carnitine of the milk for premature infants does not improve their weight increment, with no proof of a beneficial effect.