ABSTRACT
Carnitine nutriture received very little attention until the first carnitine-deficient patient was discovered. It had not been considered as a possible essential nutrient for humans or for animals, although lysine has now been shown to be a precursor for carnitine. The amino acid lysine and carnitine share the same precursor-product relationship as tryptophan and niacin, but carnitine has not been given the same status of vitamin as niacin. Rebouche and Engel studied carnitine biosynthesis from TML in man and rat. Tissue carnitine deficiency has been shown to occur in rats fed on cereal diets known to be deficient in essential amino acids, particularly lysine. Ascorbic-acid deficiency in guinea pigs has been shown to reduce tissue carnitine levels. Carnitine deficiency in humans can be expected in diseases of the kidney and heart and also in various genetic disorders. Carnitine has proved to be therapeutically useful in the treatment of these disorders, as well as certain types of amino acidurias.
