Absorption and metabolism of carnitine Adults eating mixed diets that include red meat and other animal products obtain about 60–180 milligrams of carnitine per day [6]. Vegans get considerably less (about 10–12 milligrams) since they avoid animal-derived foods. Most (54–86%) dietary carnitine is absorbed in the small intestine and enters the bloodstream [1,6]. The kidneys efficiently conserve carnitine, so even carnitine-poor diets have little impact on the body’s total carnitine content [1,5]. Rather than being metabolized, excess carnitine is excreted in the urine as needed via the kidneys to maintain stable blood concentrations. When can a carnitine deficiency occur? Two types of carnitine deficiency states exist. Primary carnitine deficiency is a genetic disorder of the cellular carnitine-transporter system that usually manifests itself by five years of age with symptoms of cardiomyopathy, skeletal-muscle weakness, and hypoglycemia. Secondary carnitine deficiencies may occur due to certain disorders
