The present invention provides a method for increasing the intestinal (lymphatic) absorption, cellular concentration, biliary secretion, hepatic storage, and/or liver concentration of a fat soluble vitamin in a post-menopausal woman. The method comprises orally administering to a post-menopausal woman in need thereof, a fat soluble vitamin and a fat soluble vitamin absorption increasing effective amount of L-carnitine. The L-carnitine enhances the antioxidant defense mechanism and lowers the risk of certain degenerative diseases, such as coronary heart disease, age-related macular degeneration, osteoporosis, cancer, and Alzheimer's, in post-menopausal women. The invention also provides a method for increasing the intestinal absorption of a fat soluble vitamin in an animal. The method comprises orally administering to the animal in need thereof, a fat soluble vitamin and a fat soluble vitamin absorption increasing effective amount of L-carnitine.