NFS382H1 Lecture Notes - Lecture 17: Vitamin K Deficiency, Glutathione Peroxidase, Cytochrome P450
Document Summary
Alpha-tocopherol is the only biologically active form: tocotrienols. Other forms exist, but the body can"t metabolize or interconvert them. Tocopherols: fully saturated side-chain, alpha-tocopherol has the most substitution on the ring structure (3 methyl groups) Tocotrienols: unsaturated side-chain, same alpha, beta, gamma, delta distinction, not much known about this class. Determined for adults by testing plasma alpha-tocopherol concentrations after red blood cell hemolysis: vitamin e does not have a good biomarker for its status, thus this test is used instead. Lactation: age-specific requirement plus average vitamin e in breast milk. Fat-soluble vitamin: destroyed relatively easily by light and heat, cooking the oil will destroy it. Found in: certain vegetable oils, seeds and nuts. Tocotrienols are esterified and must be hydrolyzed, but we don"t know much about how they"re absorbed. Improved by dietary lipids: absorbed via chylomicrons, circulated via lymph system, leftovers returned to liver.