PHTY400 Lecture 5: Vitamins
Document Summary
Thirteen different vitamins have been isolated, analyzed, clas- sified, synthesized, and assigned rdas. D, e, and k or water soluble vitamin c and the b-complex vitamins: thiamine (b1), riboflavin (b2), vitamin b6 (pyridoxine), niacin (nicotinic acid), pantothenic acid, biotin, folic acid (folacin or folate, its active form in the body), and cobalamin (b12). Fat-soluble vitamins dissolve and remain in the body"s fatty tissues, obviating the need to ingest them daily. It may take years before unhealthy symptoms emerge that denote a fat- soluble vitamin deficiency. The liver stores vitamins a and d, whereas vitamin e distributes throughout the body"s fatty tis- sues. Vitamin k stores only in small amounts, mainly in the liver. Dietary lipids are the source of fat-soluble vitamins; these vitamins, transported as part of lipoproteins in the lymph, travel to the liver for dispersion to various tissues. Consuming a true fat-free diet would certainly accelerate a fat-soluble vitamin insufficiency.
