Vitamins

Vitamins are an organic compound other than a carbohydrate, lipid, or a protein that is needed for normal metabolism but that the body cannot synthesize in adequate amounts. Vitamins are considered micronutrients because while they are necessary for the healthy functioning of the human body, they are only required in small amounts. Vitamins are obtained from foods, being natural components of foods where they are usually present in minute amounts, or from provitamins, which are precursor substances. Vitamins are essential for normal physiological function; if vitamins are absent from the diet or underutilized, there will be a specific deficiency syndrome.

Vitamins provide coenzymes, therefore functioning as catalysts in the body. A catalyst is a substance that allows a chemical reaction to occur using less energy and less time than it would take under normal conditions. Catalysts in the body allow reactions in the body to take place at lightning speed and at the normal temperatures of cells. (Otherwise, the cells would need to increase their temperature, which would severely hurt the cells, and biochemical reactions we need on a moment’s notice would take hours.) A coenzyme is a non-protein substance that is necessary for the activity of a particular enzyme. (An enzyme is a protein that catalyzes a specific biochemical reaction.) Often an enzyme is inactive until it combines with a non-protein component, like a coenzyme, that either helps the active site attain its appropriate shape or helps bind the enzyme to its substrate.

The way vitamins get into the body to catalyze these reactions is the digestive process, during which they are absorbed through the small intestine. There are two main types of vitamins: those that are fat-soluble and those that are water-soluble. Fat-soluble vitamins are usually absorbed with the help of foods that contain fat. Fat containing these vitamins is broken down by bile and then the body absorbs the breakdown products and vitamins. Excess amounts of fat-soluble vitamins are stored in the body’s fat, liver, and kidneys. Water-soluble vitamins are absorbed with water and are rapidly lost by the body because they are not stored.

Thirteen vitamins are essential to life. Four of these vitamins are fat-soluble, which include vitamin A, D, E, and K; the other nine are water-soluble—they are vitamin B1, B2, B6, B12, nicotinic acid, pantothenic acid, folic acid, biotin, and Vitamin C.

Considering the fact that vitamins are considered micronutrients, it is incredible all that they do! Below is a chart that briefly outlines some of their roles in the body.

How Vitamins Work in the Body

And

What They Do for the Body

By Heather Richards

Vitamin B-12 illustrated

The Roles Vitamins Play in the Body
Vitamin A	Necessary for the formation of visual purple in the eye, which increases night vision; prevents eyes from drying out; nourishes the whites of the eye; needed for the synthesis of mucoproteins and mucopolysaccharides; for normal development of bones and teeth; and for maintenance of epithelial cells.
Vitamin D	Promotes absorption of calcium and phosphorus; promotes development of teeth and bones.
Vitamin E	Prevents oxidation of vitamin A and polyunsaturated fatty acids; may help maintain stability of cell membranes; may have anti-aging properties.
Vitamin K	Required for synthesis of prothrombin, which functions in blood coagulation.
Vitamin B1 (thiamine)	Helps growth, digestion, and the health of nerves and muscles; acts as a coenzyme in the production of acetylcholine; part of coenzyme required for oxidation of carbohydrates; coenzyme required in ribose synthesis.
Vitamin B2 (riboflavin)	Part of enzymes and coenzymes, such as FAD; required for oxidation of glucose and fatty acids and for cellular growth; significant in the maintenance of the skin and mucous membranes, the cornea of the eye and for nerve sheaths.
Nicotinic acid (niacin)	Needed for the metabolism of food, the maintenance of healthy skin, nerves and the gastrointestinal tract.; part of enzymes and coenzymes required for oxidation of glucose and synthesis of proteins, fats, and nucleic acids.
Pantothenic acid	Part of coenzyme A required for oxidation of carbohydrates and fats; needed for the production hormones.
Vitamin B6 (pyridoxine)	Coenzyme required for synthesis of proteins and various amino acids, for conversion of tryptophan to niacin, for production of antibodies, and for nucleic acid synthesis; used in the production of red blood cells and in the reactions involved in the metabolism of amino acids; needed for the breakdown of carbohydrates, proteins, and fats.
Vitamin B12(cyanocobalamin)	Part of coenzyme required for synthesis of nucleic acids and for metabolism of carbohydrates; plays role in myelin synthesis required for normal red blood cell production—good for cell reproduction , especially in bone marrow (site of rbc production); good for healthy nerve tissue.
Folic Acid (folacin)	Coenzyme required for metabolism of certain amino acids and for DNA synthesis; promotes production of normal red blood cells; important in development of fetus; aids in replacing cells and the use of amino acids for genes.
Biotin	Coenzyme required for metabolism of amino acids and fatty acids and for nucleic acid synthesis; possibly aids healthy skin.
Vitamin C (ascorbic acid)	Required for collagen production, conversion of folacin to folinic acid, and metabolism of certain amino acids; promotes absorption of iron and synthesis of hormones from cholesterol; helps protect vitamins A and E and fatty acids from oxidation; works to promote healthy arteries, bones and teeth, the immune system, and helps in the healing of wounds and burns; can be beneficial in the treatment of iron deficiency anemia.