vitamin
definition of vitamin
1. a nutrient that the body needs in small amounts to function and maintain health. Examples are vitamins A, C, and E.1
vitamin a
definition of vitamin a
1. a general term for a group of compounds that includes provitamin A carotenoids (found in foods that come from plants) and retinol (preformed vitamin A found in foods that come from animals). The body can use retinol to make retinal and retinoic acid (other forms of vitamin A). Vitamin A plays an important role in vision, bone growth, reproduction, immunity, cell development, and skin health. Vitamin A is found in some foods, including eggs, liver, fortified milk, cheese, leafy green vegetables (such as spinach, kale, turnip greens, collards, and romaine lettuce), broccoli, dark orange fruits and vegetables (such as apricots, carrots, pumpkin, sweet potatoes, papaya, mango, and cantaloupe), and red bell pepper.1
vitamin b12
definition of vitamin b12
1. a group of chemical compounds that contain cobalt and are needed for certain chemical reactions in the body. Vitamin B12 is involved in maintaining healthy nerve cells and red blood cells. It is needed to make DNA (the genetic material in all cells), and is required for the metabolism (chemical changes that take place in the tissues to produce energy and the basic materials needed by the body) of carbohydrate, fat, and protein. Also called cobalamin. For more information see the NIH Office of Dietary Supplements Vitamin B12 fact sheet.1
vitamin b6
definition of vitamin b6
1. a group of water-soluble chemical compounds, including pyridoxine, pyridoxal, and pyridoxamine. It is involved in protein metabolism, is needed for the nervous system and immune system to work efficiently, and is needed to make hemoglobin (a molecule within red blood cells that carries oxygen to tissues). It also helps maintain blood glucose (sugar) within a normal range. For more information see the NIH Office of Dietary Supplements Vitamin B6 fact sheet.1
vitamin c
definition of vitamin c
1. a nutrient needed by the body to make collagen (a protein found in cartilage, tendons, ligaments, bone, and blood vessels), to absorb iron from food, and for wound healing. It is an antioxidant and protects cells from free radical damage. Vitamin C is found in some foods including citrus fruits, strawberries, peppers, dark green vegetables, tomatoes, and potatoes. Also called ascorbic acid.1