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Vitamins are classified as either water-soluble or fat-soluble. In humans there are 13 vitamins: 4 fat-soluble (A, D, E, and K) and 9 water-soluble (8 B vitamins and vitamin C). Water-soluble vitamins dissolve easily in water and, in general, are readily excreted from the body, to the degree that urinary output is a strong predictor of vitamin ...
Pantothenic acid is a water-soluble vitamin, one of the B vitamins. It is synthesized from the amino acid β-alanine and pantoic acid (see biosynthesis and structure of coenzyme A figures). Unlike vitamin E or vitamin K, which occurs in several chemically related forms known as vitamers, pantothenic acid is only one chemical compound.
Riboflavin, also known as vitamin B 2, is a water-soluble vitamin and is one of the B vitamins. [3] [4] [5] Unlike folate and vitamin B 6, which occur in several chemically related forms known as vitamers, riboflavin is only one chemical compound.
Because water-soluble B vitamins are eliminated in the urine, taking large doses of certain B vitamins usually only produces transient side effects (only exception is pyridoxine). General side effects may include restlessness, nausea and insomnia. These side effects are almost always caused by dietary supplements and not foodstuffs.
Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, along with numerous other biological functions. [1] [2] In humans, the most significant compounds within this group are vitamin D 3 (cholecalciferol) and vitamin D 2 (ergocalciferol). [2] [3]
Antioxidant activity could be measured simply by placing the fat in a closed container with oxygen and measuring the rate of oxygen consumption. However, it was the identification of vitamins C and E as antioxidants that revolutionized the field and led to the realization of the importance of antioxidants in the biochemistry of living organisms .
Vitamin E is fat soluble, so dietary supplement products are usually in the form of the vitamin, esterified with acetic acid to generate tocopheryl acetate, and dissolved in vegetable oil in a softgel capsule. [3] For alpha-tocopherol, amounts range from 100 to 1000 IU per serving. Smaller amounts are incorporated into multi-vitamin/mineral ...
Thiamine was the first of the water-soluble vitamins to be isolated. [73] The earliest observations in humans and in chickens had shown that diets of primarily polished white rice caused beriberi, but did not attribute it to the absence of a previously unknown essential nutrient. [74] [75]