Biological Chemistry - Berezov T. T., Korovkin B. F. 1998

Vitamins
Classification of Vitamins

The modern Classification of Vitamins is not entirely adequate. It is based on their Physical and Chemical properties (such as solubility) or chemical nature, although letter designations are still widely used today. Depending on their solubility in non-polar organic Solvents or aqueous media, vitamins are divided into fat-soluble and Water-soluble. In the classification given below, along with the letter designation, the main biological effect is indicated in parentheses—sometimes with the prefix "anti-" to denote the vitamin's ability to prevent or treat the onset of a specific deficiency disease—followed by the official chemical nomenclature name of each vitamin.

Fat-soluble vitamins

1. Vitamin A (antixerophthalmic); retinol

2. Vitamin D (antirachitic); calciferols

3. Vitamin E (antisterility, reproduction vitamin); tocopherols

4. Vitamin K (antihemorrhagic); naphthoquinones

Water-Soluble Vitamins

1. Vitamin B₁ (antineuritic); thiamine

2. Vitamin B₂ (growth vitamin); riboflavin

3. Vitamin B₆ (antidermatitic, adermin); pyridoxine

4. Vitamin B₁₂ (anti-anemic); cyanocobalamin; cobalamin

5. Vitamin PP (antipellagra, niacin); nicotinamide

6. Vitamin B_с (anti-anemic); folic acid

7. Vitamin B₃ (antidermatitic); pantothenic acid

8. Vitamin H (antiseborrheic, bacterial, Yeast, and fungal growth factor); biotin

9. Vitamin C (antiscorbutic); ascorbic acid

10. Vitamin P (capillary-strengthening, permeability vitamin); bioflavonoids

In addition to these two main groups, There is a diverse group of chemical substances—some synthesized within the body—that possess vitamin-like properties. In humans and certain animals, these compounds are collectively referred to as vitamin-like factors. They include choline, Lipoic Acid, vitamin B₁₅ (pangamic acid), orotic acid, Inositol, ubiquinone, Para-aminobenzoic Acid, carnitine, linoleic and linolenic acids, Vitamin U (anti-ulcer factor), as well as various growth factors for birds, rats, chicks, and tissue cultures. A newly discovered factor termed pyrroloquinoline quinone has also been identified. While its coenzyme and cofactor properties are known, its specific vitamin Functions are not yet fully understood (see "Vitamin-like substances" below). Since typical clinical manifestations of avitaminosis are relatively rare, a detailed description of hypo- and avitaminosis symptoms is hardly necessary. Instead, we will focus on the biological roles of those vitamins whose Mechanisms of action have already been elucidated.

Class="center">Table 7.1. Nature of the Biocatalytic Function of Vitamins

Table 7.1 summarizes current knowledge regarding daily requirements, active form structures, and the physiological roles of vitamins.