Vitamins

Vitamins are organic chemical compounds which are exogenous for the human body. Exogenous means that they are essential for the correct functioning of human body and that they have to be supplied with food, because the body itself cannot produce them. The only exception is vitamin D, which is produced inside skin cells under the impact of UV light.

The name comes from latin words vita (life) and amina (chemical compound which contains an amine group). In reality not all vitamins have an amine group, e.g. vitamin D is a steroid. The name was invented by the Polish biochemist Kazimierz Funk in 1912. Kazimierz Funk is also the discoverer of vitamins – in 1912 he isolated thiamine, which is vitamin B1. Vitamins are not typical nutrients – they perform a regulatory function in metabolic processes inside the human body.

From the point of view of chemistry, vitamins belong to many different groups of organic compounds. Only their importance for life allows to classify them under one name. For that reason traditionally vitamins are divided into:

• soluble in water: vitamin C (ascorbic acid), vitamin B1 (thiamine), vitamin B2 (riboflavin), vitamin B3 (niacin, vitamin PP, nicotinic acid, nicotinic acid amide), vitamin B5 (pantothenic acid), vitamin B6 (pyridoxin, adermine), vitamin B7 (biotine, vitamin H), vitamin B9/B11 (folic acid), vitamin B12 (cyanocobalamin), vitamin P (mixture of flavonoid derivatives like hesperidine or rutin).
• soluble in fats: vitamin A (retinol and its derivatives), vitamin D (cholecalciferol and its derivatives), vitamin E (tocopherol), vitamin K (phylloquinone, menadione).

Vitamin K is responsible for correct blood coagulation. Supplementation of vitamin K is recommended for breast-fed neonates and infants. In accordance with the expert group’s recommendations related to prevention of bleeding connected with vitamin K deficiency, breast-fed neonates and infants should receive 25 micrograms of vitamin K per day starting from the 2nd week till the end of the 3rd month of life.

Vitamin D is essential for correct bone tissue growth. It supports the process of calcium and phosphorus absorption from food in accordance with the needs of the body. Although vitamin D is produced in the skin, sometimes its supplementation is essential. In accordance with the expert group’s recommendations related to prevention of vitamin D deficiency, breast-fed neonates born prematurely and at term should receive 400 IU (10 micrograms) per day.