Vitamins are organic substances necessary in very small amounts to direct different processes within living cells. Even though vitamins offer no energy benefits to the body directly, they do help set free the energy stored in carbohydrates, proteins, and fats. Thus, most vitamins help chemical reactions to take place. The human body does not produce most of the vitamins it requires and must obtain them from foods.
When taken as a dietary supplement in the daily diet, they help balance out the deficiencies of improper eating habits, overcooked foods, and non-nutritive processed foods. Vitamins are also critical in the production of red blood cells and the protection of the nervous, skeletal, and immune system.
Humans require 13 essential vitamins.
Four are fat-soluble vitamins (Vitamins A, D, E, and K), and the remaining nine are water-soluble (Vitamins C and the eight B-complex vitamins: thiamin, riboflavin, niacin, vitamin B-6, folate, vitamin B-12, biotin, and pantothenic acid).
Solubility refers to how a vitamin is absorbed, transported, and stored in the body. The water-soluble vitamins are absorbed directly into the bloodstream. Extra water-soluble vitamins are removed by the kidneys and excreted in the urine. Fat-soluble vitamins are usually transported in the blood by special proteins and excess gets stored in the fatty tissues of the body rather than excreted. » Read more: Vitamin Benefits, Sources and Deficiency
