Function
are a group of substances that are needed for normal cell function, growth, and development. There are 13 essential vitamins. They are:
Vitamin A
Vitamin C
Vitamin D
Vitamin E
Vitamin K
Vitamin B1 (thiamine)
Vitamin B2 (riboflavin)
Vitamin B3 (niacin)
Vitamin B6 (pyridoxine)
Vitamin B12 (cyanocobalamin)
Pantothenic acid (B5)
Biotin (B7)
Folate (folic acid or B9)
Vitamins are grouped into two categories:
Fat-soluble vitamins are stored in the body’s liver, fatty tissue, and muscles.
The four fat-soluble vitamins are vitamins A, D, E, and K. These vitamins are absorbed more easily by the body in the presence of dietary fat. Water-soluble vitamins are not stored in the body. The nine water-soluble vitamins are vitamin C and all the B vitamins.
What Are Vitamins?
Having too little of any particular vitamin may increase the risk of developing certain health issues. A vitamin is an organic compound, which means that it contains carbon. It is also an essential nutrient that the body may need to get from food.
Fat-Soluble And Water-Soluble Vitamins
Vitamins are either soluble, or dissolvable, in fat or water. We describe both types below: Fat-soluble vitamins Vitamins A, D, E, and K are fat-soluble. Water-soluble vitamins Water-soluble vitamins do not stay in the body for long and cannot be stored.
They leave the body via the urine. Because of this, people need a more regular supply of water-soluble vitamins than fat-soluble ones. Vitamin C and all the B vitamins are water-soluble .
Vitamin supplements Many people in the United States take multivitamins and other supplements, though these may not be necessary or helpful, according to research . The Department of Health and Human Services provide up-to-date guidelines detailing the best ways to get enough nutrients from the diet. Fortified foods and supplements may be appropriate in some cases, however, such as during pregnancy, for people with restricted diets, and for people with specific health issues.
Anyone taking supplements should be careful not to exceed the maximum dose, as research shows that taking too much of any vitamin can lead to health problems. Also, some medications can interact with vitamin supplements.
Biological Significance Of Vitamins
Some of the first evidence for the existence of vitamins emerged in the late 19th century with the work of Dutch physician and pathologist Christiaan Eijkman.
In 1890 a nerve disease (polyneuritis) broke out among his laboratory chickens. In 1906–07 British biochemist Sir Frederick Gowland Hopkins observed that animals cannot synthesize certain amino acids and concluded that macronutrients and salts could not by themselves support growth. Because each of these factors had a nitrogen-containing component known as an amine, he called the compounds “vital amines,” a term that he later shortened to “vitamines.” The final e was dropped later when it was discovered that not all of the vitamins contain nitrogen and, therefore, not all are amines.