Types of Vitamins and Their Functions
Food Facts

Types of Vitamins and Their Functions

Vitamins are any group of substances found in very small amounts in most foods. A well-balanced, varied diet contains all the vitamins normally needed for health. Vitamins in excess of what the body needs do not increase health or well-being, and may actually produce illness. A poor diet cannot be corrected simply by taking vitamins in concentrated form.


Types of Vitamins and Their Functions


Vitamin A

It plays a part in the chemical reactions that take place in the retina of the eye when it is stimulated by light. In other words, vitamin A is essential to vision. Lack of vitamin A can lead to Xerophthalma and to poor vision in dim light (night blindness)



Vitamin A is found in all animal tissues, but it is especially abundant in fish-liver oil. An indirect source of vitamin A is a substance called Carotene, which the body can convert into vitamin A. Carrots and orange-colored fruits and vegetables contain plentiful amounts of carotene.



If pure vitamin A concentrate is taken daily in very large amounts, it can lead to severe disorders of the nervous system, bones and other tissues.


Vitamin B (Vitamin B Group)

This contains a number of vitamins that are usually known by their chemical names. They include thiamine, riboflavin, niacin, pantothenic acid, folic acid, and vitamin B12. They are described below:


Thiamine (or vitamin B1) is found in many foods. Yeast, wheat germ, pork and liver are especially good sources. Beriberi is due to thiamine deficiency as are some of the symptoms that accompany chronic alcoholism


Riboflavin (or vitamin B2) occurs chiefly in milk, egg white, liver and leafy vegetables. Skin disorders, inflammation of the tongue, and cracking at the corners of the mouth may result from lack of sufficient riboflavin



Niacin (or nicotinic acid) is abundant in yeast, wheat germ and organ meat (liver, kidney, heart and brain). Milk contains large amounts of substance that the body readily converts to niacin. Pellagra is due to severe niacin deficiency


Pantothenic acid is plentiful in liver, kidney, egg yolk and fresh green vegetables. No abnormal condition are known to result from lack of this vitamin.


Folic acid, also known as PGA (pteroylglutamic acid) is plentiful in liver, yeast, mushrooms and green leafy vegetables. This vitamin is essential to a number of chemical reactions that take place in the nucleus of every cell in the body. Alcohol and several other substances, including some antibiotics, interfere with the utilization of folic acid. Some kinds of anemia, sprue and chronic alcoholism are associated with folic acid deficiency.


Vitamin B12 is abundant in liver and other organ meat. It plays a part in the formation of red blood cells or erythrocytes.

In normal, healthy people, most of the vitamin B12 needed is absorbed in the digestive system. People with pernicious anemia are unable to absorb this vitamin properly, and the disease is controlled by vitamin B12 concentrate.


Vitamin C

It is also known as Ascorbic Acid. It is abundant in many fruits and vegetables, especially in oranges, lemons and tomatoes. It is often added to canned fruit juices and fruit drinks. Lack of vitamin C causes Scurvy. 

Since the body cannot store vitamin C, foods containing it should be eaten daily to maintain good health.


Vitamin D

It is sometimes called the sunshine vitamin because it is produced in the skin when a person is outdoors in the sun. It plays a part in bone formation and the utilization of calcium. Rickets in children is associated with lack of sufficient vitamin D.

Commercially prepared foods, such as milk and bread, are often enriched with vitamin D. If pure vitamin D concentrate is prescribed by your doctor, do not take more than she orders. Deposits of calcium in the kidneys, heart, and other soft tissues can result from taking massive doses of vitamin D


Vitamin E

It is present in most foods and very abundant in vegetable oils. Vitamin E is a prominent antioxidant and this special vitamin is vital for skin health and beauty.


Vitamin K

It is very abundant in green leafy vegetables. It is also formed by bacteria normally present in the intestine. It has an essential role in the clotting of blood.