Function of Vitamin A in the Body

Vitamin A performs a number of vastly different functions in the body every day. Some of these daily functions involve vision, gene transcription, bone and tooth development and reproduction. Vitamin A is also a very active antioxidant which helps prevent cancer and heart disease. It is a fat soluble vitamin that can be ingested directly from meat and dairy foods or indirectly from fruits and vegetables in the form of beta carotene. Once inside the body, beta carotene is transformed into Vitamin A. Because of it's pivotal function in vision and gene transcription, some of the earliest signs of deficiency of vitamin A include diminished night vision and poor hair and mucus membrane quality.

Vitamin A's important function related to vision involves the replacement of a neural signaler. When light hits the retina, a chemical found on the retina splits into two. One part leaves and ultimately produces the nerve signal that travels to the brain. Vitamin A is necessary in the eye to replace the part of the molecule that splits away from the retina. When there is a vitamin A deficiency, the part of the molecule that split away is not replaced, and that area of the retina can no longer signal to the brain the presence of light. This first becomes noticeable in dim light situations, but can also lead to total blindness

Vitamin A is also important in DNA transcription, which is when the DNA template is used to produce RNA which is later used to produce a specific protein. Vitamin A insides the cell ensures that the DNA is properly interpreted and also has a role in the rate of production of RNA. Because of Vitamin A's function with regard to DNA transcription, a deficiency will often cause poor skin and hair quality.

Vitamin A has a major function with regard to bone and tooth development. When teeth are forming, Vitamin A has a regulatory role in the formation of enamal. A deficiency of Vitamin A will cause the layer of enemal in the teeth to be too thin. Vitamin A is also necessary on a daily basis to strengthen bones.

Another function of DNA is in the production of mucous that is used to coat and protect the lining of the respiratory and digestive tract. In the respiratory tract, mucous is important because it traps bacteria and other particles that try to enter the body. In the digestive tract, mucous is used to both protect the lining of the stomach, and to aid in the movement of food during digestion. Vitamin A has another important function inside the stomach, and that is it's role in gastric acid production. Gastric acids are necessary to break down foods so that nutrients can be extracted easier.

Vitamin A, because of it's function in gene transcription, is needed by the body for muscle development and strengthening. Lack of vitamin A will prevent the muscles from repairing themselves after a day of exercise. Individuals doing excessive training every day often take daily supplements of vitamin A to ensure the nutritional needs caused by their workout is being met.

The function of muscle building is also very important in children as a deficiency of vitamin A will result in the child being shorter and having less muscle mass then their peers. Maintaining the recommended daily amount of vitamin A in the diet helps to ensure that the child will grow at the proper rate.

Finally, Vitamin A is a strong antioxidant that the body uses to protect DNA during cellular division. During DNA replication, the presence of free radicals can cause improper cellular division that can result in the development of cancer. Vitamin A reacts with the free radicals and prevents them from interfering with DNA replication. Vitamin A and other antioxidants also act in the bloodstream to prevent cholesterol from forming plaques, which lead to heart disease.