What is Vitamin A?

Vitamin A is actually a fat soluble combination of compounds that is necessary to keep us healthy in many different ways. Eyesight, proper cell division and differentiation, and reproduction are all bodily functions that Vitamin A plays a role in. In addition, Vitamin A helps to regulate the human immune system by performing such duties as fighting infection by aiding the body in the creation of white blood cells.

The skin and mucous membranes are also affected by Vitamin A’s promotion of their surface linings. This can help to provide a barrier for blocking out harmful infections and bacteria.

There are several types of different Vitamin A compounds, with the primary source being retinol. Retinol is one of the types of Vitamin A which can be most readily absorbed by the body. Also commonly referred to as preformed Vitamin A, this nutrient can be found in whole milk and other animal products such as eggs and liver. The other source of Vitamin A is a chemical compound known as carotenoid.


Carotenoids are dark pigments which exist in certain plants which can be converted into Vitamin A by our bodies. You may have heard of some of the carotenoids; beta carotene, lutein, lycopene, and alpha carotene represent some of the more commonly consumed carotenoids, with beta carotene being the most valuable source of retinol of all of the carotenoids.

Beta carotene can be found in food sources such as carrots, spinach, mangos, papayas, oatmeal, peas, and tomatoes. Carotenoids account for as much as 26 to 34 percent of the Vitamin A taken in by the average person.

The Institute of Medicine has established some guidelines for what the average person’s daily Vitamin A intake should be. The Recommended Dietary Allowance, or RDA, for a male adult’s Vitamin A intake is 900 milligrams. In adult females, 700 milligrams is the recommended dose. A lack of Vitamin A can result in a host of side effects. While Vitamin A deficiencies are not usually found to occur in countries such as the United States, third world countries often face these dangerous problems.

Between 250 thousand and 500 thousand children worldwide go blind per year due to a lack of this important nutrient. In addition, a lack of Vitamin A can cause the body to not fight infections as well as it should. Respiratory infections and diarrhea are common among those with a Vitamin A deficiency, and stunted growth and bone development may occur if the problem is long-term.

One of the first signs of a Vitamin A deficiency is night blindness. If this occurs, it is important to ensure that you are eating a good number of Vitamin A rich foods. One must also take care to not intake too much Vitamin A; in high levels, it is toxic, and can cause such problems as birth defects, abnormalities of the liver, and reduced bone density.

For these reasons, it is important to carefully monitor your Vitamin A intake, ensuring that you don’t get too much or too little. Beta carotene supplements are available for those who cannot consume enough Vitamin A-rich foods for any reason.