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Discovered in 1913 by Elmer McCollum and M. Davis, Vitamin A was the first of the fat soluble vitamins to be identified.

Fat soluble vitamins are dissolved in dietary fats and then absorbed into the body from the small intestines. Needed in small amounts by the human body, vitamin A, and the other fat soluble vitamins, are stored in the liver and fatty tissues known as the adipose tissues.

Vitamin A is an essential nutient to the human body. It is needed for good vision, cell division and differentiation, bone growth and reproduction. It also plays key roles in regulating the immune system and promoting healthy linings in the eyes and intestinal, respiratory and urinary tracts.

Generally, vitamin A is divided into two categories depending upon the food source. The two sources of vitamin A found in nature are plants and animals.

When the food source is animal, the vitamin A is called preformed vitamin A. It is absorbed into the body as a type of retinol which is the form of vitamin A that is the most active. The body can also change retinol into retinoic acid or retinal which are both usable, or active, forms of this important vitamin. Animal sources of vitamin A include:

• Meat
• Fish
• Eggs
• Whole milk
• Cheese
• Fish-liver oil
• Fortified skim milk

Many rich, dark colored vegetables and fruits are the source of vitamin A found in plants. This form of vitamin A, known as provitamin A, carotene or beta-carotene, is water soluble and is not stored in the body. The richer and darker the color of the fruit or vegetable, the more beta-carotene it contains. Several excellent sources of beta-carotene include:

• Carrots
• Sweet potatoes
• Pumpkins
• Winter squash
• Cantaloupe
• Dark green leafy vegetables
• Broccoli
• Pink grapefruit
• Apricots

The beta-carotene in these colorful fruits and vegetables is converted in the body to retinol for use.

Conclusion

Vitamin A, although needed in small amounts, is a nutrient that is essential for a healthy functioning body.