Vitamin A is a general term for the fat-soluble retinoid, including retinol, retinal, and retinyl esters, depending on whether it is derived from an animal or a plant in the food source.
Vitamin A found in foods obtained from animals is called preformed vitamin A or retinol.
Vitamin A found in fruits and vegetables is called provitamin A carotenoid. Carotenoids are converted to retinol in human cells and exhibit vitamin A activity. Other provitamin A carotenoids include alpha-carotene and beta-cryptoxanthin. The compound that exhibits the most vitamin A activity among carotenoids is beta-carotene.
Excess vitamin A in the body is stored as retinyl esters in the liver.
What are the Benefits of Vitamin A?
The benefits of vitamin A can be listed as follows:
- Vitamin A contributes to normal iron metabolism.
- Vitamin A contributes to the maintenance of normal mucous membranes.
- Vitamin A contributes to the maintenance of normal skin.
- Vitamin A contributes to the maintenance of normal vision.
- Vitamin A contributes to the normal function of the immune system.
- Vitamin A plays a role in cell specialization.
Which Foods Contain Vitamin A?
Foods containing vitamin A are divided into two groups. It is found as retinol in animal-based foods and as carotenoids (beta-carotene being the most active) in plant-based foods. Vitamin A is naturally present in many foods and is also found in some fortified foods such as milk and cereals.
Foods that contain vitamin A include:
- Animal products such as beef liver
- Egg yolks
- Some fatty fish species like salmon
- Green leafy vegetables and other green, orange, and yellow vegetables such as broccoli, carrots, and squash
- Fruits including cantaloupe, apricot, and mango
- Breakfast cereals