Vitamin A does quite a lot to help the body run right. Generally speaking, there are two types of the vitamin, both of which play an important role in maintain good health. Some of the areas where vitamin A plays a role are:
• Encourages healthy surface linings of the eyes, and the intestinal, urinary, and respirator tracts.
• Regulation of the immune system
• Prevents or diminishes infections through the production of white blood cells
• Assists both the skin and mucous membranes ward off foreign invaders such as bacteria and viruses.
One of the two types of vitamin A is found in animals and is termed “preformed vitamin A”. The body absorbs this in the form of retinol which is one of the more useful forms of the vitamin. Our bodies make both retinal and retinoic acid from the retinol.
Typical Sources are:
• Beef liver
• Chicken liver
• Cheddar cheese
• Whole milk
The other type is termed “provitamin A” cartinoid. The NIH definition of “cartinoid” is:
“A substance that makes certain fruits and vegetables yellow, orange, or red. Some carotenoids (beta-carotene, alpha-carotene, and beta-cryptoxanthin) can be made into vitamin A by the body. Other carotenoids (lycopene, lutein, and zeaxanthin) cannot be converted by the body. All carotenoids are antioxidants.”
Some sources of Provitamin A Cartinoid:
• Romaine Lettuce
Vitamin A Deficiency
Across the world, vitamin A deficiency is seen in developing countries but vary rarely in developed nations. Most frequently, a deficiency is because of dietary restrictions and excess alcohol. One estimate is that more than a quarter million undernourished children go blind annually from a lack of A vitamin.
A lack of vitamin A also decreases the body’s ability to fight off infections so many more deaths can be attributed to diseases like measles that are merely inconvenient in more developed areas.