Vitamin A

Vitamin A is in the family of fat-soluble vitamins. Retinol is one of the most active, or usable, forms of vitamin A, and is found in animal foods such as liver and eggs.

Top sources of vitamin A include:

liver
carrots, green and yellow vegetables
eggs, milk, and other dairy products
yellow fuits

Vitamin A is involved in the formation and maintenance of healthy skin, hair, and mucous membranes. It helps us to see in dim light and plays an important role in vision, bone growth, tooth development reproduction, cell division and cell differentiation, which is the process by which a cell decides what it is going to become. It helps maintain the surface linings of the eyes and the respiratory, urinary, and intestinal tracts. When those linings break down, bacteria can enter the body and cause infection. It also helps maintain the integrity of skin and mucous membranes that function as a barrier to bacteria and viruses.

Vitamin A helps regulate the immune system. The immune system helps prevent or fight off infections by making white blood cells that destroy harmful bacteria and viruses. Vitamin A may help lymphocytes, which is a type of white blood cell that fights infections, function more effectively. It's recommended that women consume 800 mcg and men consume 1000 mcg of vitamin A daily.

Fat-soluble vitamins, such as vitamin A, are stored in the fat tissues of the body for a few days to up to six months. If you get too much of a fat-soluble vitamin, it can be stored in your liver and may sometimes cause health problems. Some people take mega-doses of fat-soluble vitamins, which can lead to toxicity.

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Note that the contents here are not presented from a medical practitioner, and that any and all health care planning should be made under the guidance of your own medical and health practitioners. The content within only presents an overview of the topics and does not replace medical advice from a professional physician.

Where I have listed the nutritional contents of foods, that information is from the U.S. Department of Agriculture, Agricultural Research Service. 2005. USDA National Nutrient Database for Standard Reference, Release 18. Nutrient Data Laboratory Home Page.

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