Vitamin A can control or modify creating acne lesions process. One of stages is improper shedding of skin cells. Vitamin A helps improve removing of dead skin cells and reduces risk of clogged pores development. Clogged pores are required for acne development.

Carotenoids are a natural fat-soluble pigments. Carotenoids can be found in fruits, vegetables and some animal products. They are necessary for the photosynthetic process.

Vitamin A exists in several relative forms:

• retinol (alcohol, Vitamin A1)
• degidroretinol (Vitamin A2)
• retinal (retinen, vitamin A-trichloroacetaldehyde)
• retinol acid (vitamin A acid)
• ethers of these substances and their isomers

Following foods are rich in vitamin a:

According to Recommended Dietary Allowance (RDA) (http://www.nal.usda.gov/fnic/etext/000105.html) recommended daily intake of Vitamin A is 5000 IU for man, 4000 IO for woman.
5000 IU is approximately 3 mg of beta carotene. 4000 IU is 2.4 mg beta carotene.

Daily upper limit of retinol is 3000 mg (3g or 10000 IU).

Upper limit doesn't refer to carotene forms (from dietary source). Carotene forms (foods of plant) are not toxic.

Top Vitamin A foods are:

• liver
• sweet potatoes
• carrots
• mangoes
• spinach
• cantaloupe
• dried apricots
• milk
• egg yolks
• mozzarella cheese

Vitamin A deficiency is not common disease. But it's most common in underdeveloped countries.

Vitamin A deficiency can lead to blindness.

Symptoms:

• Reduced night vision
• Night blindness
• Dry eyes
• Eye inflammation

Causes:

Most common cause of deficiency of Vitamin A is insufficient intake of foods high in vitamin A or carotene.

Less common causes are:

Vitamin A (Retinol) - a fat-soluble vitamin. It exists in several forms: retinol, retinal and retinic acid.
Provitamins (prescures) of Vitamin A are carotenoids - animal form of Vitamin A. Carotenoids can be found in foods of plant.

Vitamin A is necessary for vision, growth, development, healthy skin, hair, immunity, reproduction and more.

Was discovered by Lafayette Mende, Thomas Osborne and Elmer McCollum in 1917.