Vitamin A is fat-soluble. It requires fats as well as minerals to be properly absorbed by your digestive tract. It can be stored in your body and it does not need to be replenished every day. It occurs in two forms. One is preformed vitamin A, called retinol, and can be only found in foods of animal origin. The other one is provitamin A, another name of carotene. It is the food for both plant and animal origin.
Vitamin A is measured in USP Units (United States Pharmacopeia), IU (International Units), and RE (Retinol Equivalents). (See section 168.) 1,000 RE (or 5,000 IU) is the recommended daily dosage for adult males to prevent deficiency. For females, it is 800 RE (4,000 IU). During pregnancy, the new RDIs and RDAs do not recommend an additional intake of the vitamin, but for nursing mothers, an additional 500 RE is suggested for the first six months and an additional 400 RE for the second six months.
There is no formal RDI/RDA for beta-carotene because it is not officially recognized as an essential nutrient. But, usually, 10,000 IUs to 15,000 IUs of beta-carotene are needed to meet the RDI/RDA for vitamin A.
WHAT VITAMIN A CAN DO FOR YOU:
- Counteract night blindness, weak eyesight, and many eye disorders (It permits the formation of visual purple in the eye).
- Build resistance to respiratory infections.
- Aid in the proper function of the immune system.
- Shorten the duration of diseases.
- Keep the outer layers of your tissues and organs healthy.
- Help in the removal of age spots.
- Promote growth, strong bones, healthy skin, hair, teeth, and gums.
- Help treat acne, superficial wrinkles, impetigo, boils, carbuncles, and open ulcers when applied externally.
- Aid in the treatment of emphysema and hyperthyroidism.
Deficiency results in xerophthalmia and night blindness. Deficiency often occurs as a result of chronic fat malabsorption. It is most commonly found in children under five years, usually because of insufficient dietary intake.