Vitamin A is a fat-soluble vitamin made up of a group of compounds called, retinol, retinal, carotenoids and carotene. It main active form is aldehyde retinal which is essential in the formation of rhodopsin. Rhodopsin is a light-sensitive pigment in the rod cells of the eye. The pigment is made up of retinal and is attached to opsin. Once, light enters the eye and hits the rod cell, rhodopsin seperates back into two components and sends an image to the brain. Now with all that science and techie talk, what does this have to do with Vitamin A?

This is why we are told that vitamin A is important to good eyesight and prevents night blindness. A Vitamin A deficiency can cause keratomalacia, a condition wherein the cornea is dry and ulcerated, which manifests as night blindness, photosensitivity and swollen eyelids. Xerophthalmia, another vitamin A deficiency, is also manifested by dryness of the conjunctiva and cornea.

It has been mentioned that vitamin A is a fat-soluble vitamin and so it can be stored in the body over long periods of time. The extra vitamin A is stored in liver and has a half-life of 200 – 300 days. So if the liver has a disease condition, the storage of vitamin A is lessened. An overdose of vitamin A can also be detrimental as the recommended daily allowance is 4- 5000 IU.

Early indication of vitamin A overload is dry skin and itching. A severe form of vitamin A deficiency was first seen from polar explorers who fed on polar bear liver which had high vitamin A content. This caused dizziness, vomiting, nausea and headache which are classic manifestations of vitamin A toxicity.

Since vitamin A is from a group of compounds that include carotenoids, it has been an effective means of the treatment of certain skin diseases such as photosensitivity that also occur in systemic lupus erythematosus, an auto-immune disease. In this diseased state, once skin is exposed to light, it can cause urticaria, acute burns and skin lesions (ouch). Beta-carotene, which is a member of the carotenes, work together with vitamin A as an antioxidant that stops oxidation of fats or lipids in cells and protect the skin from sunlight.

Vitamin A should be included in the diet by eating foods such as carrots, butter, spinach, egg yolks, liver and other yellow fruits and vegetables rich in beta-carotene. Vitamin A can also be purchased as a food supplement at local stores that sell vitamins and minerals. Overall, vitamin A and beta-carotene are powerful antioxidants that benefit your health by achieving healthy eyes and good skin.

Antonio Dannes