Vitamin A and Beta-Carotene

Vitamin A is a family of fat-soluble vitamins. Retinol is one of the most usable forms of vitamin A and is found in animal foods such as liver and eggs and in some fortified food products.

Beta-Carotene is the most abundant form of provitamin A and converts to vitamin A as required by the body. 1mg of B-carotene is equivalent to 166 mcg retinol. (A provitamin is a substance that turns into a vitamin via a natural reaction in the body).

750 mcg (micrograms)
or 750 RE (Retinol Equivalents)
or 2500 IU (International Units)
or 4.5 mg Beta-carotene

• Necessary for night vision
• Maintains healthy skin and eyes
• Keeps body linings of lungs and intestines healthy
• Supports sperm production
• May protect against cancer
• Boosts resistance to infection
• Helps bone growth

Signs that you are not getting enough vitamin A include: trouble seeing at night; dry eyes; rough skin; and impaired bone growth. Deficiency also makes linings of digestive and respiratory tracts more vulnerable to infection.

Large amounts of vitamin A (over 50,000 IU daily) taken over a period can be very toxic. Individual tolerance varies. Symptoms include headaches, loss of appetite, dry itchy skin, coarse hair, painful bone swellings, and birth defects if a supplement is taken in pregnancy.

Daily intake of vitamin A should not exceed 7500 mcg (25,000 IU) in adults, 1500 mcg (5000 IU) during pregnancy, and 3000 mcg (10,000 IU) in children.

Beta-carotene only converts to vitamin A as required. It is not toxic, even though large amounts can color the skin. Apart from its role as provitamin A, beta-carotene also acts as an antioxidant. Studies suggest it may have a preventive role in cancer, stroke and heart disease.

A diet rich in beta-carotene and other carotenoids can also help lessen skin damage by the sun's UV rays. If you are in the sun a lot, aim for 10-20mg beta-carotene daily, and of course, cover up and use a good sun screen.

Beta-carotene is just one of hundreds of other carotenoids and probably works best in combination with others.

Beta-carotene is mainly found in deep yellow/orange/red and dark green fruit and vegetables. Aim for at least 6 mg daily.