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.