Carotenoids - beta-carotene

Beta-carotene (provitamin A) is essential for vision, adequate growth, and tissue differentiation. It has strong antioxidant properties that help remove free-radicals and can help protect skin against UV damage. It is essential in the conversion of cholesterol into female estrogens and male androgens.

FOOD SOURCES

Apricots, broccoli, spinach, carrots, melon, papaya, pumpkin, tomatoes, palm oil.

SUPPLEMENTATION

Individuals taking beta-carotene for extended periods of time should also supplement with vitamin E, as beta-carotene may reduce vitamin E levels. Intake of polyunsaturated fatty acids with carotene result in rapid destruction of carotene unless antioxidants are present. An adequate supply of zinc is needed so that the liver can mobilize beta carotene.. Absorption is reduced by strenuous physical activity performed within 4 hours of consumption, excessive consumption of alcohol, excessive consumption of iron, and use of cortisone and other drugs.

SIGNS OF DEFICIENCY

Brittle nails, cirrhosis of the liver, corneal ulcers, diarrhoea, frequent fatigue, loss of a sense of smell, loss of appetite, night blindness, obstruction of the bile ducts, rough, dry, or prematurely aged skin, skin blemishes, softening of bones and teeth, sties in the eye, ulcerative colitis, xerosis.

SIGNS OF TOXICITY

Overdose (25,000 IUs or more) beta carotene can produce liver damage. Large doses lead to anaemia and gout, blurred vision, bone pain, diarrhoea, fatigue, hair loss, headaches, irregular periods, liver enlargement, nausea, vomiting. Prolonged excessive intake results in abnormalities in skin, eyes, and mucous membranes, blurred vision, bone fragility, deep bone pain, enlargement of liver and spleen, reduced thyroid activity, skin rashes, thickening of long bones. If toxicity is detected, the symptoms will disappear in a few days after the vitamin is withdrawn. (An International Unit (IU) of beta-Carotene is equivalent to 0.6 mcg).

DAILY REQUIREMENT

1600-2000mcg.