Vitamin A comes as pre-formed vitamin A (often called retinol) and as provitamin A carotenoids (such as alpha-carotene and beta-carotene) which form vitamin A in the body. Because of the different forms, vitamin A requirements are expressed in terms of ‘retinol equivalents’.
Recommended dietary intake (RDI) for vitamin A (in retinol equivalents) per day:
- women 700 micrograms (mcg)
- men 900mcg
Why we need it?
Vitamin A plays a role in vision, reproduction, cellular differentiation, gene expression, immune function and growth. It’s also associated with the prevention of cancer and heart disease.
Can we get too much?
Pre-formed vitamin A can be toxic at very high levels, especially in unborn children. While high intakes of beta-carotene may cause skin to yellow, it has not been associated with toxicity.
How to get it?
Pre-formed vitamin A is generally found in fats in dairy products, liver and some fatty fish. The carotenoids are found in plants, mainly dark-green leafy vegetables and some yellow and orange-coloured fruits and vegetables.
Each of these foods provides around 350mcg vitamin A (about half the daily requirement for a woman)
- 1/2 carrot
- 2 red capsicums
- 5 eggs
- 1 1/2 cups raw (or 1/3 cup cooked) spinach or silver beet
- 1 teaspoon cooked chicken liver
- 1/3 cup baked pumpkin