What is it?
Vitamin A is a fat soluble vitamin. Carotenes, which are closely related to Vitamin A (particularly beta-carotene), can be converted into this vitamin in our bodies which is why they are sometimes referred to as Provitamin A.
What does it do?
- Eye sight – Vitamin A is required for the manufacture of light sensitive pigments found in the retina at the back of the eye. These pigments are especially important for night or low-light vision. So carrots really can help you see in the dark (but only if you have a Vitamin A deficiency)!
- Skin – Vitamin A is important for maintaining healthy skin, and also healthy internal membranes within the body that not just on the outside of our bodies but also all the internal membranes.
- Immunity – Part of the job of our immune systems is to protect us from external 'agents', viruses, infections, bacteria etc. Our skin and mucus membranes (eg. gut, respiratory tract etc.) are part of this system as they form a physical barrier against these external invaders. Vitamin A helps to maintain their integrity and strength.
- Immunity – vitamin A is thought to stimulate the activity of other components of the immune system including, antibody and anti-tumour activity, and the action of white blood cells.
- Antioxidant activity – the antioxidant capabilities of vitamin A and especially of it's precursor carotenes can offer some protection against certain cancers, particularly those of the digestive & respiratory systems.
- Poor night vision
- Poor immune function, i.e frequent colds and infections
- Skin problems including, dry skin, acne, dandruff, mouth ulcers.
- Recurrent cystitis and thrush
Recommended Daily Amount (RDA)
Children 350-500μg RE
(1μg RE = 3.3IU)
Therapeutic amounts are generally higher than the RDAs above, however, there are safety issues associated with higher doses (see below). Higher doses should be considered in conjunction with a healthcare practitioner, although higher doses of beta-carotene are relatively safe.
Organ meats including liver and kidney
Dairy products including butter and whole milk
Carotenes (Provitamin A)
Dark green leafy vegetables, spinach, kale, cabbage etc.
Orange and yellow fruits and vegetables, including (but not exclusively) carrots, apricots, pumpkin, sweet potato, apricots etc.
There has been some research which links excessive Vitamin A supplementation to birth defects so pregnant women or women of a childbearing age are advised to avoid Vitamin A supplementation.