Vitamins are complex organic substances that are needed in very small amounts for many of the processes carried out in the body. Vitamin deficiency diseases are rare in the UK, but still occur in some parts of the world. Vitamin A is essential for normal growth and development.
Deficiency leads to poor vision in dim light and eventually to blindness.
Excess retinol can be toxic and may be particularly dangerous for the unborn child. It is for this reason that women who are pregnant, or who might become pregnant are advised not to take high-dose vitamin A supplements unless they are advised to do so by a health professional. Liver and liver products may contain a large amount of vitamin A, so these should also be avoided. Retinol is found in liver, whole milk, cheese and butter. Carotenes are found in milk, carrots, dark green leafy vegetables and orange coloured fruits, eg mango and apricots.