But what is vitamin A, what does it do and which foods contain it?
Here’s what you need to know.
What is vitamin A?
Vitamin A, also known as retinol, has several important functions, including:
- helping your body’s natural defence against illness and infection (the immune system) work properly
- helping vision in dim light
- keeping skin and the lining of some parts of the body, such as the nose, healthy
The total vitamin A content of a food is usually expressed as micrograms (µg) of retinol equivalents (RE).
The amount of vitamin A adults aged 19 to 64 need is:
- 700 µg a day for men
- 600 µg a day for women
You should be able to get all the vitamin A you need from your diet and any vitamin A your body does not need immediately is stored for future use, which means you do not need it every day.
According to the World Health Organisation (WHO), “vitamin A deficiency results from a dietary intake of vitamin A that is inadequate to satisfy physiological needs”.
The deficiency may be exacerbated by high rates of infection and is common in developing countries, but rarely seen in developed countries.
Vitamin A deficiency is a public health problem in more than half of all countries, especially those in Africa and South-East Asia, with the most severe effects of this deficiency being seen in young children and pregnant women in low-income countries.
WHO says that night blindness is one of the first signs of vitamin A deficiency, as in its more severe forms, vitamin A deficiency contributes to blindness by making the cornea very dry, which then damages the retina and cornea.
Vitamin A deficiency can also diminish the ability to fight infections and can increase children’s risk for respiratory and diarrhoeal infections, decrease growth rates and slow bone development.
Which foods are good sources of vitamin A?
Good sources of vitamin A include:
- oily fish
- fortified low-fat spreads
- milk and yoghurt
- liver and liver products such as liver pâté – this is a particularly rich source of vitamin A, so the NHS says you may be at risk of having too much vitamin A if you have it more than once a week. If you’re pregnant you should avoid eating liver or liver products).
You can also get vitamin A by including good sources of beta-carotene in your diet.
Beta-carotene gives yellow and orange fruit and vegetables their colour. It’s turned into vitamin A in the body, so it can perform the same jobs in the body as vitamin A.
The main food sources of beta-carotene are:
- yellow, red and green (leafy) vegetables, such as spinach, carrots, sweet potatoes and red peppers
- yellow fruit, such as mango, papaya and apricots