By Professor Andrew Tomkins.

It has been known for many years that Vitamin A deficiency can cause blindness. In the early stages, the individual complains of not being able to see well at night (night blindness). As the deficiency develops, the lining of the eye becomes dry and cloudy. Eventually, small ulcers may develop and unless vitamin A is taken quickly, the eye is permanently damaged. Vitamin A deficiency is often brought about by illness, particularly diarrhoea and measles, and is especially likely to occur in severely malnourished children. Fortunately, urgent treatment with a capsule containing 200,000 iu of Vitamin A, taken by mouth, will clear the problem up quickly.

Deficiency of Vitamin A causes small ulcers to develop on the cornea (lens) of the human eye. The ulcers may appear pale green.

Each of the capsules contains 200,000 iu of Vitamin A. As well as relieving the corneal ulcers shown above, they can significantly reduce the mortality from measles in young children. Just one tablet a day for two days is sufficient.

Varying results

It is also realised that Vitamin A affects the ability of the body to fight infection (it may influence the strength of the lining of the intestinal and respiratory tract). People have become more interested in the potentially important effect of Vitamin A on the immune response of the body to infection.

There have been several studies which have shown reduction in mortality, probably from infectious disease, among children who receive 200,000 iu every four to six months. However, there have been some equally well-performed studies which show that supplementation does not necessarily improve mortality! It may be that different parts of the world have different levels of severity of Vitamin A deficiency, and so what is good for one population may not necessarily be so effective in another.

Whether Vitamin A should be given as capsules (assuming these can be regularly supplied) or whether Vitamin A intake should be increased by greater efforts in encouraging horticulture and good diet (plenty of dark green leafy vegetables) – should be a national or local decision. It will depend on how severe the problem is. The costs of purchasing and distributing capsules also have to be considered.

Give Vitamin A to a child with measles

What is quite clear however, is that children with severe measles do benefit from having a capsule of Vitamin A. Two studies, one in South Africa and one in Tanzania, have shown that childhood mortality from measles can be reduced by about 30% if a capsule of 200,000 iu is given on each of two successive days. In fact, WHO recommends that this should be the routine management of measles where there is obvious Vitamin A deficiency or where the proportion of children dying from episodes of measles exceeds 1%. We will try and keep you informed as it becomes clearer on what to do about Vitamin A in the general community.

Encourage mothers to add a mixture of dark green leafy vegetables to their children’s diet to increase Vitamin A intake.