Vitamin A (Hansard, 18 October 1990)

§ Mr. Dorrell

Our Department, together with the Ministry of Agriculture, Fisheries and Foods, has been considering evidence which suggests that high levels of vitamin A may cause birth defects.

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The Chief Medical Officer, Sir Donald Acheson, is cautioning women who are, or who may become, pregnant not to take vitamin A supplements except under medical supervision, and as a matter of prudence, not to eat liver or liver products because the high levels of vitamin A found in some samples of animal liver may be harmful.

The Chief Medical Officer has sought expert advice on this question and he has issued the following advice: While there is, at present, no positive evidence that any birth defects have arisen as a result of Vitamin A intakes within the United Kingdom, there have been a small number of case reports from abroad of birth defects in children of women who have taken supplements containing Vitamin A greatly in excess of the recommended daily amount. Worldwide, there has been only one case reported of birth defects in a baby born to a woman who had consumed large quantities of liver every day during her pregnancy. Vitamin A is essential for good health. Pregnant women and nursing mothers have always been advised to make sure they get enough of it in their diet. However, it has recently been suggested that an excess of Vitamin A may cause birth defects. This is why the Committee on Toxicity, reinforced by other experts, has been considering all the available information about the toxic effects of Vitamin A in the diet, how much of it people consume as supplements or in their food and whether these intakes may be harmful to unborn babies. They have now given me their advice and as a result I must caution women who are, or who may become, pregnant against taking any dietary supplements—including tablets and fish-liver oil drops—containing vitamin A, except on the advice of a doctor or ante-natal clinic. The vitamin supplements currently prescribed as part of ante-natal care for pregnant and nursing mothers contain a safe amount of vitamin A and should continue to be taken. I am also advising women who are pregnant, or who could become pregnant that as a matter of prudence they should not eat liver or products made from it such as liver pâte and liver sausage. Other women, men and children are not affected by this advice. Vitamin A is an essential nutrient but it is not essential to eat liver to acquire it. A balanced diet provides sufficient for healthy living. Apart from liver the main sources of vitamin A in the diet are carrots, margarine, dairy products, eggs, all green vegetables, tomatoes and other fruit. Eating such a diet poses no risks from any harmful effects of vitamin A, and women should continue to eat these foods as part of a balanced diet. Women who stop eating liver would however need to maintain, and preferably increase, their iron intakes by consuming more lean red meat and meat products, fortified breakfast cereals, bread and vegetables. The cause of high vitamin A levels in animal liver is being investigated as a matter of urgency with a view to seeing whether changes in current animal feeding practices and in the use of veterinary vitamin A supplements could reduce those levels. These investigations will take some time and, as high levels of Vitamin A have been reported in liver from a number of countries which export it to the United Kingdom, any effective action would have to be in concert with other countries. It is not yet clear how far levels of vitamin A in liver could be reduced but the situation will be closely monitored and fresh advice issued if the position changes.

The CMO's statement, together with further information, has been placed in the Library.