§ Mrs. Renée Shortasked the Secretary of State for Education and Science (1) what studies are in progress to establish whether women should take extra vitamins in early pregnancy to prevent babies developing spina bifida;
(2) what evidence there is that taking extra vitamins in early pregnancy helps to prevent babies developing spina bifida.
§ Mr. William SheltonI understand that it has long been suspected, largely on the basis of animal studies, that maternal nutritional factors—particularly vitamin deficiencies—are associated with fetal malformations. Although there is no firm evidence of such an association in the human, a study published in 1980 suggested that if the diets of women who had already had a neural tube defect pregnancy were supplemented with a multivitamin preparation around the time of conception of a subsequent pregnancy, the risk of a similar outcome would be substantially reduced. Another study published last year suggested that a reduction of risk might be achieved with just one vitamin—folic acid. An investigation is now in progress in Dublin to compare the two therapies.
In the Medical Research Council's view, the results of these earlier studies are encouraging, but they do not conclusively establish the value of vitamin therapy in preventing neural tube defects. The lack of an adequate 354W control group gives rise to doubt about their interpretation, and until a properly controlled trial is undertaken there can be no proof that vitamin therapy is effective. I understand that the Medical Research Council therefore plans to conduct such a trial. Some 20 centres, both in this country and abroad, are likely to participate. The trial will be designed to provide clearer evidence of the effects of multivitamins and to enable a separate assessment to be made of the benefits of folic acid.