Vitamin A during pregnancy.

Vitamin A is an essential micronutrient throughout life. In areas of developing countries where vitamin A deficiency is endemic, an estimated 40% of the children are likely to be sub clinically deficient of the vitamin. Yet, the traditional view that preschool age children represent the main population at risk of vitamin A deficiency has been replaced by the growing awareness that sub clinical and even clinical vitamin A deficiency also occurs in women of reproductive age and infants less than 6 month of age. During the period of early foetal development the supply of vitamin A must be carefully managed to ensure that the developing foetus is exposed to neither too little not too much vitamin A because either condition can have teratogenic consequences. Towards the end of gestation, adequate maternal vitamin A status and dietary intakes are important to maximize the vitamin A transferred to the foetus in preparation for parturition and lactation. A review of the current knowledge and prospects for future research is presented.