Vitamin A and Birth Defects

An article in a recent issue of the New England Journal of Medicine warned of the possible relationship between consuming vitamin A at levels at or above 10,000 IU (200 percent of the Daily Value, or DV) or 3000 Retinol equivalents (REs) and some types of birth defects. A relationship between vitamin A intakes and birth defects has been known for some time, but the level of vitamin A that was associated with earlier studies was much higher than the levels indicated by the new study.

As a precautionary measure, the FDA has issued several recommendations to women of child-bearing age about consuming foods containing pre-formed vitamin A, including dietary supplements.

Pre-formed vitamin A is found in animal products, primarily liver, and may be added to fortified foods such as breakfast cereals and dietary supplements. (Examples of pre-formed vitamin A include retinyl palmitate and retinyl acetate, which can be found in these products' ingredient listings.) Women should not exceed the recommended DV for pre-formed vitamin A from these sources.

On the other hand, beta-carotene is a substance found naturally in plants, and it can be converted to vitamin A in the body. It is considerably less toxic than the pre-formed vitamin A. Therefore, women of child-bearing age are advised to choose fortified foods that contain vitamin A in the form of beta-carotene rather than pre-formed vitamin A, whenever possible. The vitamin A in fruits and vegetables is naturally in the form of beta-carotene, and high intakes of vitamin A from these sources is generally not of concern.

Vitamin A is an essential nutrient and, as with all nutrients, the good health of women throughout child-bearing years, including during pregnancy, depends on consuming the appropriate amounts of this nutrient. Taking too little vitamin A can result in adverse effects just as can taking in too much. The key is in finding the "right amount" by carefully reading product nutrition labeling.