http://www.marchofdimes.com/professionals/14332_1152.asp
Should a pregnant woman eat liver?
There is some concern about consuming liver during pregnancy. Liver is a good source of protein and is rich in certain vitamins and minerals. These include:
* The B vitamin folic acid, which helps prevent certain birth defects
* Iron, which helps prevent anemia
* Vitamin A, which is needed for normal fetal growth and development
However, in the case of vitamin A, liver may contain too much of a good thing.
Some studies suggest that high doses of vitamin A may cause birth defects. According to the Institute of Medicine (IOM), the recommended dietary allowance (RDA) of vitamin A for pregnant women is 2,565 IUs (international units) per day (7). In a 1995 study, women who took more than 10,000 IUs of vitamin A daily (nearly 4 times the amount recommended by the IOM) in the first two months of pregnancy had more than double the risk of having a baby with birth defects (8). Other studies have suggested that doses under 30,000 IUs daily probably do not cause birth defects, but the lowest dose that may cause birth defects is unknown (9).
The body makes its own vitamin A, when needed, from substances such as beta carotene, which is found in yellow and green vegetables. This raw material for the vitamin is completely safe and healthy during pregnancy. However, much of the vitamin A consumed is the preformed vitamin (retinol) which, in excessive amounts, may cause birth defects. Preformed vitamin A is found in many vitamin supplements and some foods, including meats, eggs, dairy products and fortified breakfast cereals.
Liver is the only food that provides very high amounts of vitamin A. For example (7):
* A 3-ounce serving of beef liver may contain 27,000 IUs.
* A 3-ounce serving of chicken liver may contain 12,000 IUs.
A pregnant woman who eats liver regularly may consume enough vitamin A to pose a risk to her baby.
Though it is not proven that eating liver causes birth defects, the safest approach is for pregnant women to minimize their consumption of liver. A pregnant woman also should be sure that her multivitamin or prenatal supplement contains no more than 5,000 IUs of preformed vitamin A. Some prenatal vitamins contain no preformed vitamin A, substituting beta carotene or omitting vitamin A entirely. She should not take any vitamin A supplements beyond that amount (10).