Why do I need vitamin A during pregnancy?
Vitamin A, a fat-soluble vitamin stored in the liver, is important for your baby's embryonic development; cell growth; eye, heart, limb, and ear development; healthy skin and mucous membranes; infection resistance; bone growth; and fat metabolism. Vitamin A is particularly essential for pregnant women because it helps with postpartum tissue repair, as well as maintaining normal vision and helping fight off infections.
How much vitamin A do I need?
According to the government, you need to get about 770 micrograms RAE of vitamin A each day during pregnancy. (This is approximately equal to 2,565 IU.) While you're nursing, your needs increase to 1,300 mcg RAE (4,330 IU) per day.
Note that the government recently changed the units they use to measure vitamin A from "retinol equivalents" (REs) to a more accurate measurement called "retinol activity equivalents" (which is expressed as mcg RAE). They also continue to express amounts of vitamin A in international units (IU), since those are the units used on vitamin labels. So we'll use both.
Actually, it's easy to get plenty of vitamin A from the average American diet, since it's widely available in meat, dairy, fish, eggs, and fortified cereals in the form of "preformed vitamin A" as well as in most fruits and vegetables in the form of beta-carotene (a nutrient that gets converted to vitamin A by your body as needed).
The trick during pregnancy is not to get too much of the preformed vitamin A, which in high doses can cause birth defects and liver toxicity. The government considers 3,000 mcg RAE (10,000 IU) the maximum amount of preformed vitamin A that you should get from supplements, animal sources, and fortified foods each day. (NOTE: You can still get as much beta-carotene as you want from fruits and vegetables.)
This is one important reason why you shouldn't double up on your prenatal vitamins or take any supplements that your practitioner doesn't recommend. Most prenatal vitamins contain at least part of their vitamin A in the form of beta-carotene, but some over-the-counter brands and other kinds of multi-vitamins contain excessive amounts of preformed vitamin A, so check the labels or show them to your practitioner before taking them.
One more thing: The risk of birth defects from getting too much vitamin A is also the reason that pregnant women and those trying to conceive should stay away from the prescription acne drug isotretinoin (also known by the brand name Accutane, among others) and other drugs related to retinol (a compound of vitamin A), including topical tretinoin (Retin-A), a cream that's used for skin conditions.
