We already know how to find the best prenatal vitamins, but we may also need to learn what the benefit the prenatal vitamins can help us before we take it. Researcher had some evidences that supporting the prenatal vitamins brought about the healthy benefit for the pregnant women.
So here, we can collect some useful information as listed below:
Due to concerns about inadequate iodine intake among pregnant and lactating women, in May 2014, the American Academy of Pediatrics issued a statement advising such women to take an iodine-containing supplement. Unfortunately most prenatal supplements currently do not contain the amount of iodine being recommended (150 mcg of elemental iodine from 197 mcg of potassium iodide). (Don’t worry about this, the prenatal vitamins we recommended here are with adequate iodine dosage)
Too much iodine intake during pregnancy can cause problems in infants, but so can too little. Three cases were reported of infants born with congenital hypothyroidism apparently due to their mothers having taken the high potency iodine supplement Iodoral (Optimox, Corp) which contains 12.5 mg of iodine/iodide per tablet more than 11 times the UL and nearly 57 times the RDA for iodine for pregnant women. Congenital hypothyroidism has also been reported in infants born to mothers taking an herbal supplement high in iodine-containing kelp.
For vitamin A
Do not take too much vitamin A. The most important risk involves pregnant women. Vitamin A given in modestly excessive doses can cause birth defects. Much higher doses of vitamin A can potentially damage the liver, central nervous system, bone and skin. The UL for daily intake should not exceed 2,000 IU for children 1 to 3 years old, 3,000 IU for those 4 to 8, 5,666 IU for those 9 to 13, 9,333 IU for those 14 to 18, and 10,000 IU for adults. To minimize the risk of birth defects such as cleft palate, heart defects, and hydrocephalus, the March of Dimes recommends that a pregnant women should not use a multivitamin or prenatal supplement that contains more than 5,000 IU of preformed vitamin A. It also advises that a pregnant woman should not take any vitamin A supplements beyond that amount and minimize consumption of liver, which contains preformed vitamin A. However, these ULs apply only vitamin A consumed from supplements, fortified foods, and animal sources, and does not include vitamin A as beta-carotene or intake from fruits and vegetables.
Folate is known to reduce the risk of certain birth defects. Supplements are generally recommended for women who are pregnant or may soon become pregnant.
In addition, folic acid supplementation at 1,000 mcg per day has been associated with a more than doubling of the risk of prostate cancer.
RDAs of folate for pregnant women, you may refer to here.