Why Do We Need Folic Acid During Pregnancy?

Folic acid, which is also called folate, is a B vitamin. The best food sources of folic acid are fortified cereals. Folic acid is a type of B vitamin that is normally found in foods such as dried beans, peas, lentils, oranges, whole-wheat products, liver, asparagus, beets, broccoli, brussels sprouts, and spinach.
Folic acid plays an important role in the production of red blood cells and helps your baby's neural tube develop into her brain and spinal cord.
Taking a prenatal vitamin with the recommended 400 micrograms (mcg) of folic acid before and during pregnancy can help prevent birth defects of your baby's brain and spinal cord. Take it every day and go ahead and have a bowl of fortified cereal, too.
When they are pregnant they should take 600 mcg a day and 500 mcg a day while breastfeeding. Interestingly, low folate levels in fathers-to-be may also be linked to birth defects. 
About video: This video begins with a description of folic acid and its necessity to the body. The lack of folic acid can cause certain birth defects which are also described in the video. The required dosage for different individuals are finally stated.