nfgo3 the source of the post is irrelevant. It is the information itself that is importnat. As the Rambam says “ushma haemes mimi sheomro.”
All medical associations are in agreement that folic acid decreases the risk of spina bifida. The generally recommended dose is 0.4 mg for average woman. Women who are at increased risk (older, have had affected child) should take 4.0 mg.
It is important for women of child bearing age to take this if their is a chance of them getting pregnant since the benefits are within the first 28 days (this is when the neural tube closes). For many women, beginning taking the supplements once they find out is too late.