Nature Made's folic acid (B9) seems to be the most effective of all the folic acid brands I've tried, and it's one of the cheapest. Aside from it's usefulness for those who are pregnant, anemic, or have other diseases, it's also a great supplement for hair growth! After taking Nature Made folic acid for about a year, I noticed significant hair growth, in both new hair and length!

It doesn't have cellulose so It doesn't put weight like other vitamins.