Folic acid before pregnancy: how much and when
400 to 800 mcg, three months ahead.

The best-studied supplement of preconception

Folic acid prevents neural tube defects such as spina bifida and anencephaly. The neural tube, which will become the brain and spinal cord, is already being formed in week 5 of pregnancy and keeps forming through the first 12 weeks. That's why the book calls folic acid the absolute priority of preconception and the most important nutrient for preventing these malformations.

The protection, up to 70% less risk, depends on timing: it applies when folic acid is started at least 3 months before conception and maintained through the first trimester.

Start early, and don't stop at the positive

1. Ideally 3 months before trying. This is the timing behind the up to 70% protection, and the book's 90-day plan starts folic acid in month 1.
2. At least 1 month before. If you're about to stop birth control, you can try in the first cycle, but folic acid should have been taken for at least 1 month, ideally 3.
3. At the positive, keep going. Continue folic acid, or increase it to 800 to 1,000 mcg, as part of the first 24 hours after the positive.
4. Through week 12. The neural tube is forming in the first 12 weeks, so the dose stays through the end of the first trimester.

In other words, folic acid is not something to add once you're pregnant. The up to 70% protection depends on starting before conception, which is why the book makes it the first supplement of Station I.

This is one chapter. The map has 42.

Folic acid opens Chapter 08 of Map to the Positive, on smart supplementation, in Station I, Foundation. The map treats it as step one, not the whole plan: the same station covers the 11 preconception tests, vitamin D and iodine, and the supplements that only make sense in specific situations, and Station V picks folic acid back up in the first weeks after the positive.