孕期和哺乳期都要吃的 is iodine/Neurokare, and you don't start iodine until actually pregnant.... not folic acid
Folic Acid you take before pregnancy and until 12 week pregnant
You can go to GP or Family Planning clinic to get a prescription for Folic Acid ($5 for three months supply)which is what Elevit has, but a lot cheaper because government pays for it. Elevit is expensive only because of the brand+multivitamin which you don't necessary need.
You take Folic Acid before pregnancy and until 12 week preg.