If you are planning to get pregnant, one 0.4mg folic acid tablet a day is enough during pregnancy preparation. If you have the conditions, you can go to a regular tertiary care hospital to test the activity of tetrahydrofolate reductase, if the activity is particularly good, one 0.4mg of folic acid a day is enough. If the activity is moderate, you should take 0.8mg of folic acid a day, two 0.4mg tablets or one imported Elavil. If the activity is particularly poor, you have to take 1.2mg, you can take three 0.4mg tablets, or you can take one tablet of Maternal. However, if you take Maternal, you cannot take it if you have abnormal thyroid function, so you should do thyroid function test before taking 1.2mg of Maternal.