I believe it's 1 mg per day. At least that is what I take and that is what was recommended for me by my OB. Try not to worry too much about birth defects. Most are caused by a chromosonal abnormality and a high percentage of the time your body will miscarry early in the pregnancy if that is the case. I have been on this forum a fairly long time now and have only come across 1 or 2 women whose babies were born with a birth defect. There are many of us in our late 30's to mid 40's who are carrying or have delivered healthy babies. I will be 41 when my son is born and have had all the tests, including amnio. He is perfectly healthy. Good luck to you.
you do need to check with your ob, my peri had me on high folic and vit d. folic usually comes in 400mics if im not mistaken and some docs go as high as 2000 a day. good luck!!