Agreed with first reply!
1st trimester is really just folic acid. I was worried too cos I kept seeing other mummies like already taking prenatal vitamins. Then my doc said the only impt one is folic acid.
Then once you are in 2nd trimester, your doctor would usually advice which one you need to take. most common is multivitamin and fish oil (DHA).
but most important is to sleep well and eat well!