Tread carefully

This mum (or mom, since she's American) has had some good success conquering morning sickness with a range of vitamins. You really feel for women like her that need to vomit all day. That's pretty hellish. People will say, oh that passes after the first trimester, but for some it lasts the whole pregnancy.
That said, I do think you need a doctor to help decide which vitamins to take. I'm a bit paranoid when it comes to taking things while pregnant (or breastfeeding) and think we should be careful. When I was pregnant with LB, I took part in a study to see if a range of vitamins would help ward off pre-eclampsia. I didn't get it (had low blood pressure instead!) but I don't know if I was taking the vitamins or the placebo -- will need to wait until the study is finished (they need 2000 women, from memory) before they will tell the participants. Anyway, I spoke to heaps of people about whether it was ok to take these vitamins before doing it. I'm glad I did though. I felt good about doing my little bit!