Morning sickness is nausea that occurs during pregnancy. Morning sickness affects a large proportion of pregnant women. It is most common during the first trimester. Feeling sick is a sign that pregnancy hormones are high enough to sustain a pregnancy. Women who experience morning sickness are less likely to have a miscarriage than those who don't. Hormonal changes of pregnancy are thought to play a role. Rarely, severe or persistent nausea or vomiting may be caused by a medical condition unrelated to pregnancy such as thyroid or liver disease.
A daily multivitamin supplement may help to relieve morning sickness, though there is not a lot of evidence for this. A pregnancy multivitamin should contain folic acid, iron, calcium and iodine. Treatment isn't necessary for most cases of morning sickness. If your morning sickness symptoms persist, however, your pregnancy care provider may prescribe vitamin B-6 supplements, antihistamines and possibly anti-nausea medications. Vitamin B6 supplements can be useful, but doses above 200 mg per day can actually be harmful to treat morning sickness.