The majority of pregnant women do not complain of morning sickness until the 6th week of pregnancy, 2 weeks after a missed period. But for some women, that nagging feeling can start as early as one week after conception, a full week before a missed period. Changes in hormones account for the queasiness that occurs.
DRUG CLASS AND MECHANISM: Niacin (nicotinic acid, vitamin B3) is a part of the normal diet that is essential to various chemical reactions in the body.
What is niacin? Niacin (nicotinic acid) is a B vitamin that's used by your body to turn food into energy. Niacin also helps keep your nervous system, digestive system and skin healthy. That's why niacin is often a part of a daily multivitamin, though most people get enough niacin from the food they eat.