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.
Niacin, (Vitamin B6) is a coenzyme for several enzyme systems involved in the metabolism of proteins, carbohydrates, and fats. Long-term use of large doses of vitamin B6 can, however, cause complications in the peripheral nervous system.