The B Vitamins

Vitamin B-6 is a family of water-soluble compounds that includes pyridoxine, pyridoxamine, and pyridoxal. This family is involved in the manufacture of most protein-related compounds, such as hormones, hemoglobin, neurotransmitters and many enzymes. In addition, it is needed by the body for making amino acids (the building blocks of protein), the formation of prostaglandins, and the conversion of the amino acid tryptophan to the B-vitamin niacin. Pregnant women frequently have low blood levels of vitamin B6, possibly because of the developing infant's increased need for the vitamin. Supplementation is often recommended as a symptomatic treatment for vomiting, nausea, lethargy, fatigue, and depression in affected women.

Research has shown that pyridoxine supplementation may promote a healthy immune system in the developing fetus. It is thought to be involved with the transfer of certain immune factors to the fetus while it is still in the womb and via milk to the breastfed infant. A recent study has shown that the level of immunoglobulins (antibodies) transferred from mother to unborn baby is dependent on the mother having adequate vitamin B6 levels herself. Thus, maternal vitamin B6 status during pregnancy likely affects the protection against infection that the mother transfers to the fetus during pregnancy and to the baby during breast-feeding. These bacteria-fighting factors may be of major importance for the infant's defense against infection, particularly in areas that have a high risk of infection.

The vitamin B6 concentration in human milk is influenced by the mother's vitamin B6 intake and nutritional status. When mothers are supplemented during nursing, the vitamin B6 intakes of breast-fed infants reflect the amount of their mother's supplement. There are also growth advantages for infants when mothers receive pyridoxine supplementation during lactation. This supplementation appears to be very safe. Doses of vitamin B6 over 100 times the U.S. RDA of 2 mg/day have been used in the treatment of certain conditions, without reports of adverse effects. However, in the pregnant women, daily intake should probably not exceed 20 mg in the last trimester; higher doses may shut off breast milk production. In fact, there are few indications for using levels above 5 mg per day. Supplementation should also continue during lactation if commenced during pregnancy. Higher doses are sometimes recommended during the first trimester to help manage nausea and vomiting. The National Academy of Sciences recommends vitamin B-6 supplementation of 2 mg per day for women carrying multiple fetuses, for pregnant adolescents, and for pregnant substance abusers. A women who is considering supplementation should speak with her health care provider. Other B vitamins are also important during pregnancy. For instance, riboflavin deficiency is common during pregnancy although it has yet to be associated with any specific health threat. Niacin and thiamin supplementation during the first trimester of pregnancy may improve infant size and birth weight. These benefits are not apparent when supplementation is only provided during the second and third trimesters. Folic acid, pyridoxine, riboflavin, niacin, and thiamin are commonly found in nutritional supplements designed for pregnant and lactating women. The National Academy of Sciences recommends supplements of 2.0 mcg vitamin B-12 (cobalamin) for complete vegetarians that are pregnant. Complete vegetarian women who are considering pregnancy or who are currently pregnant should discuss supplementation with their health care provider.

Disclaimer: This information is intended as a guide only.   This information is offered to you with the understanding that it not be interpreted as medical or professional advice.  All medical information needs to be carefully reviewed with your health care provider.