This drug should be used during pregnancy only if the benefit outweighs the risk.

AU TGA pregnancy category: Exempt
US FDA pregnancy category: C

Animal reproduction studies have not been conducted with this drug. There are no controlled data in human pregnancy. It is not known whether this drug can cause fetal harm or adversely affect reproductive capacity in humans.

AU Exempt: Medications exempted from pregnancy classification are not absolutely safe for use in pregnancy in all circumstances. Some exempted medicines, for example the complementary medicine, St John's Wort, may interact with other medicines and induce unexpected adverse effects in the mother and/or fetus.

US FDA pregnancy category C: Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks.

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In one study of lactating women who were taking 2 to 60 mg of niacin per day, the average milk concentration ranged from 1.17 to 2.75 mcg/mL, and was directly proportional to dietary intake. The recommended daily allowance (RDA) for niacinamide during lactation is 18 to 20 mg. Dietary supplementation is only necessary in cases of poor nutritional intake.

A decision should be made to discontinue breastfeeding or discontinue the drug, taking into account the importance of the drug to the mother.

Excreted into human milk: Yes

Comments:
-Lipid altering doses of this drug have the potential for serious adverse reactions in nursing infants.

See references