Thiamine has been assigned to pregnancy category A (injectable) and category C (at doses above RDA) by the FDA. Animal studies have failed to reveal evidence of fetal harm. Thiamine is only recommended for use during pregnancy when benefit outweighs risk.

The recommended daily allowance (RDA) for thiamine during pregnancy is 1.4 mg/day regardless of a woman's age. Women carrying more than one fetus may have increased needs for thiamine.

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There are no data on the excretion of thiamine into human milk. The manufacturer recommends that caution be used when administering thiamine to nursing women.

The recommended daily allowance (RDA) for thiamine during lactation is 1.4 mg/day regardless of a woman's age. Women who are breast-feeding more than one infant may have increased needs for thiamine.

See references