Is vitamin B6 safe during pregnancy?

What does the evidence say about vitamin B6 during pregnancy?

1. 1.9 mg a day is the recommended dietary allowance for vitamin B6 in pregnancy, the same at ages 14 to 18 and 19 to 50, up from 1.3 mg for non-pregnant adult women. 1
2. The tolerable upper intake level in pregnancy is 100 mg a day for ages 19 and up and 80 mg for ages 14 to 18. In practice the limit is about supplements: high intakes of vitamin B6 from food have not been reported to cause adverse effects, while sustained high-dose pyridoxine supplements can cause severe sensory neuropathy. 1
3. In two randomized, placebo-controlled trials, 30 to 75 mg of oral pyridoxine a day significantly decreased nausea in pregnant women, though results across the wider body of prospective studies have been mixed. 1
4. In 2023 the European Food Safety Authority set a much lower upper level of 12 mg a day for all adults, including pregnancy, after reviewing the link between vitamin B6 and peripheral neuropathy. US and European ceilings differ substantially on this nutrient. 1
5. About half of pregnant people experience nausea and vomiting in the first few months and 50 to 80 percent experience nausea alone. It typically resolves after 12 to 20 weeks, though it often lasts all day rather than only the morning. 1

Is vitamin B6 safe in each trimester?

• First trimester. This is when the higher nausea doses come up, since nausea and vomiting usually peak in the first months. The gap between the 1.9 mg nutritional target and a 30 to 75 mg nausea dose is large, which is exactly why it is a provider conversation.
• Second trimester. Nausea typically settles between 12 and 20 weeks. If you started a higher dose earlier, this is the natural point to ask whether you still need it rather than continuing by habit.
• Third trimester. The nutritional target is unchanged at 1.9 mg. Long stretches at high doses are the concern with B6, so an ongoing high dose deserves a check-in rather than an automatic refill.