Vitamin B₆ supplementation in pregnant women with nausea and vomiting

Objective: To determine whether supplementation with vitamin B₆ improves nausea and/or vomiting in pregnancy. Methods: This experimental study was conducted with 60 pregnant women experiencing nausea and/or vomiting prior to the 12th gestational week. Of these women, 30 were treated daily with 10 mg and the remaining 30 with 1.28 mg of pyridoxine hydrochloride for 2 weeks. The primary outcome was the Pregnancy-Unique Quantification of Emesis and Nausea (PUQE) score in each group at the end of treatment. Results: The women experiencing nausea and/or vomiting in pregnancy had significantly lower levels of circulating vitamin B₆ (P = 0.007) compared with those without this symptom. Vitamin B₆ supplementation significantly increased plasma vitamin B₆ concentration (P < 0.05 in both groups). There were no significant differences in PUQE score or in plasma concentration levels of protein, dopamine, serotonin, unconjugated estriol, and ghrelin after supplementation between the 2 groups at baseline, but there was a significantly lesser decrease in PUQE score and a greater increase in vitamin B₆ level and vitamin B₆ concentration to plasma protein concentration ratios in group 1 than in group 2 after supplementation (P < 0.05 for all). Conclusion: Although the high-supplementation group had a greater decrease in PUQE score in comparison to the low-supplementation group, the difference is unlikely to affect the severity of symptoms.