The potential hazards of high doses of vitamin B6 in treating nausea and vomiting in pregnancy: A systematic review

Vitamin B6 is frequently utilized as a therapeutic agent for nausea and vomiting of pregnancy (NVP). Research indicates that excessive intake of vitamin B6 can have implications on neurological function, underscoring the importance of cautious consideration when administering vitamin B6 treatment during early pregnancy. This systematic review investigates the effects of high doses of vitamin B6 on pregnant women experiencing NVP. We searched the PubMed (R) MEDLINE (R) database for articles using the following terms: "pregnancy" or "nausea and vomiting during pregnancy" and "vitamin B6." Women with nausea and vomiting symptoms during pregnancy use more than the tolerable amount of vitamin B6. A total of 136 articles were identified from the PubMed (R) MEDLINE (R) database. The etiology and treatment of NVP are briefly outlined, followed by a summary and analysis of 19 relevant literature sources. Among these sources, 12 reports detailed the adverse effects of excessive vitamin B6 intake in women; 164/1226 individuals experienced neurological symptoms such as burning, tingling, paresthesia, ataxia, or perioral numbness. Additionally, out of 245 women, four experienced miscarriages and one had an intrauterine demise. The overconsumption of vitamin B6 has the potential to impact nerve function, particularly during the critical first trimester of embryonic development. It might result in adverse outcomes such as miscarriage, intrauterine fetal demise, and congenital abnormalities.