Maternal Vitamin B12 Levels During Pregnancy and Their Effects on Maternal Neurocognitive Symptoms: A Systematic Review

Background: Vitamin B12 deficiency has been linked to neurocognitive symptoms. Vitamin B12 deficiency in pregnancy may be associated with antenatal or postpartum depression along with other neurocognitive symptoms including restless leg syndrome. Objectives: To systematically review the literature regarding vitamin B12 deficiency and insufficiency in pregnancy and effects on the maternal neurocognitive state. Search Strategy: Medline, Embase, and SCOPUS were searched from inception to October, 2020. Selection Criteria: Reports on vitamin B12 deficiency in pregnancy were searched. Data Collection and Analysis: Data were synthesized and presented narratively. Main Results: The five studies included in the analysis did not demonstrate a statistically significant link between vitamin B12 deficiency or insufficiency and either restless leg syndrome or depression in pregnancy. Conclusions: To date, evidence is lacking that would support a causal link between suboptimal vitamin B12 serum levels and maternal restless leg syndrome or depression.