Vitamin B1

Conclusion: PN is associated with lowered plasma vitamin B12 and elevated methylmalonic acid and homocysteine. Overall, interventional studies have suggested that B-vitamins could improve symptoms of PN. Available trials have limitations and generally did not investigate vitamin status prior to treatment. Well-designed studies, especially in non-diabetes PN, are needed. This meta-analysis is registered at PROSPERO (ID: CRD42020144917).

Conclusion: IV thiamine can alleviate neurological symptoms, cognitive dysfunction, and brain imaging lesions associated with WE. We found key limitations in the evidence for IV thiamine and diagnostic standards for WE. Future targeted research should establish clear diagnostic and treatment guidelines for WE to prevent this serious condition from being underdiagnosed or undertreated.

Conclusion: There is no high quality evidence to support the effectiveness of any dietary supplement for dysmenorrhoea, and evidence of safety is lacking. However for several supplements there was some low quality evidence of effectiveness and more research is justified.

Conclusion: There is some evidence to support the use of nutritional interventions for improving psychological symptoms of PMS. However, more research using consistent protocols, procedures to minimize risk of bias, intention-to-treat analysis, and clearer reporting is required to provide conclusive nutritional recommendations for improving PMS-related psychological outcomes.