In November 2018 researchers from Iran published their review of the medical scientific literature to assess the association between folate, vitamin B6 and vitamin B12 intake and risk of coronary heart disease. A total of 11 studies, involving 369,746 individuals and 5,133 diagnoses of corornary heart disease were included in the review. Results showed that the risk of coronary heart disease reduced for each 250 µg/day increment in folate intake and for each 0.5 mg/day increment in vitamin B6 intake. Only a very slight association between vitamin B12 and increase in oesophageal cancer was noted. The results did not change materially when the analyses were restricted only to dietary vitamin intake. A further analysis revealed a dose-response association between folate and vitamin B6 intake and risk of coronary heart disease. In conclusion, a higher intake of folate and vitamin B6 is associated with a lower risk of coronary heart disease. It should, however, be noted that too much vitamin B can be harmful.
Jayedi A, Zargar MS. Intake of vitamin B6, folate, and vitamin B12 and risk of coronary heart disease: a systematic review and dose-response meta-analysis of prospective cohort studies. Crit Rev Food Sci Nutr. 2018 Nov 15:1-11.