The role of B vitamins in stroke prevention

Abstract

Elevated plasma levels of homocysteine (Hcy) are a recognized risk factor for stroke. This relationship represents one aspect of the debated `Hcy hypothesis’. Elevated Hcy may be an independent and treatable cause of atherosclerosis and thrombotic vascular diseases. Further observations indicate that proper dietary supplementation with B-vitamins decreases total plasma Hcy concentrations and may be an effective intervention for stroke prevention. Metabolic vitamin B₁₂ deficiency is a nutritional determinant of total Hcy and stroke risk. Genetic factors may link B vitamins with stroke severity due to the impact on Hcy metabolism of polymorphism in the genes coding for methylenetetrahydrofolate reductase, methionine-synthase, methionine synthase reductase, and cystathionine β-synthase. Several meta-analyses of large randomized controlled trials exist. However, they are not completely in agreement about B vitamins' role, particularly folic acid levels, vitamin B₁₂, and B₆, in lowering the homocysteine concentrations in people at high stroke risk. A very complex relationship exists between Hcy and B vitamins, and several factors appear to modify the preventive effects of B vitamins in stroke. This review highlights the regulating factors of the active role of B vitamins active in stroke prevention. Also, inputs for further large, well-designed studies, for specific, particularly sensitive subgroups are given.

Keywords:

• B vitamins
• folic acid
• cobalamin
• riboflavin
• pyridoxine
• nutrients
• sources
• stroke
• homocysteine
• hyperhomocysteinemia

Disclosure statement

The authors reported no potential conflict of interest.

Funding

The authors received no financial support for this article.