Effects of homocysteine-lowering with folic acid plus vitamin B12 vs placebo on mortality and major morbidity in...

Area of Science:

• Cardiovascular Medicine
• Nutritional Science
• Clinical Trials

Background:

• Elevated blood homocysteine levels are linked to cardiovascular disease (CVD), but a causal relationship remains unproven.
• Investigating the potential benefits of homocysteine reduction for vascular health is crucial.

Purpose of the Study:

• To determine if reducing homocysteine levels using folic acid and vitamin B12 impacts vascular and non-vascular outcomes.
• To assess the efficacy and safety of homocysteine-lowering therapy in post-myocardial infarction patients.

Main Methods:

• A large-scale, double-blind, randomized controlled trial involving 12,064 myocardial infarction survivors.
• Participants received daily folic acid (2 mg) plus vitamin B12 (1 mg) or a placebo.
• Primary endpoint was the first major vascular event, including coronary events, stroke, and revascularization.

Main Results:

• Supplementation significantly reduced homocysteine levels by 28% (3.8 micromol/L).
• No significant difference in major vascular events (25.5% vs. 24.8%) was observed between the vitamin and placebo groups.
• No significant effects were found on major coronary events, stroke, non-coronary revascularization, vascular deaths, or cancer incidence.

Conclusions:

• Long-term reduction of homocysteine levels via folic acid and vitamin B12 supplementation does not improve vascular outcomes in patients with a history of myocardial infarction.
• This supplementation strategy did not demonstrate adverse effects on cancer incidence.