Do high doses of vitamins B₆ and B₁₂ and folic acid, which lower total homocysteine levels, reduce the risk of recurrent stroke, myocardial infarction or death compared with low doses in people with non disabling acute ischaemic stroke?

Multicentre randomised controlled trial.

High dose vitamins reduced mean total homocysteine levels by 2 μmol/l more than low dose vitamins. In people surviving a non disabling acute ischaemic stroke, no significant differences in rates of recurrent ischaemic stroke, coronary heart disease or death occurred between people receiving high dose or low dose vitamins over 2 years (see Table 1).

Table 1 Outcomes at 2 years in people with ischemic stroke receiving high versus low doses of vitamins.  Event  Low-dose (AR)(N=1853)  High-dose (AR) (N=1827)  Adjusted hazard ratio† (95% CI)  p value  Death  117 (6.9%)  99 (5.9%)  0.9 (0.6 to 1.1)  0.24  Ischaemic stroke  148 (8.8%)  152 (9.2%)  1.1 (0.8 to 1.3)  0.68  Coronary heart disease  123 (7.4%)  114 (7.0%)  0.9 (0.7 to 1.1)  0.62  Kaplan Meier estimates of events within 2 years.  †Analysis was performed with proportional hazards models adjusting for characteristics that differed significantly between treatment groups at baseline (see method notes).

In people with ischaemic stroke, lowering homocysteine levels does not reduce the rate of recurrent stroke, coronary heart disease or death.