Randomized, double-masked trial
The Vitamin Intervention for Stroke Prevention (VISP) Study, sponsored by the National Institute for Neurological Disease and Stroke (NINDS), is an international multi-center, randomized controlled clinical trial designed to determine if the addition of folic acid, pyridoxine, and cyanocobalamin to best medical/surgical management and risk factor modification reduces secondary cerebral infarction and first ever myocardial infarction over a two year follow-up period. Participants are patients with non-disabling cerebral infarction and with plasma homocysteine levels above the 25th percentile. The putative mechanism for risk reduction is through the effect of the vitamins on lowering homocysteine levels. The CSCC began developmental work for the 5-year VISP Study in September 1996 and randomization began in August 1997.