Randomized controlled trial of homocysteine-lowering vitamin treatment in elderly patients with vascular disease.

Randomized controlled trial in elderly patients with ischemic vascular disease from two clinical centers. The active intervention groups each had 23 participants and were assigned to oral vitamin regimens for 12 weeks, with outcomes including homocysteine, cognition, and endothelial and hemostatic markers.

This randomized trial tested oral homocysteine-lowering vitamin regimens for 12 weeks: folic acid 2.5 mg plus vitamin B-12 400 µg daily, riboflavin 25 mg daily, vitamin B-6 25 mg daily, and their combinations. The active regimens were factorially combined with placebo components where applicable and compared across multiple vitamin arms.

Folic acid plus vitamin B-12 markedly lowered plasma homocysteine, with the greatest effect in participants with lower baseline folate or B-12 status. However, this biochemical improvement did not translate into statistically significant gains in cognitive function or in circulating endothelial or hemostatic markers. Riboflavin and vitamin B-6 did not significantly affect homocysteine or cognition. Overall, the trial found no evidence that lowering homocysteine with these vitamins improves short- to medium-term clinical outcomes in this population.

Each active arm had only 23 participants, limiting power to detect cognitive or vascular event differences. The intervention period was short relative to chronic vascular and cognitive outcomes, and the many treatment arms make the comparisons more vulnerable to imprecision and chance findings. Generalizability is limited to elderly patients with ischemic vascular disease from two centers.