Unfortunately no benefit to cardiovascular mortality or morbidity has been observed in randomized clinical trials, except in patients who had successful coronary angioplasty. A modest decreased rate of coronary restenosis following coronary angioplasty has been noted after lowering of plasma homocysteine levels, but this requires confirmation that is unlikely to be forthcoming.
In a sound crossover study, however, optimization of dietary folate or low-dose folic acid supplements lowered homocysteine levels, but they did not enhance endothelial function in healthy adults, irrespective of the MTHFR C 677T genotype.