Individual-level prevention of some of the effects of exposure to PM2.5 through nutrient supplementation (vitamin B complex) was demonstrated in a recent study by the Harvard Clean Air Research Center in the Proceedings of the national Academies of Sciences. In a blind, sham- and placebo-controlled crossover intervention trial, ten healthy volunteers received B6, B9, and B12 vitamin supplementation before controlled exposure to PM2.5. Epigenetic markers on blood cells DNA and mitochondrial DNA content were measured before and after exposures. While exposure to PM2.5 induced epigenetic changes to genes related to energy metabolism and depleted mitochondrial DNA compared to sham exposures, vitamin supplementation drastically reduced these effects. Despite the limitations, the study provides evidence of a potential strategy to limit at least some adverse effects of PM2.5 through individually-controllable action.