role of folic acid on symptoms of chronic arsenic toxicity

background: chronic arsenic toxicity (arsenicosis) due to drinking of arsenic contaminated ground water is a global problem. however, its treatment is unsatisfactory. methylation of arsenic facilitates its urinary excretion. persons with relatively lower proportion of urinary dimethyl arsenic acid (dma) are found to have at greater risk of developing symptoms of arsenicosis including its complications. the biochemical pathway responsible for methylation of arsenic is a folate-dependent pathway. studies in rodents and humans suggest that folate nutritional status influences the metabolism of arsenic.the present study compares the effect of giving folic acid on 32 arsenicosis patients during a 6-month period and comparing the results with clinical effect of taking only arsenic-free safe water on 45 age and sex-matched arsenic-affected people for the same period.there was significant improvement of arsenical skin lesion score of both patients treated with folic acid (2.96 ± 1.46 to 1.90 ± 0.90, p< 0.001) and arsenic free safe water(2.91 ± 1.26 to 1.62 ± 1.05, p< 0.001) for a period of 6 months. significant improvement in systemic disease score was also observed from the baseline systemic score in folic acid treated group (4.78 ± 3.43 to 1.00 ± 1.56, p< 0.001) and the group treated with arsenic-free water (1.87 ± 2.11 to 0.82 ± 1.62, p< 0.001).however, there was a significant increased improvement of systematic disease score in the folic acid treated group compared to the control group taking arsenic free water (p< 0.001). this study provides evidence that folic acid treatment in arsenicosis cases could help in reducing clinical symptoms of arsenicosis.