Vitamin supplementation reduces the level of homocysteine in the urine of autistic children

Significant differences in homocysteine levels in the urine of autistic children are observed. We hypothesized that vitamin supplementation might reduce the level of urinary homocysteine. To rationalize such a hypothesis, analyses were performed using the gas chromatography/mass spectrometry method. The homocysteine level in the urine of autistic children was measured twice: (1) before vitamin supplementation (group C, 30 autistic children) and (2) after supplementation, with either folic acid and vitamins B6 and B12 (group A1, 24 autistic children) or vitamins B6 and B12 alone (group A2, 6 autistic children). The homocysteine level in the urine of autistic children before vitamin supplementation was 2.41 ± 1.10 mmol/mol creatinine (mean ± SD difference). After treatment, the homocysteine level was reduced to 1.13 ± 0.44 and 1.33 ± 0.39 mmol/mol creatinine for A1 and A2 groups, respectively. The intake of vitamins B6 and B12, together with folic acid, was found to be more effective in lowering the levels of urinary homocysteine than the intake of vitamins B6 and B12 alone. Our findings may lead to the recommendation of including vitamins B6 and B12 together with folic acid supplementation in the diets of children with autism.