autism 3Homocysteine is an amino acid that may indicate inflammation. High levels may indicate inflammation. Generally it accumulates because of a need for either folic acid, vitamin B6 or vitamin B12. Those nutrients are necessary for to body to convert homocysteine to cysteine, and when they are in short supply, there is an accumulation of homocysteine.

Homocysteine levels may be higher in autistic children than in children without autism. A study that was published in Acta Biochem Pol (2011; 58(1): 31-4) compared homocysteine levels in 34 autistic children and in 21 children without the disease. Children with autism had higher homocysteine levels in their urine when compared to children without autism (2.36 vs 0.76). This may be an indication that autistic children are deficient in folic acid and in vitamins B6 and B12.