With a dysregulation of the transsulfuration pathway (homocysteine to L-cysteine) sufficient L-cysteine for iron-sulfur cluster formation is not synthesized. Sulfur for iron-sulfur cluster biogenesis is derived from L-cysteine. Supplemental iron increases levels of iron-sulfur proteins. Supplemental iron can partly compensate for dysregulation of the transsulfuration pathway in schizophrenia. Selenomethionine, the food form of selenium is metabolized by enzymes in the transsulfuration pathway. Metabolism off Se-methylselenocysteine by-passes the transsulfuration pathway whereby Se-methylselenocysteine can provide bioavailable selenium for individuals with schizophrenia. Taurine is synthesized from L-cysteine. With L-cysteine not synthesized appropriately taurine will not be synthesized at appropriate levels. Taurine is needed to form various bile acids, With low levels of taurine there will not be sufficient taurine conjugated bile acids. Fat absorption requires bile acids. With low levels of taurine due to low levels of L-cysteine fat absorption will be impaired. Supplemental taurine and supplemental essential fatty acids will compensate for low levels of taurine due to low levels of L-cysteine which are in turn due to dysregulation of the transsulfuration pathway. Taurine by sparing L-cysteine will also increase levels of L-cysteine.
An Important Warning: No supplements that contain L-cysteine or L-methionine should be supplemented. And no supplements that reduce cystine to L-cysteine, such as lipoic acid, should be supplemented. See the Treatment page for supplements that can be of assistance in the treatment of schizophrenia.