This study aimed to find an association between ingested amounts of copper and thiamine (vitamin B1) with the severity of stuttering in people who stutter (PWS). For this report, 8 of 19 adults from 18-50 years old filled out an online survey site for 9 weeks. The survey consisted of self-assessed fluency and mood/anxiety scales, as well as food journals. After 4 weeks, the subjects consumed copper and thiamine supplements for 2 weeks each with a 1 week washout period. Formal speech assessments were done pre/post baseline and at the end of each supplement intake. Participants were not informed about the nature of the supplements and the investigator was blinded to the order of the supplements.
