--papers or any other evidence that iron-deficiency anemia causes neuropathy.

But there are numerous blood conditions associated with both iron-deficiency anemia and neuropathy, from vascular autoimmune conditions to blood cancers such as multiple myeloma and Waldenstrom's macroglobumeria. In these cases both the neuropathy and the iron deficiecny are secndary to other mechanisms of the syndrome. So a thorough hematological work-up is a good idea.