The epidemiology of rickets in the 17th-19th centuries: Some contributions from documentary sources and their value to palaeopathologists.

This article considers the nature of written sources on the epidemiology of rickets in the post-Mediaeval period, and examines the value of these sources for palaeopathologists. There is a progression from 17th-18th century sources, which generally make ex cathedra, qualitative statements on rickets frequency to, in the 19th century, semi-quantitative geographical surveys of its occurrence, through to reports of percentage prevalence in various groups. Of course, even these latter cannot be directly compared with prevalences calculated from excavated skeletal remains, but there are also considerable difficulties in comparing them with one another, and this effectively precludes synthesis to provide reliable information on geographic and temporal trends at anything more than a very broad-brush level. Their problematic nature mandates a cautious approach when using written sources to shed light on the epidemiology of rickets. For palaeopathologists, a useful way of incorporating these sources into a biocultural approach may be to use them in order to formulate hypotheses that can then be evaluated using skeletal evidence.