The cremation process destroys a lot of information that can usually be obtained from the human skeleton. Diseases are especially difficult to observe. This has caused a paucity in our knowledge of the disease load in populations that practiced cremation as their main funerary ritual. Dr. Barbara Veselka and Prof. Christophe Snoeck, of the Brussels Bioarchaeology Lab and research groups MARI and AMGC for the first time have detected vitamin D deficiency in cremated human remains.
source https://phys.org/news/2021-10-interglobular-dentine-cremated-human-teeth.html