Today we discuss: vitamin D for pain and headache (https://www.ncbi.nlm.nih.gov/pubmed/25261164); chronic diarrhea guidelines (https://www.ncbi.nlm.nih.gov/pubmed/29653941); lorcaserin and T2DM (https://www.ncbi.nlm.nih.gov/pubmed/30293771); and the results of "screening" MRI (https://www.bmj.com/content/363/bmj.k4577).