Would be interesting to know how people diagnosed feel because of them, what they are, how treated, causes, symptoms, etc. B-12 and D are two examples of sub-topics for this category that would be helpful. Lots of doctors don't seem to test for these during regular physical exams/blood tests. I think they should. Vitamin D has even been in the news lately as important in helping prevent some cancers, like colon cancer and how more and more people who are trying to avoid skin cancer are now becoming D deficient.