Depression Support Group
Depression is a real and debilitating condition that is often misunderstood by family and friends. Its meaning can range from a prolonged period of sadness to an actual mental illness with specific symptoms. Find and share experiences with others who are going through the same struggles.
Not enough information. I never heard of 'seretin'. Low B12 could be caused by serious conditions (or not).
http://www.webmd.com/food-recipes/guide/vitamin-b12-deficiency-symptoms-causes
Was your bloodwork done at a doctors office? The doctor or assistant should have called and explained what these mean.
If not, then you definitely just get a professional opinion on these and see what, if anything needs to be done to correct.