B-12 Shots in Post Diagnosis, Recovery & Treatment of Celiac Disease Posted June 5, 2008 · Report to Admin I haven't been here in a while. I recently (Monday to be exact) started B-12 shots and Vitamin D and Folic Acid supplements after my yearly endoscopy, blood work and a bone density test revealed major deficiencies in these areas along with elevated ferritin levels. I have always heard that B-12 shots give you a boost of energy but I seem to have gone in the opposite direction and am more tired than before. Is there anyone out there who can explain this or has had the same reaction? Thanks so much.