Vitamin B12 deficiency can cause symptoms like headaches, fatigue, depressive mood, gastrointestinal issues, and more. While vegetarians are at a higher risk of vitamin B12 deficiency, it can affect non vegetarians too. Check Experiencing any of these symptoms? B12 supplementation might be right for you. Some causes of low B12 are diet, alcohol use, certain diseases like Chrohn's and Celiac Disease, and Gastric Bypass surgery, B12 Shots Do You Need a Prescription? A Complete Guide Carter's Walk In + Urgent Care Too Much B12 Symptoms: Overdose Signs & Safe Dosage Bolt Pharmacy Vitamin B12 Benefits and Best Sources Why Do I Feel Worse After My B12 Injection: 6 Body Reactions