Signs and Symptoms of Vitamin B12 Deficiency Signs You May Have a B12 Deficiency B12 Shots in Friso, Sherman, Anna. and Sunnyvale, TX 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 Why Do I Feel Worse After My B12 Injection? Understanding Post Injecti Oxford Origins Benefits of Vitamin B12 Shots Complete Health Partners