Experiencing a Metallic Taste After Getting an Injection Vitamin B12 is essential for healthy oral tissues. Its deficiency can affect the mouth early.., Oral effects , red,smooth,painful tongue(glossitis), recurrent mouth ulcers , burning mouth Metallic taste in your mouth: common causes Aspen Dental 5 Reasons You Get a Metallic Taste in Your Mouth (And How to Avoid It) Why do I have the taste of metal in my mouth? Doctor explains 6 potential causes