Metallic Taste in Mouth: 10 Common Causes (& What to Do) Tua Sade Metallic Taste When Running? It's Capillary Stress! 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 Treatment for metallic taste from chemotherapy Vitamin B12 deficiency symptoms: A metallic taste in your mouth could be a sign Express.co.uk