Feeling worse after B12 Injection: Answering concerns. La Vie Med Spa Vitamin B12 Allergy: Symptoms and Alternatives TikTok Vitamin B12 deficiency symptoms: A metallic taste in your mouth could be a sign Express.co.uk 7 Reasons Behind Sour or Bitter Taste in Your Mouth If you've been feeling weak, foggy, or experiencing numbness in your hands and feet, it could be a sign of vitamin B12 deficiency. B12 is essential for nerve function and red blood