7 Warning Signs of Vitamin B12 Deficiency You Shouldn’t Ignore Your body simply can’t function properly without enough Vitamin B12—it plays a vital role in nerve health, red blood cell formation, and energy production. A deficiency can creep up slowly, but the signs are often clear if you know what to look for. Common symptoms include dizziness, forgetfulness, fatigue, muscle weakness, pale or yellowish skin, a tingling or electric shock sensation in the body, and even blurred vision. If any of