Where Can I Get a B12 Injection in Las Vegas, NV? Vitamin B12 Deficiency: Causes, Symptoms, and Treatment If you have a low vitamin B12 level, injections can go a long way toward improving your health and well being. But if your B12 level is normal, don't fall for claims that If you've been feeling run down lately you could be deficient in Vitamin B12. Physical symptoms of B12 deficiency include mouth ulcers, fatigue, digestive issues and muscle aches. There are also neurological