Vitamin B12 is essential for your body. It plays a key role in DNA synthesis, energy production, and maintaining a healthy central nervous system. A deficiency in Vitamin B12 often develops gradually, How Quickly Can I Expect to Feel Better After a B12 Injection? Your body needs vitamin B12 to keep blood cells healthy and to make your nerves work right. But what happens when you run low? Here are some signs: https: wb.md 46StuWK Why Do I Feel Worse After My B12 Injection? Causes & Management Bolt Pharmacy