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 It might not be your lifestyle it could be a B12 deficiency. B12 is essential for energy, mood, and overall wellness and when levels are low, your body feels it. Our Feeling more tired, sluggish or low in mood? You're not alone shorter days and colder weather can leave your body needing that little bit of extra support. Vitamin B12 injections are Low B12 levels can lead to fatigue, numbness, irritability, and moreyet many people don't realize they're deficient. The good news? Testing and treatment are simple with options like injections or dissolvable tablets.