Family Practice, General Practice, and Drug and Alcohol Rehabilitation Physicians, often administer various injectable vitamins such as B-12 and B-Complex as a complementary therapy to medication and/or other treatments. Injectable B-12 is often the preferred route of administration for this vitamin and is the most frequently administered injectable in the Primary Care Physician's office. Many physicians recognize the benefits of Injectable B-12 (Cyanocobalamin) in the treatment of pernicious anemia or megaloblastic anemia, serious conditions found in patients lacking intrinsic factor (a glycoprotein that naturally aids in the absorption of B-12). Cyanocobalamin is also used to treat deficits in B-12 associated with Crohn's disease, HIV, various surgical procedures, medicines, and diet. B-12 has been found essential in supporting a healthy nervous system.