Vitamin B12 Injection IV or IM Choosing the Right Needle and Syringe for B12 Injections: A Complete Guide Vitamin B D B12 Injections Near Ne Wilmington Urgent Care Clinic Wilmington Urgent Care And Family Clinic Types of injections explained! Understanding the angles: intramuscular (im) : injects deep into the muscle at 90. subcutaneous (sc) : goes under the skin at 45. intravenous (iv) : Is intramuscular (IM) administration of vitamin B12 injections preferred over subcutaneous (SC) administration? Types of injections explained Intramuscular (IM) Inserted at 90 to deliver medication deep into the muscle, allowing relatively fast absorption due to rich blood supply. Subcutaneous (SC) Inserted at about 45