B12 injections are also used to treat people with malabsorption (gastrointestinal conditions that prevent proper absorption of B12 from the gut), for example, people with atrophic gastritis (stomach inflammation) and intrinsic factor deficiency (pernicious anemia) or those who have undergone surgical procedures such as gastrectomy or small bowel resection (stomach or intestine removed), autoimmune diseases, etc
NAD is typically prescribed as a subcutaneous injection (into the superficial fat on the abdomen) administered once daily, typically in the evening**
These options have different evidence bases, mechanisms, and adverse-effect profiles from KLOW
When to seek medical care Adults should seek medical care if they have unexplained fatigue, weakness, shortness of breath, dizziness, numbness or tingling in the hands or feet, balance problems, memory changes, or a sore tongue