Yes, Vitamin B12 can be given through an IV
and patients with pernicious anemia who have optic neuropathy COBALAMIN (Vitamin B12) Deficiency Causes Vegetarians (dietary deficiency) Older adults: atrophic gastritis affects 10% 30% and leads to decrease in hydrochloric acid secretion in the stomach and decreased absorption of Vitamin B12 The liver can store up to six years worth of Vitamin B12 so deficiencies are rare Effects of deficiency Megaloblastic anaemia (pernicious anaemia) Progressive demyelination of nerve cells Elevation in levels of circulating homocysteine that leads to production of defective collagen and elastin with a negative impact on arteries, bone and skin Deep vein thrombosis is associated with homocysteinemia that causes the activation of the intrinsic coagulation cascade Symptoms include fatigue, weakness, constipation, loss of appetite and weight loss Numbness, tingling of the feet imbalance, depression, confusion, dementia, poor memory and glossitis

People taking certain medications may need monitoring for B12 deficiency
It is not a drug, dietary supplement, or cosmetic and must not be represented or used as such
10.1002/ncp.10596 5 BenskyM
While B12 is readily available in animal-derived foods like shellfish, eggs, dairy products, and meats, some individuals may have difficulties absorbing it through their digestive systems