If you are experiencing a vitamin B12 deficiency symptoms may include tiredness, weight loss, and constipation
Oral Pills Vitamin B12 plays a vital role in keeping your body healthy
Allergy to vitamin B12: two cases of successful desensitization with cyanocobalamin

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

If low or low-normal, use higher dose supplementation or injectable b12
This is especially helpful for people who have a problem with digestive issues or cannot absorb B12 through food