- associated with a slight yellowing of the skin or eyes because of increased breakdown of abnormal red blood cells.
Neurological and blood-related symptoms can overlap with many other conditions, so the next group of signs is worth recognizing too—especially changes involving the mouth, digestion, and vision.
3. Oral and Gastrointestinal Symptoms
Vitamin B12 deficiency can also affect the mouth and digestive system.
- Glossitis: The tongue may become inflamed, swollen, smooth, or unusually red.
- Loss of Appetite: Some people may experience a reduced appetite, which can contribute to unintended weight loss.
- Digestive Issues: Digestive symptoms can include diarrhea, constipation, nausea, or other gastrointestinal changes.
4. Ocular Symptoms
In more significant or prolonged deficiency, the optic nerve can be affected.
- Vision Changes: Some people may develop changes in vision or color perception.
- Optic Nerve Damage: Severe or prolonged deficiency can damage the optic nerve and, in uncommon cases, contribute to vision loss.
