Vitamin B12 deficiency
| Vitamin B12 deficiency | |
|---|---|
 |
|
| Cyanocobalamin | |
| Classification and external resources | |
| Specialty | Neurology |
| ICD-10 | E53.8 |
| ICD-9-CM | 266.2 |
| DiseasesDB | 13905 |
| MedlinePlus | 000574 |
| Patient UK | Vitamin B12 deficiency |
Vitamin B12 deficiency, also known as hypocobalaminemia, refers to low blood levels of vitamin B12. A wide variety of signs and symptoms may occur including a decreased ability to think and behavioural and emotional changes such as depression, irritability, and psychosis. Abnormal sensations, changes in reflexes, and poor muscle function can also occur as may inflammation of the tongue, decreased taste, low red blood cells, reduced heart function, and decreased fertility. In young children symptoms include poor growth, poor development, and difficulties with movement. Without early treatment some of the changes may be permanent.
Common causes include poor absorption from the stomach or intestines, decreased intake, and increased requirements. Decreased absorption may be due to pernicious anemia, surgical removal of the stomach, chronic inflammation of the pancreas, intestinal parasites, certain medications, and some genetic disorders. Decreased intake may occur in those who eat a vegan diet or are malnourished. Increased requirements occur in HIV/AIDS and in those with rapid red blood cell breakdown. Diagnosis is typically based on vitamin B12 blood levels below 120–180 picomol/L (170–250 pg/mL) in adults. Elevated methylmalonic acid levels (values >0.4 micromol/L) may also indicate a deficiency. A type of low red blood cells known as megaloblastic anemia is often but not always present.
...
Wikipedia