go back

VITAMIN B12 DEFICIENCY [DD]

VITAMIN B12 DEFICIENCY [DD]
---
OMIM = Online Mendelian Inheritance of Men
---

Detail information to gene locus by the National Center for Biotechnology Information NCBI:
 At present, no ‘gold standard’ test exists for the diagnosis of vitamin B12 defi ciency and as a consequence, the diagnosis requires consideration of both the clinical state of the patient and the results of investigations [Shipton MJ, Thachil J 2015]

Low vitamin B12 intake
- Vegetarianism
- Chronic alcoholism
- Older people
Autoimmune
- Pernicious anaemia
- Sjögren’s syndrome
Food-bound cobalamin malabsorption
- Atrophic gastritis
- Chronic gastritis
- Helicobacter pylori-associated gastritis
- Bacterial overgrowth
Surgery
- Post-gastrectomy
- Ileal resection
Malabsorption
- Small intestinal bacterial overgrowth
- Chronic pancreatic exocrine insufficiency
- Crohn’s disease
- Coeliac disease
- Achlorhydria
Obstetric/gynaecological
- Oral contraceptive
- Hormone replacement therapy
- Pregnancy
Genetic
- Transcobalamin II deficiency
Drugs
- Metformin
- Proton pump inhibitors
- Histamine H2-receptor antagonists
Laboratory findingsHomocysteine inc (plasma)
Methylmalonic acid (plasma)
Vitamin B12 dec (serum)
   Methylmalonic acid inc (urine)
Symptoms   abnormal movement
   anemia
   depression
   gait disturbance
   headache (severe, recurrent or occipital, migraine)
   megaloblastic anemia
   muscle weakness
   myelopathy
   peripheral neuropathy
    neutropenia (decreased neutrophils)
    onset, adolescent
    onset, childhood
    onset, infancy
    onset, neonatal
    pancytopenia
    psychosis
    thrombopenia, thrombocytopenia