Title: Vitamin B12 Deficiency In The Elderly.
Key words: Cobalamine, malabsorption, folic acid, ageing, pernicious anaemia
Date: Oct 1998
Category: 11. Life Changes
Type: Article
Author: Dr Van Rhijn
Vitamin B12 Deficiency In The Elderly.
Introduction
Cobalamine (Vit B12) deficiency in the elderly population is more common than originally thought. It is estimated that up to 15% have insufficient serum concentrations. It is an essential co-enzyme in all DNA-synthesizing cells and in the conversion of excessive vasculotoxic homocysteine.
Aetiology of deficiency
Vit B12 deficiency may be due to a multitude of reasons, which therefore require differentiation:
Intrinsic factor deficiency: Pernicious anaemia; Gastrectomy; Congenital; Atrophic gastritis; Zollinger-Ellison syndrome
Terminal ileal disease: Crohn's disease; IBD; Surgical resection Pancreatic failure: Reduces pH and calcium required for absorption Competition for vitamin B12: Blind loop syndromes; Fish tape worm; raised Vit C
Drugs: Biguanides; Antibiotics; Aspirin
Infection: Tropical sprue; H. pylori
Consequences of deficiency
|
Affected area or organ |
Condition |
Effects of Condition |
|
Blood |
Megaloblastic/Pernicious anaemia |
Anaemia; Jaundice; ê Folate Neutropenia Infection Thrombocytopenia Bleeding |
|
Skin |
Angular cheilosis Glossitis Pigmentation; Alopecia |
Sore mouth; Ulcers ‘Beefy’ red tongue |
|
CVS |
Hyperhomocysteinemia |
Atherosclerosis & CVD |
|
GI tract |
Epithelial abnormalities Stomach + small bowel |
Anorexia; Weight loss Altered bowel habit; Malabsorption |
|
GUS |
Epithelial abnormalities |
Atrophy |
|
CNS |
Mental abnormalities Subacute combined degeneration of the cord |
Dementia; Peripheral neuropathy Paraesthesia; Numbness Difficulty in walking; Ataxia Sclerosis; Demyelination(?) Weakness |
|
Eyes |
Retrobulbar neuritis Optic atrophy |
Poor vision Blindness |
Conclusion
Considering the severe and potentially fatal consequences of a negative B12 balance, it is essential to remain vigilant about this vitamin. It is advisable to measure the serum carrier protein holotranscobalamin II, which provides an earlier indicator of deficiency compared to total serum Vit B12. This should always be assessed in conjunction with the folate status, as B12 deficiency results in secondary folic acid deficiency.