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.


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


Effects of Condition


Megaloblastic/Pernicious anaemia

Anaemia; Jaundice; ê Folate

Neutropenia Infection

Thrombocytopenia Bleeding


Angular cheilosis


Pigmentation; Alopecia

Sore mouth; Ulcers

‘Beefy’ red tongue



Atherosclerosis & CVD

GI tract

Epithelial abnormalities

Stomach + small bowel

Anorexia; Weight loss

Altered bowel habit; Malabsorption


Epithelial abnormalities



Mental abnormalities

Subacute combined degeneration of the cord

Dementia; Peripheral neuropathy

Paraesthesia; Numbness Difficulty in walking; Ataxia

Sclerosis; Demyelination(?) Weakness


Retrobulbar neuritis

Optic atrophy

Poor vision



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.