Vitamin B12 status of elderly persons from urban low-income households

[Preventive nutritional services for the elderly]

Population aging is a global. These demographic transitions have brought about dramatic changes in the world's health needs and status. Chronic diseases of aging account for nearly half of population morbidity and mortality in the developing regions of the world 85% of deaths and disability in developed regions. Chronic diseases in the elderly is, in over 60%, associated with malnutrition. Malnutrition is one of the few preventable risk factors for chronic diseases. Carefully planned population-based nutrition interventions can lower risk malnutrition and thus for chronic diseases and as well as for their adverse outcomes. Nutrition interventions can also be used to reach particularly vulnerable segments of the population, such as extremely frail elders, to reduce the prevalence of nutrient deficiencies. Clearly, the prevention of nutrition-related problems in the population, including older persons, has important global health implications.

Cobalamin and folate deficiency in the elderly

Elderly persons are more likely to have low values for serum and erythrocyte folate, and for serum cobalamin. Many of those with low vitamin levels have biochemical abnormalities consistent with true deficiency, including increased formiminoglutamic acid excretion, abnormal marrow deoxyuridine suppression, and raised serum levels of methylmalonic acid and homocysteine. Therapy with the appropriate vitamin reverses the biochemical defect. Despite this, the clinical consequences for most elderly persons are remarkably few. True megaloblastic anaemia is rare, and the small number of therapeutic trials to date have not improved the levels of haemoglobin in the treated subjects, although the mean corpuscular volume has decreased significantly. There has been recent concern that these low blood vitamin levels might be important causes of nervous system damage, but studies specifically of the elderly have not demonstrated overall improvements in neurological function following therapy. Vascular damage from high blood homocysteine levels secondary to cobalamin or folate deficiency remains a potential hazard. Dietary insufficiency, malabsorption of protein-bound vitamin B12 secondary to atrophic gastritis, and defective absorption of folyl polyglutamates seem the likeliest possible causes. Pernicious anaemia, although a common cause of severe megaloblastic anaemia in the elderly, is an infrequent cause for the low cobalamin levels in population studies. Although the benefits are uncertain, the balance of the evidence suggests that one should treat elderly persons with low values of cobalamin or folate. Crystalline vitamin B12 and folic acid are absorbed normally and are therefore suitable for replacement therapy, provided that pernicious anaemia is excluded.

Cobalamin levels are not reduced in Alzheimer's disease: results from a population-based study

OBJECTIVE

To determine whether there is a relationship between serum cobalamin levels, normal aging, and Alzheimer's Disease (AD).

DESIGN

Cross-sectional survey.

SETTING

A district (Kungsholmen) in Stockholm, Sweden.

PARTICIPANTS

Population-based cohort of 545 subjects aged more than 74 years. The sample was selected on the basis of evidence of cognitive impairment from all inhabitants in an area of Stockholm (2368 individuals), both living at home or in institutions.

MEASUREMENTS

Serum cobalamin levels and diagnostic evaluation for a diagnosis of dementia and type of dementia.

RESULTS

The serum cobalamin levels in non-demented individuals decreased 5.5 pmol/L with an increase of 1 year of age (regression coefficient = -5.53; P < 0.0001). However, the regression coefficient was 0.21 (P = 0.91) in demented people and 2.57 (P = 0.32) in AD subjects. There was no difference between serum cobalamin levels in demented, AD, and non-demented subjects, except for the oldest ages where demented people and AD sufferers showed higher values. AD patients still living in their own homes had significantly lower cobalamin concentrations compared with institutionalized AD sufferers. The prevalence rate of cobalamin deficiency was 15.5% (95% CI = 11.5-19.5) in normal aging and 18.1% (95% CI = 10.3-25.9) in AD.

CONCLUSIONS

These data suggest that serum cobalamin levels decrease in normal aging, but not in dementia or AD. A lower cobalamin concentration observed in AD sufferers still living in their own homes compared with institutionalized persons with AD seemed to be related to but not fully explained by eating habits. Patients with AD living in their own homes are at risk of developing cobalamin deficiency, and monitoring of serum cobalamin concentrations might be useful in this group.

Prevalence of intrinsic factor antibodies and vitamin B12 malabsorption in older patients admitted to a rehabilitation hospital

It is possible that the commonly measured serum level of vitamin B12 may miss some cases when used to detect vitamin B12 malabsorption and deficiency in older persons. Serum levels of vitamin B12 and intrinsic factor antibody (IFAB) were determined on 250 consecutive patients over the age of 70 admitted to a rehabilitation hospital. Patients with abnormal results on either test were given the standard Schilling test when possible. Eight patients had documented B12 malabsorption. Of these, five had a low serum B12 level alone and one had a low serum B12 level and a positive IFAB level; however, two patients had positive IFAB and normal serum B12 levels. Serum IFAB level may serve as a useful adjunct to serum B12 level in detecting vitamin B12 malabsorption in older patients.

Low serum cobalamin levels in a population study of 70- and 75-year-old subjects. Gastrointestinal causes and hematological effects

We examined causes and hematological consequences of low serum cobalamin (vitamin B12) concentration in two representative population samples of 70-year-old (N = 293) and 75-year-old subjects (N = 486). Subjects with values below 130 pmol/liter (4.8% and 5.6%, respectively) were investigated with Schilling test, upper gastrointestinal endoscopy, determination of serum gastrin and group I pepsinogens, and bone marrow examination. Gastrointestinal abnormalities of etiologic significance were found in 26 of the 32 examined subjects: atrophy of the gastric body mucosa (N = 16, with pernicious anemia in six), partial gastrectomy (N = 6), and intestinal malabsorption (N = 4). Megaloblastic hematopoiesis was found in 10 individuals, four of whom had macrocytic anemia. Our results indicate that low serum cobalamin concentration in the elderly is usually a consequence of disease rather than of high age per se and that gastric mucosal atrophy is a major etiologic factor.

Vitamin B12 (cobalamin) and folate blood levels in geriatric reference group as measured by two kits

For serum vitamin B12 levels there was little apparent difference between a geriatric healthy reference group and a hospitalized group for the total population studied; however, the hospitalized males did have an increased prevalence of values less than normal range. The frequency distribution for both sexes of the geriatric reference group gave lower range limits than manufacturer's normal range. (68-632 vs 133-708 pmol/L for Becton Dickinson, and 125-609 vs 179-930 pmol/L for Bio-Rad, using 95% non-parametric limits). For folate there was an increased incidence in values of less than normal in the hospitalized group versus the geriatric reference group, but there was no difference in the ranges calculated for the latter compared to either manufacturer's normal range derived from a younger population. Comparison of results by two manufacturers' kit methods confirmed Bio-Rad's claim to increased low-end sensitivity of standard curve in range of clinical interest.