Clinical aspects of cobalamin deficiency in elderly patients. Epidemiology, causes, clinical manifestations, and treatment with special focus on oral cobalamin therapy

Pseudomicroangiopathic Thrombotic Syndrome: Unveiling the Vitamin B12 Deficiency Connection

Pernicious anemia, a manifestation of vitamin B12 deficiency, can present with a spectrum of hematological abnormalities, sometimes mimicking more severe conditions such as thrombotic microangiopathy (TMA). This case report details a 53-year-old female who presented with significant weight loss, watery diarrhea, and jaundice. Laboratory investigations revealed pancytopenia, hemolysis, and schistocytes, initially suggesting a diagnosis of microangiopathic hemolytic anemia (MAHA). However, significantly low vitamin B12 levels and subsequent bone marrow examination confirmed pernicious anemia with megaloblastic changes. This case underscores the importance of considering vitamin B12 deficiency in the differential diagnosis of patients presenting with TMA-like symptoms. Early recognition and treatment with vitamin B12 supplementation led to rapid clinical improvement and the resolution of symptoms. This report highlights the need for heightened clinical awareness of atypical presentations of pernicious anemia to prevent misdiagnosis and ensure timely, effective treatment.

Altered vitamin B12 metabolism in the central nervous system is associated with the modification of ribosomal gene expression: new insights from comparative RNA dataset analysis

Recent studies have confirmed the direct role of vitamin B12 (VitB12) in the central nervous system (CNS) homeostasis; nevertheless, the detailed mechanisms are poorly understood. By analyzing RNA-Seq and microarray datasets obtained from databanks, this study aims to identify possible basic mechanisms, related to the brain, involved in altering the gene expression under VitB12 deficiency mimicking conditions. The database inquiry returned datasets generated from distinctly heterogeneous experimental sets and considering the quality and relevance requirements, two datasets from mouse and one from rat models were selected. The analyses of individual datasets highlighted a change in ribosomal gene expression in VitB12 deficiency mimicking conditions within each system. Specifically, a divergent regulation was observed depending on the animal model: mice showed a down regulation of the ribosomal gene expression, while rats an upregulation. Interestingly, E2f1 was significantly upregulated under VitB12 deficiency mimicking conditions in the animal models, with a greater upregulation in rats. The rat model also revealed putative E2F1 Transcription Factor Binding Sites (TFBSs) in the promoter of the differently regulated genes involved in ribosomal gene expression. This suggested the possibility that E2F1, being greater expressed in rats, could activate the ribosomal genes having E2F1 TFBSs, thus giving a plausible explication to the divergent regulation observed in animal models. Despite the great diversity of the experimental sets used to generate the datasets considered, a common alteration of the ribosomes exists, thereby indicating a possible basic and conserved response to VitB12 deficiency. Moreover, these findings could provide new insights on E2F1 and its association with CNS homeostasis and VitB12 deficiency.

Influence of metformin intake on serum vitamin B12 levels in patients with type 2 diabetes mellitus

OBJECTIVE

To describe the prevalence of vitamin B12 deficiency among Jordanian patients with type 2 diabetes mellitus treated with metformin and to compare the findings with those who did not receive metformin.

DESIGN AND METHOD

Total 155 patients with type 2 diabetes mellitus, aged between 48 and 82 years were enrolled in the current study. They were divided into two groups; the first (n = 120) was treated with metformin while the second (n = 35) was not. Patients' demographics (age, gender, duration of type 2 diabetes mellitus, smoking status), medication parameters (daily dosage and duration of metformin therapy), and biochemical parameters (hemoglobin level, mean corpuscular volume (MCV), serum vitamin B12, and folate level) were recorded. Definite deficiency was defined as serum vitamin B12 levels of < 150 pg/ml, whereas < 200 pg/ml indicated possible deficiency.

RESULTS

The mean serum ± standard deviation (SD) vitamin B12 level was significantly lower in patients who were treated with metformin (268.5 ± 35.8 vs. 389.5 ± 29.8 pg/ml, p = 0.029). The metformin group had significantly higher prevalence of definite deficiency (32% vs. 9%, p < 0.02) and possible deficiency (48% vs. 30%, p < 0.02). Within the metformin group, the mean serum ± SD vitamin B12 level was significantly lower in those on high dosage (175.2 ± 30.5 vs. 315.6 ± 37.8 pg/ml, p < 0.001). MCV (μm3) levels ± SD were higher in the metformin group (87.5 ± 2.9 vs. 83.7 ± 2.4) with no statistical significance.

CONCLUSION

There is a significant association between metformin intake and vitamin B12 deficiency. Serum vitamin B12 levels should be checked by physicians and serial monitoring is necessary in patients who are treated with metformin.

Oral versus intramuscular administration of vitamin B12 for vitamin B12 deficiency in primary care: a pragmatic, randomised, non-inferiority clinical trial (OB12)

OBJECTIVES

To compare the effectiveness of oral versus intramuscular (IM) vitamin B₁₂ (VB12) in patients aged ≥65 years with VB12 deficiency.

DESIGN

Pragmatic, randomised, non-inferiority, multicentre trial in 22 primary healthcare centres in Madrid (Spain).

PARTICIPANTS

283 patients ≥65 years with VB12 deficiency were randomly assigned to oral (n=140) or IM (n=143) treatment arm.

INTERVENTIONS

The IM arm received 1 mg VB12 on alternate days in weeks 1-2, 1 mg/week in weeks 3-8 and 1 mg/month in weeks 9-52. The oral arm received 1 mg/day in weeks 1-8 and 1 mg/week in weeks 9-52.

MAIN OUTCOMES

Serum VB12 concentration normalisation (≥211 pg/mL) at 8, 26 and 52 weeks. Non-inferiority would be declared if the difference between arms is 10% or less. Secondary outcomes included symptoms, adverse events, adherence to treatment, quality of life, patient preferences and satisfaction.

RESULTS

The follow-up period (52 weeks) was completed by 229 patients (80.9%). At week 8, the percentage of patients in each arm who achieved normal B₁₂ levels was well above 90%; the differences in this percentage between the oral and IM arm were -0.7% (133 out of 135 vs 129 out of 130; 95% CI: -3.2 to 1.8; p>0.999) by per-protocol (PPT) analysis and 4.8% (133 out of 140 vs 129 out of 143; 95% CI: -1.3 to 10.9; p=0.124) by intention-to-treat (ITT) analysis. At week 52, the percentage of patients who achieved normal B₁₂ levels was 73.6% in the oral arm and 80.4% in the IM arm; these differences were -6.3% (103 out of 112 vs 115 out of 117; 95% CI: -11.9 to -0.1; p=0.025) and -6.8% (103 out of 140 vs 115 out of 143; 95% CI: -16.6 to 2.9; p=0.171), respectively. Factors affecting the success rate at week 52 were age, OR=0.95 (95% CI: 0.91 to 0.99) and having reached VB12 levels ≥281 pg/mL at week 8, OR=8.1 (95% CI: 2.4 to 27.3). Under a Bayesian framework, non-inferiority probabilities (Δ>-10%) at week 52 were 0.036 (PPT) and 0.060 (ITT). Quality of life and adverse effects were comparable across groups. 83.4% of patients preferred the oral route.

CONCLUSIONS

Oral administration was no less effective than IM administration at 8 weeks. Although differences were found between administration routes at week 52, the probability that the differences were below the non-inferiority threshold was very low.

TRIAL REGISTRATION NUMBERS

NCT01476007; EUDRACT (2010-024129-20).

Effect of age, sex and body weight on the serum concentrations of cobalamin and folate in cats consuming a consistent diet

Objectives Multiple feline diseases involving the gastrointestinal tract, pancreas, liver and biliary tract are known to cause abnormal serum cobalamin and folate concentrations. Measuring the serum concentration of these vitamins can therefore be a helpful diagnostic tool. However, factors other than disease, in particular age, have also been suggested to have an effect on the serum concentration of cobalamin and folate. In previous studies, the dietary intake was not standardised, or even known, despite diet being the prinicpal source of both vitamins. Therefore, we evaluated the effect of age, sex and body weight on the serum concentration of folate and cobalamin in cats fed the same diet. Methods The serum cobalamin and folate concentrations were measured in 65 apparently healthy cats in a nutrition colony that had been fed an identical diet. A linear model was used to test the relationship between the serum concentration of cobalamin and folate with the variables age, sex and body weight. Results There was a large variation in the serum concentration of both folate and cobalamin, despite identical intake. Serum cobalamin was inversely associated with age ( P = 0.002), and males had higher concentrations than females ( P = 0.039). Serum folate was positively associated with age ( P = 0.01). Conclusions and relevance Independent of diet, serum cobalamin concentration decreases with age. Changes in gastrointestinal function, microflora or metabolism may be responsible. Older cats may be more susceptible to cobalamin deficiency secondary to inappetence or gastrointestinal disease.

A Black Cohosh Extract Causes Hematologic and Biochemical Changes Consistent with a Functional Cobalamin Deficiency in Female B6C3F1/N Mice

Black cohosh rhizome, available as a dietary supplement, is most commonly marketed as a remedy for dysmenorrhea and menopausal symptoms. A previous subchronic toxicity study of black cohosh dried ethanolic extract (BCE) in female mice revealed a dose-dependent ineffective erythropoiesis with a macrocytosis consistent with the condition known as megaloblastic anemia. The purpose of this study was to investigate potential mechanisms by which BCE induces these particular hematological changes. B6C3F1/N female mice (32/group) were exposed by gavage to vehicle or 1,000 mg/kg BCE for 92 days. Blood samples were analyzed for hematology, renal and hepatic clinical chemistry, serum folate and cobalamin, red blood cell (RBC) folate, and plasma homocysteine and methylmalonic acid (MMA). Folate levels were measured in liver and kidney. Hematological changes included decreased RBC count; increased mean corpuscular volume; and decreased reticulocyte, white blood cell, neutrophil, and lymphocyte counts. Blood smear evaluation revealed increased Howell-Jolly bodies and occasional basophilic stippling in treated animals. Plasma homocysteine and MMA concentrations were increased in treated animals. Under the conditions of our study, BCE administration caused hematological and clinical chemistry changes consistent with a functional cobalamin, and possibly folate, deficiency. Further studies are needed to elucidate the mechanism by which BCE causes increases in homocysteine and MMA.

The role of metformin on vitamin B12 deficiency: a meta-analysis review

Metformin is the only biguanide oral hypoglycemic drug, that is used to treat patients with type-2 diabetes mellitus. There are some reports of metformin being associated with decreased serum levels of vitamin B12 (VB12). The objective of this study is to systematically analyze the impact of metformin on the frequency of VB12 deficiency and serum levels of VB12. A search of various databases provided 18 retrospective cohort studies and 11 randomized controlled trials. Pooled estimates of odds ratio with 95% confidence interval using random effect model were conducted. Studies were examined for heterogeneity, publication bias and sensitivity analysis. Separate analysis of randomized control trials (RCTs) including both low-risk and high-risk bias was also conducted. 29 studies were selected with a total of 8,089 patients. 19 studies were rated intermediate or high quality. Primary outcome suggested increased incidence of VB12 deficiency in metformin group (OR = 2.45, 95% CI 1.74-3.44, P < 0.0001.) Heterogeneity was relatively high (I(2) = 53%), with minor publication bias. Secondary outcome suggested lower serum VB12 concentrations in metformin group (Mean difference = -65.8, 95% CI -78.1 to -53.6 pmol/L, P < 0.00001) with high heterogeneity (I(2) = 98%,) and low publication bias. RCTs analysis of low-and high-risk group revealed similar trends. We conclude that metformin treatment is significantly associated with an increase in incidence of VB12 deficiency and reduced serum VB12 levels.

[Vitamin B12 deficiency in the elderly]

The prevalence of vitamin B12 deficiency increases with age. Patients with dementia and spouses of patients with dementia are at special risk for the development of vitamin B12 deficiency. In a normal diet this vitamin is present only in animal source foods; therefore, vegans frequently develop vitamin B12 deficiency if not using supplements or foods fortified with cobalamin. Apart from dementia, most of these manifestations are completely reversible under correct therapy; therefore it is crucial to identify and to treat even atypical presentations of vitamin B12 deficiency as early as possible. This article deals with the physiology and pathophysiology of vitamin B12 metabolism. A practice-oriented algorithm which also considers health economic aspects for a rational laboratory diagnosis of vitamin B12 deficiency is presented. In cases with severe neurological symptoms, therapy should be parenteral, especially initially. For parenteral treatment, hydroxocobalamin is the drug of choice.

Should vitamin B12 tablets be included in more Canadian drug formularies? An economic model of the cost-saving potential from increased utilisation of oral versus intramuscular vitamin B12 maintenance therapy for Alberta seniors

OBJECTIVE

The aim of this study was to estimate the cost-savings attainable if all patients aged ≥65 years in Alberta, Canada, currently on intramuscular therapy were switched to oral therapy, from the perspective of a provincial ministry of health.

SETTING

Primary care setting in Alberta, Canada.

PARTICIPANTS

Seniors of age 65 years and older currently receiving intramuscular vitamin B12 therapy.

INTERVENTION

Oral vitamin B12 therapy at 1000 μg/day versus intramuscular therapy at 1000 μg/month.

PRIMARY AND SECONDARY OUTCOME MEASURES

Cost saving from oral therapy over intramuscular therapy, from the perspective of the Alberta Ministry of Health, including drug costs, dispensing fees, injection administration fees, additional laboratory monitoring and physician visit fees.

RESULTS

Over 5 years, if all Albertans aged 65 years and older who currently receive intramuscular B12 are switched to oral therapy, our model found that $C13 975 883 can be saved. Even if no additional physician visits are billed for among patients receiving intramuscular therapy, $C8 444 346 could be saved from reduced administration costs alone.

CONCLUSIONS

Oral B12 therapy has been shown to be an effective therapeutic option for patients with vitamin B12 deficiency, yet only three provinces and the Non-Insured Health Benefits program include oral tablets on their formulary rather than the parenteral preparation. To ensure judicious use of limited health resources, clinicians and formulary committees are encouraged to adopt oral B12 therapy as a clinically and cost-effective first-line therapy for vitamin B12 deficiency.

Increased risk of cognitive impairment in patients with diabetes is associated with metformin

OBJECTIVE

To investigate the associations of metformin, serum vitamin B12, calcium supplements, and cognitive impairment in patients with diabetes.

RESEARCH DESIGN AND METHODS

Participants were recruited from the Primary Research in Memory (PRIME) clinics study, the Australian Imaging, Biomarkers and Lifestyle (AIBL) study of aging, and the Barwon region of southeastern Australia. Patients with Alzheimer disease (AD) (n=480) or mild cognitive impairment (n=187) and those who were cognitively intact (n=687) were included; patients with stroke or with neurodegenerative diseases other than AD were excluded. Subgroup analyses were performed for participants who had either type 2 diabetes (n=104) or impaired glucose tolerance (n=22).

RESULTS

Participants with diabetes (n=126) had worse cognitive performance than participants who did not have diabetes (n=1,228; adjusted odds ratio 1.51 [95% CI 1.03-2.21]). Among participants with diabetes, worse cognitive performance was associated with metformin use (2.23 [1.05-4.75]). After adjusting for age, sex, level of education, history of depression, serum vitamin B12, and metformin use, participants with diabetes who were taking calcium supplements had better cognitive performance (0.41 [0.19-0.92]).

CONCLUSIONS

Metformin use was associated with impaired cognitive performance. Vitamin B12 and calcium supplements may alleviate metformin-induced vitamin B12 deficiency and were associated with better cognitive outcomes. Prospective trials are warranted to assess the beneficial effects of vitamin B12 and calcium use on cognition in older people with diabetes who are taking metformin.

Hair trace elementary profiles in aging rodents and primates: links to altered cell homeodynamics and disease

Aging is associated with an increased incidence of pathological conditions such as neurodegeneration, cardiovascular and renal disease, and cancer. These conditions are believed to be linked to a disruption in cell homeodynamics, which is regulated by essential trace elements. In this study we used hair elementary analysis by inductively coupled plasma mass spectrometry (ICPMS) to examine age-related profiles of 47 elements in both rats and common marmoset monkeys. Hair was collected from young adult (6 months) and aged (18 months) Long-Evans male rats, and young adult (2 years), middle-aged (4 years) and aged (>8 years) marmosets. The results revealed that aging reduces content levels of cobalt, potassium and selenium while content levels of aluminium, arsenic, boron, mercury, molybdenum, and titanium were elevated in aged rats. Similarly, aged marmosets showed reduced levels of cobalt and elevated levels of aluminium. Case studies in aged rats revealed that myocardial infarction was associated with elevated levels of sodium, potassium and cadmium and reduced zinc, while renal failure was linked to elevated content of potassium, chloride and boron and reduced contents of manganese. Carcinoma was linked to elevated arsenic and reduced selenium levels. These findings indicate that hair elementary profiles in healthy aging and age-related diseases reflect altered cell and organ metabolic functions. Cobalt and aluminium in particular may serve as biomarkers of aging in animal models. Thus, elementary deposition in hair may have predictive and diagnostic value in age-related pathological conditions, including cardiovascular and kidney disease and cancer.

Autoimmune atrophic gastritis--pathogenesis, pathology and management

Autoimmune gastritis is a chronic progressive inflammatory condition that results in the replacement of the parietal cell mass by atrophic and metaplastic mucosa. A complex interaction of autoantibodies against the parietal cell proton pump and sensitized T cells progressively destroy the parietal cells, inducing hypochlorhydria and then achlorhydria, while autoantibodies against the intrinsic factor impair the absorption of vitamin B₁₂. The resulting cobalamin deficiency manifests with megaloblastic anaemia and neurological and systemic signs and symptoms collectively known as pernicious anaemia. Previously believed to be predominantly a disease of elderly women of Northern European ancestry, autoimmune gastritis has now been recognized in all populations and ethnic groups, but because of the complexity of the diagnosis no reliable prevalence data are available. For similar reasons, as well as the frequent and often unknown overlap with Helicobacter pylori infection, the risk of gastric cancer has not been adequately assessed in these patients. This Review summarizes the epidemiology, pathogenesis and pathological aspects of autoimmune metaplastic atrophic gastritis. We also provide practical advice for the diagnosis and management of patients with this disease.

The pathophysiology of elevated vitamin B12 in clinical practice

Hypercobalaminemia (high serum vitamin B12 levels) is a frequent and underestimated anomaly. Clinically, it can be paradoxically accompanied by signs of deficiency, reflecting a functional deficiency linked to qualitative abnormalities, which are related to defects in tissue uptake and action of vitamin B12. The aetiological profile of high serum cobalamin predominantly encompasses severe disease entities for which early diagnosis is critical for prognosis. These entities are essentially comprised of solid neoplasms, haematological malignancies and liver and kidney diseases. This review reflects the potential importance of the vitamin B12 assay as an early diagnostic marker of these diseases. A codified approach is needed to determine the potential indications of a search for high serum cobalamin and the practical clinical strategy to adopt upon discovery of elevated cobalamin levels. While low serum cobalamin levels do not necessarily imply deficiency, an abnormally high serum cobalamin level forms a warning sign requiring exclusion of a number of serious underlying pathologies. Functional cobalamin deficiency can thus occur at any serum level.

The effects of vitamins C and B12 on human nasal ciliary beat frequency

Background

This study was designed to investigate the effects of the vitamins C and B12 on the regulation of human nasal ciliary beat frequency (CBF).

Methods

Human nasal mucosa was removed endoscopically and nasal ciliated cell culture was established. Changes of CBF in response to different concentrations of vitamin C or vitamin B12 were quantified by using high-speed (240 frames per second) digital microscopy combined with a beat-by-beat CBF analysis.

Results

At the concentrations of 0.01% and 0.10%, vitamin C induced an initial increase, followed by a gradual decrease of CBF to the baseline level, while 1.00% vitamin C induced a reversible decrease of CBF. Vitamin B12, at the concentrations of 0.01% and 0.10%, did not influence CBF during the 20-min observation period, while a 1.00% vitamin B12 treatment caused a time-dependent but reversible decrease of CBF.

Conclusions

Treatment with vitamin C or vitamin B12 caused a concentration-dependent but reversible decrease of CBF in cultured human nasal epithelial cells. Therefore, it is necessary to choose a concentration that is safe, effective, and non-ciliotoxic when applying these drugs topically in the nasal cavity.

[Hypervitaminemia B12 (high level of cobalamin): physiopathology, role and interest in clinical practice]

Hypervitaminemia B12 or high serum level of cobalamin B12 is a frequent and clinical underestimated abnormality. Clinically, it can be sometimes paradoxically accompanied by signs of deficiency reflecting a functional deficit in relation to qualitative abnormalities related to defects in tissue uptake and action of vitamin B12. Etiological profile of hypervitaminemias B12 has mostly serious disease entities and for which early diagnosis is crucial to the plan rather than prognostic. These entities are represented mainly by solid malignancies, hematological malignancies and liver diseases. This reflects the potential significance that may have the dosage of vitamin B12 as an early marker of diagnosis of these diseases. Codified approach is needed to determine the potential indications of the search for a hypervitaminemia B12 and practice what to do to pass before the discovery of a high serum level of cobalamin.

Functional implications of vitamin B(12) deficiency

Vitamin B(12) deficiency is a common but underrecognized problem in older adults. Historically, B(12) deficiency was diagnosed once a severe pernicious anemia developed. Scientific developments have led to a new understanding of a broader spectrum of B(12) deficiency and identification of a milder form of deficiency associated with food/vitamin B(12) malabsorption. Using an individual example, this article describes the functional impact of vitamin B(12) deficiency and highlights modern approaches to diagnosis and treatment.

A short review of malabsorption and anemia

Anemia is a frequent finding in most diseases which cause malabsorption. The most frequent etiology is the combination of iron and vitamin B12 deficiency. Celiac disease is frequently diagnosed in patients referred for evaluation of iron deficiency anemia (IDA), being reported in 1.8%-14.6% of patients. Therefore, duodenal biopsies should be taken during endoscopy if no obvious cause of iron deficiency (ID) can be found. Cobalamin deficiency occurs frequently among elderly patients, but it is often unrecognized because the clinical manifestations are subtle; it is caused primarily by food-cobalamin malabsorption and pernicious anemia. The classic treatment of cobalamin deficiency has been parenteral administration of the vitamin. Recent data suggest that alternative routes of cobalamin administration (oral and nasal) may be useful in some cases. Anemia is a frequent complication of gastrectomy, and has been often described after bariatric surgery. It has been shown that banding procedures which maintain digestive continuity with the antrum and duodenum are associated with low rates of ID. Helicobacter pylori (H pylori) infection may be considered as a risk factor for IDA, mainly in groups with high demands for iron, such as some children and adolescents. Further controlled trials are needed before making solid recommendations about H pylori eradication in these cases.

Anaemia in the elderly

Anaemia is highly prevalent in elderly populations, particularly in long term care facilities and geriatric wards. Even mild anaemia is associated with adverse health outcomes. Although senescence is considered to be a contributing factor, underlying pathology always has to be thoroughly explored. The most frequent etiologies of anaemia in the elderly are anaemia of chronic disease/inflammation; iron, folate and cobalamin deficiency; and myelodysplastic syndrome. Multiple concomitant etiologies are frequently present. The diagnostic workup is straightforward, not very invasive and should be done systematically. Nutrient deficiencies require complete workup and cure. Anaemia of chronic disease/inflammation ideally is taken care of by treating the underlying disease. If this is not possible and if glomerular filtration rate is significantly decreased, treatment with erythropoietin should be considered. Most cases of myelodysplastic syndrome will benefit from supportive care, but a specific subgroup responds particularly well to oral thalidomide analogues. Transfusions should be avoided.

Reversible dementias

The causes of potentially reversible dementia syndromes are legion, as many perturbations of body chemistry can lead to dysfunction of higher cortical function, including the chemical interventions we call medication. It is vital for the cautious clinician to take a painstaking history to develop a differential diagnosis of potential causally related reversible phenomena. This, coupled with an extensive examination and a widecast net of serological, and when appropriate, cerebrospinal, electrophysiologic, and neuroimaging studies can increase the potential for discovering these mimics of the primary neurodegenerative dementias. While some cases of reversible dementia will be obvious from history and physical and only require a few confirmatory tests or even just a trial of treatment (or often, discontinuation of a suspect treatment), it is worthwhile to perform more extensive work-up in cases of dementia, as the costs to allowing our patients to remain in an incapacitated, possibly progressive, state of disability far outweigh the costs of ruling out reversible causes. This chapter provides a lengthy, though by no means exhaustive, review of etiologies and work-up for the currently recognized reversible dementias.

Update of nutrient-deficiency anemia in elderly patients

Anemia, defined as a hemoglobin level < 13 g/dL in men and < 12 g/dL in women, is an important healthcare concern among the elderly. Nutrient-deficiency anemia represents one third of all anemias in elderly patients. About two thirds of nutrient-deficiency anemia is associated with iron deficiency and most of those cases are the result of chronic blood loss from gastrointestinal lesions. The remaining cases of nutrient-deficiency anemia are usually associated with vitamin B12, most frequently related to food-cobalamin malabsorption, and/or folate deficiency and are easily treated (nutrient-deficiency replacement).

Severe vitamin B12 deficiency resulting in pancytopenia, splenomegaly and leukoerythroblastosis

Deficiency of vitamin B12 is a well known cause of megaloblastic anemia and pancytopenia. Splenomegaly and leukoerythroblastosis are much less well known manifestations of B12 deficiency. We report a B12 deficient female with severe pancytopenia including normocytic anemia who also had enlarged spleen and circulating nucleated red blood cells as well as circulating immature myeloid cells. Although these findings are reported in the earlier literature, more modern reviews of the subject often fail to mention this association. We review the literature on these unusual manifestations of B12 deficiency and remind clinicians that splenomegaly and erythroblastosis can serve as diagnostic clues in cases of severe megaloblastic anemia secondary to B12 deficiency.