Vitamin B12 deficiency. Important new concepts in recognition

Vitamin B12 deficiency: an important reversible co-morbidity in neuropsychiatric manifestations

BACKGROUND

Vitamin B12 deficiency is a common condition causing neurologic, cognitive, psychiatric, and mood symptoms. With varied religious, ethnic, and socioeconomic heterogeneity among the people in India greatly influencing their dietary habits and with the high prevalence of Helicobacter pylori infection, Vitamin B12 deficiency is not uncommon, but is often under recognized due to the lack of classical symptomatic presentation.

MATERIALS AND METHODS

Retrospective study on Vitamin B12 deficiency with neuropsychiatric symptoms in patients who attended neurology, psychiatry, and geriatric OPDs for a period of 1 year in a specialized neuropsychiatric institute in South India.

RESULTS

Out of 259 patients who had Vitamin B12 deficiency (<220 pmol/L), 60 had neuropsychiatric symptoms. Among them the Vitamin B12 levels were <150 (severe), 150-200 (moderate), and 201-220 pmol/L (mild) in 19, 24, 17 patients, respectively. Twenty one were diagnosed with Posterior dementias, 20 with frontotemporal dementia, 7 with Schizophrenia, 4 each with Parkinson's disease and alcohol-dependent syndromes (ADS), 3 with bipolar affective disorder, and 1 with Creutzfeldt-Jakob disease. Eight patients also had hypothyroidism. First symptom of presentation was behavioral disturbances in 30 (50%), memory loss in 20 (33.9%), and sensorimotor and movement disorders in 9 (15.3%), and 56.7% were vegetarians while 43.3% were nonvegetarians. In our study, Vitamin B12 deficiency was more prevalent in elderly males (56.67%) and was associated with increased severity of behavioral disturbances (P = 0.043) which was the most common presentation. Memory loss was present in 16 (84.2%) patients of severe Vitamin B12 deficiency. Hindi mental status examination (HMSE) score was graded as <20, 20-24, 24-31 in 37 (61.7%), 10 (16.7%), and 13 (21.7%) patients, respectively. Cognitive decline in Vitamin B12 deficiency was significantly associated with increased serum cholesterol (P = 0.019) and was significantly prevalent in neurological disorders when compared with primary psychiatric illnesses (P = 0.001). Mean folate and mean homocysteine in our study was 11.7 ± 6.44 ng/ml and 17.77 ± 5.45 μmol/L, respectively. Eighty percent of the population had normal folate levels whereas mean homocysteine values were much higher than that of the western population (10-12 μmol/L).

CONCLUSION

Vitamin B12 deficiency though common in India is often overlooked. It increases the load of cognitive decline and accentuates vascular risk factors in neuropsychiatric illnesses. Vitamin B12 deficiency also increases homocysteine levels contributing to the vascular comorbidity in cerebro and cardiovascular illnesses. So prevention, early detection, and management of this reversible Vitamin B12 deficiency state is of profound importance.

Zinc, vitamin A, and micronutrient supplementation in children with diarrhea: a randomized controlled clinical trial of combination therapy versus monotherapy

OBJECTIVE

To compare the clinical efficacy of supplementation of zinc, zinc plus vitamin A, and zinc plus combination of micronutrients and vitamins (iron, copper, selenium, vitamin B(12), folate, and vitamin A) on acute diarrhea in children.

STUDY DESIGN

This was a double-blind, randomized, placebo-controlled trial. Children aged 6 to 24 months with diarrhea and moderate dehydration were randomized to receive zinc plus placebo vitamin A (group 1), zinc plus other micronutrients plus vitamin A (group 2), zinc plus vitamin A (group 3), or placebo (group 4) as an adjunct to oral rehydration solution. Duration, volume of diarrhea, and consumption of oral rehydration solution were compared as outcome variables within the supplemented groups and with the placebo group.

RESULTS

The 167 study subjects included 41 in group 1, 39 in group 2, 44 in group 3, and 43 in group 4. All 3 supplemented groups demonstrated a significant reduction in outcome variables (P < .0001) compared with the placebo group. Group 3 had the lowest reduction of outcome variables and group 2 had a speedy recovery, but differences among the supplemented groups were not statistically significant.

CONCLUSIONS

Supplementation with a combination of micronutrients and vitamins was not superior to zinc alone, confirming the clinical benefit of zinc in children with diarrhea.

The KCNE2 potassium channel ancillary subunit is essential for gastric acid secretion

Genes in the KCNE family encode single transmembrane domain ancillary subunits that co-assemble with voltage-gated potassium (Kv) channel alpha subunits to alter their function. KCNE2 (also known as MiRP1) is expressed in the heart, is associated with human cardiac arrhythmia, and modulates cardiac Kv alpha subunits hERG and KCNQ1 in vitro. KCNE2 and KCNQ1 are also expressed in parietal cells, leading to speculation they form a native channel complex there. Here, we disrupted the murine kcne2 gene and found that kcne2 (-/-) mice have a severe gastric phenotype with profoundly reduced parietal cell proton secretion, abnormal parietal cell morphology, achlorhydria, hypergastrinemia, and striking gastric glandular hyperplasia arising from an increase in the number of non-acid secretory cells. KCNQ1 exhibited abnormal distribution in gastric glands from kcne2 (-/-) mice, with increased expression in non-acid secretory cells. Parietal cells from kcne2 (+/-) mice exhibited normal architecture but reduced proton secretion, and kcne2 (+/-) mice were hypochlorhydric, indicating a gene-dose effect and a primary defect in gastric acid secretion. These data demonstrate that KCNE2 is essential for gastric acid secretion, the first genetic evidence that a member of the KCNE gene family is required for normal gastrointestinal function.

The platelet count/mean corpuscular hemoglobin ratio distinguishes combined iron and vitamin B12 deficiency from uncomplicated iron deficiency

Combined deficiencies of iron and cobalamin are common. The aims of this study were to investigate the significance of the parameters of the complete blood count (CBC) in differentiating microcytic anemia due to pure iron deficiency anemia (IDA) from anemia due to combined deficiencies of vitamin B(12) and iron (IDA-B12). The study was carried out with 122 patients (100 female) who had microcytic red blood cell indices with IDA-B12 and 105 patients (95 female) with IDA. Group IDA-B12 patients had decreased hemoglobin levels, mean corpuscular volumes, mean corpuscular hemoglobin (MCH) levels, and MCH concentrations but had increased platelet counts (PLT). Using these parameters, we developed a PLT/MCH ratio parameter that has high values when IDA is accompanied by cobalamin deficiency. The cutoff value of >12.00, with a 74.6% sensitivity and a 41.9% specificity, appears to be the most convenient value for screening. We advise measuring the levels of cobalamin in patients with IDA associated with a high PLT/MCH ratio.

Cobalamin

Cobalamin (vitamin B12) is an essential nutrient derived exclusively from bacterial sources. It is an essential cofactor for three known enzymatic reactions. Untreated deficiency, caused by either the autoimmune disease pernicious anemia or nutritional lack, results in a macrocytic anemia and/or subacute combined degeneration of the spinal cord and is eventually fatal. Cobalamin in serum is bound to two proteins, transcobalamin and haptocorrin. The former is responsible for the essential delivery of cobalamin to most tissues. Inadequate tissue availability of cobalamin results in increased concentration of methylmalonic acid and homocyst(e)ine due to inhibition of methylmalonyl-CoA mutase and methionine synthase, respectively. Strict vegetarians have long been known to be at risk of cobalamin deficiency, which develops insidiously over many years. It is now clear that a significant number of the elderly and HIV-positive individuals are also at increased risk of deficiency. Any individual with reduced ability to split cobalamin from food-protein may also become deficient even though intrinsic factor is present. Diagnosis of cobalamin deficiency has frequently relied on total serum cobalamin and the Schilling test. Newer approaches such as analysis of methylmalonic acid, homocyst(e)ine, holotranscobalamin, anti-intrinsic factor antibodies, and serum gastrin may provide more cost-effective testing, as well as identify those with a covert deficiency.