Vitamin B12 Absorption Research Articles

Étude Transversale sur les Effets Indésirables de la Chlorhydrate de Métformine chez 130 Patients Diabétiques Type 2 Admis au Centre Médical et à la Maison du Diabète de Sidi Bel-Abbès

MetforminHydrochloride is an antidiabetic used for many years, currently; it considered the first choice in treatment of type 2 diabetes (T2D). It decreases insulin resistance, does not induce hypoglycaemia, increases glucose utilization in the liver and skeletal muscle, and decreases hepatic glucose production. Its adverse effects (AE) are gastrointestinal, decrease in vitamin B12 absorption, abnormalities of hemogram and rarely skin reactions. The objective of this study was to report the type and frequency of AEs of Metformin Hydrochloride used in the therapeutic management of T2D patients admitted to the medical center and the diabetes home of Sidi Bel-Abbès in Algeria. A cross-sectional descriptive study was carried out over a period of four months, from January 1st, 2017 to April 30th, 2017, involving 130 patients treated with Metformin Hydrochloride consulting at Mimoun City Diabetes Home and Gambetta Diabetes Center in the town of Sidi Bel-Abbès. The primary outcome measure was the determination of the type and frequency of AEs related to normal dosages or overdose use of Metformin Hydrochloride in T2D. Data were collected from patient records, using a questionnaire, and analyzed using Statistical Package for the Social Sciences, version 20 software. 130 patients were included, including 82 women, with a mean age of 51.08±8.85 years (30-66). One hundred and ninety-eight (198) AEs were reported, an average of 1.52 AEs per patient. Among them, 95 (47.98%) AEs are digestive disorders (30.77% of patients suffered from diarrhea, 10.77% had nausea and vomiting, 8.46% suffered from abdominal pain and bloating, 3.85% lost their taste, 7.69% complained of epigastric cramps and 11.54% of anorexia), 29 (14.65%) AEs are hypoglycaemia, 73 (36.87%) AEs are other symptoms and 1 (0.50%) EI is vitamin B12 deficiency and no cases of lactic acidosis or allergic reaction were reported. Five (3.85%) patients had a total and lasting intolerance to Metformin Hydrochloride leading to its discontinuation following persistent diarrhoea. AEs of Metformin Hydrochloride used in the management of T2D patients consulting at the medical center and the Diabetes home of Sidi Bel-Abbès are frequent. Digestive disorders were the most frequent, diarrhea was very frequent and led to discontinuation of treatment in 3.85% of T2D patients, followed by nausea and vomiting, then abdominal pain, bloating and epigastric cramps, and rarely taste metallic. Hypoglycaemia was frequent following its association with insulin, the onset of headaches and fatigue were frequent, but no case of lactic acidosis or allergic reaction was reported. Due to a lack of means, the dosage of homocysteine and methylmalonic acid had not been carried out to confirm the vitamin B12 deficiency in the patient whose level was less than 200ng/mL. A precise assessment of the imputability of reported AEs is necessary.

The Effects of Proton Pump Inhibitors in Acid Hypersecretion-Induced Vitamin B12 Deficiency: A Systematic Review (2022).

Gastroesophageal reflux disease (GERD) is the most common disease, for which proton pump inhibitors (PPIs) are a widely used class of drugs. Due to their efficacy and relative safety profile, PPIs are used chronically by GERD patients. Although it is a safe drug, particular attention focuses on the long-term adverse effects of PPI. The association with vitamin deficiencies has received additional focus since chronic PPI treatment increases the incidence of vitamin B12 deficiency, especially in the elderly. However, numerous studies regarding the establishment of an association between PPI and vitamin B12 status revealed conflicting results. In this systematic review, we systematically examined observational studies that focused on the impact of chronic PPI effects on vitamin B12 absorption and diagnostic biomarkers of vitamin B12 deficiency. Our review showed significant changes in diagnostic biomarkers of vitamin B12 status in long-term PPI users, including elevated homocysteine and methylmalonic acid (MMA) concentration levels defining cellular vitamin B12 deficiency. Although there is uncertainty regarding the exact mechanism, it supports the concept that long-term intake of PPI can have clinical implications for vitamins.

Vitamin B12 Supplementation Adequacy in Australian Vegan Study Participants.

In our initial analysis of the Australian Vegan Study we estimated the mean daily intake of vitamin B12 of each participant and compared this to the Recommended Dietary Intake (RDI). However, the proportion of vitamin B12 that can be absorbed from large doses typically contained in oral supplements is considerably lower than the amount absorbed from food. In this analysis we took into account the estimated absorption from supplements in order to compare adequacy of vitamin B12 intake to the RDI. A cross-sectional online survey was used to obtain information from women (N = 1530) of reproductive age on a vegan diet in Australia. Vitamin B12 intake from food was estimated using a validated food frequency questionnaire and detailed questioning was used to estimate supplemental intake. We used published data on dose-dependent absorption rates to estimate amount of the vitamin absorbed to enable comparison to the RDI. Supplementation practices varied widely. Based on estimated amount absorbed, 39% of participants had an estimated total intake of vitamin B12 below RDI equivalency, compared to 26% based on mean daily intake. The potential absorption of vitamin B12 needs to be considered when estimating adequacy of intake and recommending supplementation.

PSUN222 Prevalence of Vitamin B12 Monitoring Among Patients Receiving Metformin in a Public Hospital

Abstract Background Metformin reduces intestinal absorption of Vitamin B12 in up to 30% of patients and lowers serum Vitamin B12 concentrations in 5-10%. The dose and duration of metformin use correlates with the risk of Vitamin B12 deficiency. Low serum levels may be detected as early as 3-4 months after starting metformin; however, symptomatic deficiency is more likely to present after 5-10 years of metformin therapy. In 2017, the American Diabetes Association (ADA) updated its treatment guidelines to recommend patients taking metformin undergo regular monitoring of Vitamin B12 levels. To better understand acceptance and application of these guidelines, we undertook an assessment of such monitoring within a single hospital center serving the low-income population in Atlanta, GA to assist in guiding optimal monitoring and patient management. Methods Data was collected from a single hospital center using electronic medical records (EMR) and the SlicerDicer tool to identify all outpatients for whom metformin was prescribed either as a single agent or in combination therapy during January 1 – December 31, 2021 and then measure Vitamin B12 prescribing among two cohorts during the same time period: primary care patients and patients followed by the diabetes center. Results During the period studied, of the total 2,336,914 patients documented in the EMR, 30,803 (0.01%) were outpatients whom metformin had been prescribed either as a single agent or in combination therapy. Of these, 816 patients (2.6%) had Vitamin B12 levels ordered and measured. The prevalence of Vitamin B12 levels ordered and measured was greater among primary care patients (673 of 8,971 [7.5%]) when compared with patients followed by the diabetes center (25 of 1,081 [2.3%]) (chi-square p<0.001). A second analysis determined that Vitamin B12 levels were abnormally low among 172 (23.7%) primary care patients and 25 (28%) patients followed by the diabetes center (chi-square p=0.78). Conclusion Our study determined that among two outpatient cohorts who were prescribed metformin there was suboptimal adherence to the ADA's recommendation for regular monitoring of Vitamin B12 levels. The findings of this study will be used to develop approaches for increasing and optimizing ordering and monitoring Vitamin B12 levels for patient care management. Increased awareness of the relationship between metformin and Vitamin B12 deficiency and standardized approaches to monitoring are needed. Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m.

Comparison of the Efficacy of Oral Methylcobalamin Tablets vs. Nasal Spray (NASO B12) in Diabetic Patients on Metformin Therapy

Context: Metformin is known to increase in the risk of developing vitamin B12 deficiency. This study aimed to compare the effectiveness of nasal spray of methylcobalamin (NASO B12) and methylcobalamin tablets for treating vitamin B12 deficiency in diabetic patients receiving metformin. Materials and Methods: In this parallel-group, comparative, open-label clinical study, patients (n = 100) were assigned to two groups: nasal spray of methylcobalamin (NASO B12) (methylcobalamin 250 µg/spray), sprayed in each nostril every alternate day for a total of seven doses (Group 1: a total of 3500 µg methylcobalamin per patient) and oral methylcobalamin tablets, a single daily dose of 1500 µg for a total of seven doses (Group 2: a total of 10,500 µg methylcobalamin per patient). The assessment of efficacy was carried out by measuring serum vitamin B12 levels at baseline, day 7, and day 14. Statistical Analysis Used: The analysis used is Student’s unpaired t-test. Results: NASO B12 treatment resulted in vitamin B12 levels of ≥400 pg/mL (recently updated normal levels as per American Academy of Family Physicians) in 86% and 92% of patients, on day 7 and day 14, respectively, whereas no patient attained ≥400 pg/mL with oral therapy. NASO B12 therapy resulted in higher mean vitamin B12 levels of 485.88 and 570.16 pg/mL when compared with 172.26 and 185.44 pg/mL with oral tablets on day 7 and day 14, respectively. Conclusion: NASO B12 provided much superior absorption of vitamin B12 when compared with oral vitamin B12 tablets and can be used as an effective alternative.

Development of a Sensitive ELISA for Gastric Intrinsic Factor and Detection of Intrinsic Factor Immunoreactivity in Human Serum.

Gastric Intrinsic Factor (IF) is produced by the parietal cells of the stomach and secreted into the gastrointestinal tract where it ensures the active absorption of vitamin B12. We hypothesized that a small amount of IF ends up in the circulation and can be measured in serum. The aim of this study was to develop an assay for measuring human IF and to demonstrate its presence in serum. We designed a sensitive ELISA for measurement of human IF using a commercial monoclonal antibody and an in-house polyclonal antibody as capture and detecting antibody, respectively. Imprecision, accuracy, and linearity of the assay were examined. We established a reference interval based on serum samples from 240 healthy donors, and explored the daily IF fluctuations in 20 healthy subjects. Employing a prototype IF ELISA and size exclusion chromatography experiments, we demonstrated the presence of IF in human serum. In its final design, the IF ELISA has a measurement range of 0.2 to 50 pmol/L. The intra-assay and total imprecision were 7.9% and 15%, respectively. The 95% reference interval (18–65 years) was 1.7–11.6 pmol/L. No diurnal fluctuation or notable sex differences were observed. Our results suggest that the assay is capable of detecting and quantifying human IF in the circulation and may prove useful in the characterization of patients with impaired IF production.

Nature vs nurture in Food selection; A debate!

When it comes to dietary and nutritional preferences, no discussion of human nutrition is validated without addressing the underlying genetic composition. Genetic differences might also shadow someone’s food likes and dislikes, enrooted to food preferences in nutritional behavior. Among the food bloggers its always been a point of debate that among the ‘Nature versus nurture’ which is more powerful. Recent literature states that scientist are still tracing this ancient concept touching temperament to exercise and from tendencies to eat. Numerous factors play an important role in our food selection and affect what we eat, however current literature have displayed that possibly the DNA plays a bigger role in a person’s diet and food choices than we expect.
 ‘Our DNA affects what we eat’. The genetic code can play a significant role in the alteration of tendencies towards food, involving gluten sensibility, taste choices, and lactose intolerance, among others. Additionally, multiple notable scientists and researchers have associated specific genetic pointers with specific characteristics. Such as recent studies linked a variant of a genes for bitter sense of taste stimuli; responsible for either one enjoy drinking coffee or not. The individual encompassing this kind of a genetic marker observe an increased bitter flavor while showcasing a greater propensity to drink more coffee. Among the factors that impact food preferences and selections, the surrounding society and the availability of specific type of foods play a major part in choosing a certain food material. Upon determination of numerous associated genetic markers, the role of heredity in particular eating patterns of human beings has been disclosed. In the Central Nervous System (CNS), the genetic disparity can potentially have an impact in the degree of satiety, observation of taste, and numerous other elements that have frequent effect on food intake. In the present day, no such authenticated data or information is available for human beings in this particular range. Similarly, the nutrient absorption in human beings could also be varied or impacted. For instance, there is an elevated level of iron absorption in hemochromatosis with genetically associated mitigation of gastric intrinsic factor, eventually resulting in pernicious anemia and faulty and imperfect vitamin B12 absorption. Moreover, the innate variances in the functionality of enzymes and multiple different active proteins add to differences in nutritional specifications and preferences, leading to variable relation of specific nutrients with genetically dependent biochemical and metabolic facets. Whereas, this innate variation is relatively altered from epigenetic possibilities in numerous life stages pertaining to growth, old age, and gestation.
 In all the aspects of food selection, scientists have also taken into consideration, the role of cultural and ethnical elements. The families or relatives linked to a similar ancestor are more likely to show a bit identical genetic makeup. Ultimately, an ethnic group can be described as a comprehensive family having somewhat similar reflections. Subsequently, the uniformities of genetically dependent behaviors and disorders will be displaying a difference among different races, even among various ethnic groups of similar race. In consideration of the possibility of a racial group present in a distinct environment doesn’t really demonstrate the role of multiple genes in the ethnic or racial difference of certain traits. Furthermore, the distinction among various genetic and environmental factors can be made a lot stronger if the presence of the genes can be validated

Клинический случай эндоскопической диагностики аутоиммунного атрофического гастрита

Autoimmune atrophic gastritis (AIG) is a chronic progressive inflammatory disease that results in damage to the gastric parietal cells and replacement of these cells by atrophic and metaplastic mucosa. In the course of the disease autoantibodies gradually destroy parietal cells, causing hypochlorhydria followed by achlorhydria; vitamin B12 absorption is also impaired. The resulting cobalamin deficiency is manifested by megaloblastic anemia and neurological disorders, the combination referred to as pernicious anemia. AIG is also associated with the increased risk of gastric adenocarcinoma and gastric neuroendocrine tumors, that is why patients diagnosed with AIG should be followed-up. Since metaplastic changes in the mucous membrane are the major histological feature found in patients with autoimmune atrophic gastritis, English sources recommend to use the term “autoimmune metaplastic atrophic gastritis”. It is believed that to date AIG has been found in all populations and ethnic groups, however, there is no reliable data on the prevalence due to complexity of the diagnosis. Endoscopic diagnosis is one of the key tests for the diagnosis of AIG. The paper provides the clinical case of the endoscopic diagnosis of AIG and discusses typical endoscopic features of the disease.

467-P: The Relationship between Diabetic Peripheral Neuropathy and Metformin Treatment in Type 2 Diabetes Mellitus

Background: Metformin is the first-line therapy for the treatment of Type 2 diabetes mellitus (T2DM) . However, the use of metformin may lead to neuropathy by affecting the absorption of vitamin B12. Our objective was to explore the association between the application of metformin and diabetic peripheral neuropathy (DPN) . Methods: The multicenter randomized cross-sectional study was conducted in 13 hospitals in Beijing from October 2015 to April 2016. T2DM Patients were divided into confirmed DPN group, suspected DPN group and non-DPN group by the five physical examinations (Ankle reflex, acupuncture pain, temperature, vibration, and pressure) . Non-parametric Mann-Whitney test was used for the comparison between non-normally distributed variables between two groups. Chi-square test was used for the comparison of categorical variables. The risk factors of DPN in T2DM Patients were assessed using logistic regression. Results: Compared with patients without metformin, patients taking metformin were more likely to suffer from DPN and suspected DPN (P < 0.0for both) . Similar results were obtained after stratifying the data based on age, BMI, and HbA1c. It was shown that the application of metformin was a risk factor for DPN (OR = 5.06, 95%Cl: 3.90-6.56; P < 0.001) and suspected DPN (OR = 3.58, 95%Cl: 2.78-4.62; P < 0.001) in T2DM patients after the adjustment for age, BMI and HbA1c. In addition, prolonged application of metformin, increased cumulative and single doses would also be associated with the risk of DPN (P < 0.0for all) . Conclusion: The application of metformin was observed relate to DPN in T2DM patients. The vitamin B12 concentration and peripheral nerve function of T2DM patients with the application of metformin should be monitored. Disclosure Q.Pan: None. J.Luo: None. L.Guo: None. Funding National Key R&D Program of China (2020YFC2009006)

131-LB: Prevalence of Vitamin B12–Monitoring among Patients Receiving Metformin in a Public Hospital

Background: Metformin reduces intestinal absorption of Vitamin B12 in up to 30% of patients and lowers serum Vitamin B12 concentrations in 5-10%. In 2017, the American Diabetes Association (ADA) updated its guidelines to recommend patients taking metformin undergo regular monitoring of Vitamin B12 levels. To better understand acceptance and application of these guidelines, we undertook an assessment of such monitoring within a single hospital center serving the low-income population in Atlanta, GA to assist in guiding optimal monitoring and patient management. Methods: Data was collected from a single hospital center using electronic medical records (EMR) and the SlicerDicer tool to identify all outpatients for whom metformin was prescribed either as a single agent or in combination therapy during January 1 - December 31, 2021 and then measure Vitamin B12 prescribing among primary care patients and patients followed by endocrinology and further analyze which patients had neuropathy. Results: During the period studied, of the total 2,336,914 patients documented in the EMR, 30,803 (0.01%) were outpatients prescribed metformin either as a single agent or in combination therapy. Of these, 816 patients (2.6%) had Vitamin B12 levels ordered and measured. The prevalence of Vitamin B12 levels ordered and measured was 7.5% (674 of 8,975) among patients seen in primary care clinics and 2.3% among those followed in endocrinology (25 of 1,081) (chi-square p<0.0001) . 621 (6.9%) of the metformin-treated primary care patients had neuropathy, and of those 63 had Vitamin B12 levels. 134 (12.4%) of the endocrinology patients had neuropathy, and of those 5 had Vitamin B12 levels. (chi-square p<0.0001) Conclusion: Among two outpatient cohorts who were prescribed metformin, there was suboptimal adherence to the ADA’s recommendation for regular monitoring of Vitamin B12 levels. Approaches for increasing and optimizing ordering and monitoring Vitamin B12 levels will be developed. Increased awareness of the relationship between metformin and Vitamin B12 deficiency and standardized approaches to monitoring are needed. Disclosure R. D. Ghiya: None. M. Fayfman: None.

Metformin-induced vitamin B12 deficiency can cause or worsen distal symmetrical, autonomic and cardiac neuropathy in the patient with diabetes.

Metformin blocks the absorption of vitamin B12 through a mechanism that has not been established but could be because of interference with the calcium-dependent binding of the intrinsic factor vitamin B12 complex to the cubam receptor in the terminal ileum. The subsequent deficiency of vitamin B12 may cause or accelerate distal symmetrical and autonomic neuropathy in the patient with diabetes. Several observational studies and meta-analyses have reported a significant association between metformin utilization and vitamin B12 deficiency. Prospective studies have shown that not only do metformin utilizers have lower vitamin B12 levels but they also have higher frequencies of distal symmetrical polyneuropathy and autonomic neuropathy (including cardiac denervation, which is associated with increased incidences of cardiac arrhythmias, cardiac events and mortality). Therefore, periodic monitoring of vitamin B12 is recommended in all patients who utilize metformin, particularly if metformin has been used for over 5 years at which stage hepatic stores of vitamin B12 would probably be depleted. Factors that accelerate the loss of hepatic vitamin B12 stores are proton pump inhibitors, bariatric surgery, being elderly and having an increased turnover of red blood cells. If serum vitamin B12 levels are borderline, measurement of methylmalonic acid and homocysteine levels can detect vitamin B12 deficiency at its earliest stage. Therapies include prophylactic calcium and vitamin B12 supplements, metformin withdrawal, replenishing vitamin B12 stores with intramuscular or oral vitamin B12 therapy and regular monitoring of vitamin B12 levels and vitamin B12 supplements if metformin continues to be utilized. With adequate vitamin B12 replacement, while symptoms of neuropathy may or may not improve, objective findings of neuropathy stabilize but do not improve.

Does High Vitamin B12 Levels Cause Proteinuria?

Aim: Cubilin receptors, which are responsible for the absorption of vitamin B12 from the intestine, are also found in the kidney and regulate protein reuptake from urine. We claimed that vitamin B12 deficiency may lead to less proteinuria as a result of increased Cubilin receptors, or higher vitamin B12 levels may cause proteinuria by down regulating the receptors. To support this hypothesis, the relationship between vitamin B12 and urine protein levels was investigated. Methods: The last two-year hospital records of patients between the ages of 18-65 were retrospectively scanned. Patients who were tested for the vitamin B12, plasma creatinine, and urine protein analyses and whose eGFR value was calculated as >60mL/min were included. Patients diagnosed with diseases that may cause proteinuria such as diabetes, malignancies, or kidney diseases were excluded. Vitamin B12 level 1000 pg/ml as hypervitaminosis. Results: Of the 31,776 patients who met the criteria, vitamin B12 deficiency was found to be 38.6% in men; 33.1% in women, and 35% in total. Rates of hypervitaminosis B12 were 1.4% in both men and women, and overall. Urinary protein was observed in 13% of all patients. A statistical significance was found between vitamin B12 levels and proteinuria. In post-hoc analysis, this statistical difference was detected between the hypervitaminosis group and the other levels. Conclusion: Vitamin B12 hypervitaminosis was found to be statistically associated with proteinuria, indicating that caution should be exercised in vitamin B12 treatment. Keywords: vitamin B12, hypervitaminosis, proteinuria

CD320 expression and apical membrane targeting in renal and intestinal epithelial cells

Vitamin B12 is an essential nutrient acquired via dietary intake. Receptor-mediated endocytosis is a key mechanism in vitamin B12 absorption, cellular uptake, and reabsorption. CD320 is a type I transmembrane protein responsible for cellular uptake of vitamin B12 in peripheral tissues. In this study, we examined segmental distribution and cellular expression of CD320 in mouse kidneys and intestines. We show that CD320 is expressed on the luminal surface in the small intestine and in proximal tubules in the kidney, suggesting that, in addition to its role in vitamin B12 uptake in peripheral tissues, CD320 may participate in vitamin B12 absorption in the small intestine and reabsorption in the kidney. Moreover, we show that an amino acid motif, DSSDE, in the second low-density lipoprotein receptor class A domain of CD320 is a key apical membrane targeting signal in both renal and intestinal epithelial cells. Mutations or deletion of this motif abolish the specific apical membrane expression of CD320 in polarized Madin–Darby canine kidney cells and human colon cancer-derived Caco-2 cells. In short-hairpin RNA-based gene knockdown experiments, we show that the apical membrane targeting of CD320 is mediated by a Rab11a-dependent mechanism. These results extend our knowledge regarding the cell biology of CD320 and its role in vitamin B12 metabolism.

Endoscopic features and clinical importance of autoimmune gastritis.

Autoimmune gastritis (AIG) is a special type of chronic gastritis characterized by autoimmune disorders caused by cellular immunity, resulting in the destruction of parietal cells and production of antiparietal cell antibodies. Endoscopic findings of AIG are mainly characterized by corpus-dominant advanced atrophy. The antral area is generally considered to have no or mild atrophy; however, there are cases wherein the gastric mucosa is red or faded due to past infection with Helicobacter pylori or bile reflux. Currently, there are no diagnostic criteria for AIG in Japan, and it is important to make a diagnosis based on the presence of gastric autoantibodies and characteristic endoscopic and histological findings. AIG is associated with gastric cancer, neuroendocrine tumors (NETs), and other autoimmune diseases, such as thyroid diseases, anemia, and neurological symptoms due to impaired absorption of iron and vitamin B12 , and thus requires systemic treatment. The significance of diagnosing AIG is to include patients as a high-risk group for the development of gastric cancer and gastric NETs, provide an opportunity to detect autoimmune endocrine diseases, and initiate therapeutic intervention before anemia and neurological symptoms develop. It is important to pay close attention to the occurrence of AIG comorbidities not only at the time of AIG diagnosis but also during follow-up after detection.

A review on decreased calcium and vitamin b12 absorption with long term proton pump inhibitor therapy

Proton pump inhibitors (PPI) are now one of the most widely used classes of drugs. PPIs have proven to have a very favorable safety profile and it is unusual for a patient to stop these drugs because of side effects. However, increasing numbers of patients are chronically taking PPIs for gastro esophageal reflux disease and a number of other common persistent conditions, therefore the long-term potential adverse effects are receiving increasing attention. Nowadays as PPI are the main drugs used for peptic ulcer disease and GERD ,a part from this they are also preferred in drug induced gastric irritation .In this article these studies are systematically examined, as well as the studies of the effects of chronic PPI usage on VB12 calcium , absorption which leads to neurologic disorders and osteoporosis. In general the studies in each of three areas have led to differing conclusions, but when examined systematically, a number of the studies are showing consistent results that support the conclusion that long-term adverse effects on these processes can have important clinical implications.

Chronic Atrophic Gastritis Presenting as Hemolytic Anemia due to Severe Vitamin B12 Deficiency

Vitamin B12 is an essential nutrient which plays an important role in neurological function, hematopoiesis, and DNA synthesis. Low levels usually stem from either poor intake or a malabsorptive process. Presently, the most common cause of vitamin B12 deficiency is food-bound cobalamin malabsorption, which occurs when there is impaired release of vitamin B12 from ingested food due to an outstanding factor preventing the release of the nutrient from its transport protein. Such causes include achlorhydria, gastritis, gastrectomy, or the use of PPIs or antacids. A rarer cause is autoimmune chronic atrophic gastritis, resulting in pernicious anemia. In this disease process, there is destruction of parietal cells and thus a reduction in intrinsic factor, which is essential to the absorption of vitamin B12. Deficiency will result in a variety of abnormalities including but not limited to pancytopenia, paresthesias, and neuropsychiatric symptoms. A rare manifestation of vitamin B12 deficiency is hemolytic anemia, which occurs due to intramedullary and extramedullary dysfunction. This case describes a 46-year-old male with no past medical history who presented with chest pain, fatigue, and progressive weakness, found to have hemolytic anemia, ultimately attributed to vitamin B12 deficiency. Antiparietal cell antibodies and intrinsic factor antibodies (IFA) were both negative. Still, the patient underwent an endoscopy with biopsies of the stomach; pathology was consistent with chronic metaplastic atrophic gastritis. The patient improved with intramuscular vitamin B12 supplementation. This case highlights both a rare cause and presentation of vitamin B12 deficiency. Patients with autoimmune chronic atrophic gastritis should have antiparietal cell or intrinsic factor antibodies. Still, seronegative patients have been reported, like this patient. Additionally, hemolytic anemia secondary to vitamin B12 deficiency is uncommon. The presentation will usually mirror that of a thrombotic microangiopathy (TMA), including hemolytic anemia with schistocytes on peripheral blood smear and thrombocytopenia, as it did in this patient. This clinical entity is described as pseudothrombotic microangiopathy and is crucial to identify in order to prevent the initiation of invasive treatment strategies such as plasmapheresis.

Micronutrients deficiences in patients after bariatric surgery

Bariatric surgery is an effective option for managing obesity and has gained general acceptance among patients in recent years. Generally, despite the high caloric intake, a bad nutritional habit of obese people results in the deficiency of several vitamins, minerals, and trace elements essential for body metabolism and normal physiological processes. Additionally, the current bariatric surgical approaches such as sleeve gastrectomy (SG), Roux-en-Y-gastric bypass (RYGB), laparoscopic adjustable gastric banding (LAGB), and jejunoileal bypass (JIB) can cause or exacerbate these deficiencies. Based on several reports, it appears that the various bariatric surgical procedures affect nutrient absorption differently. Being purely restrictive, LAGB and SG affect the absorption of iron, selenium, and vitamin B12, while RYGB, JIB, and biliopancreatic diversion have a more profound impact on the absorption of essential vitamins, minerals, and trace elements. Nutritional deficiencies in vitamins, minerals, and trace elements may follow bariatric surgery and are associated with clinical manifestations and diseases, including anemia, ataxia, hair loss, and Wernicke encephalopathy. The present review summarizes some of the major vitamin and micronutrient deficiencies associated with bariatric surgery, particularly those presented post-surgically. To avoid any adverse consequences of vitamin and trace element deficiency, proper monitoring and tests are recommended at any stage, from pre- to post-surgery (periodical check-up), followed by specific and individual nutritional supplementation treatments and a proper healthy diet.

Prevalence of helicobacter pylori infection in children with Vitamin B12 Deficiency - A cross-sectional observational study

Background: Vitamin B12 deficiency is common in children but under diagnosed disorder. Helicobacter pylori infection plays an important role in the development of atrophic gastritis and related malabsorption. There may be a relationship between H.Pylori infection and vitamin B12 deficiency.
 Aims and Objective: To find out prevalence of Helicobacter pylori infection by endoscopic and histopathological findings, in children aged 2-18 years, with vitamin B12 deficiency.
 Materials and Methods: Seventy-eight patients with deficient serum vitamin B12 levels were evaluated. Upper GI Endoscopy was performed in all cases and gastric biopsies were obtained for histopathological examination and evidence of H. pylori infection.
 Results: Tissue biopsy revealed chronic atrophic gastritis in 09 patients and chronic antral gastritis in 52 patients. H. pylori infection by histology was positive in 45(57.70%) patients. We found significant correlation between atrophic gastritis and H. pylori infection, as well as between H. pylori infection and B12 deficiency.
 Conclusion: H.pylori has an effect on gastric mucosa, which affects the absorption of vitamin B12. Thus individuals with B12 deficiency should be subjected for diagnostic evaluation of H.pylori infection so that appropriate therapy can be initiated.

Imerslund-Grasbeck syndrome- a rare cause of megaloblastic anemia in an infant with homozygous mutation in CUBN gene: a case report and review of the literature

Megaloblastic anaemia is one of the important causes of pancytopenia in children and nutritional deficiencies of vitamin B12 and folate are the most common causes comprising 95% of these cases. Defects in absorption, transport and metabolism of vitamin B12 are well described, however, are very rare. We report a rare case of Imersland Grasbeck syndrome, in an infant who presented with pancytopenia, with defective absorption of B12-intrinsic factor complex at the ileum and defective tubular reabsorption of proteins in renal tubule due to same protein defect caused by mutations in two genes – CUBN (cubilin) and AMN (amnionless).

Association of MTHFR (rs 1801133) gene polymorphism with biochemical markers of B12 deficiency in type 2 diabetes mellitus patients on metformin therapy

BackgroundLong-term administration of metformin in Type 2 Diabetes mellitus (T2DM), interferes with the absorption of vitamin B12 resulting in deficiency. Low levels of vitamin B12 are associated with cardiovascular morbidity and mortality in T2DM patients. Several genetic variants are associated with vitamin B12 deficiency; one among them is Methylene Tetrahydrofolate reductase (MTHFR). We analyzed MTHFR (rs180133) polymorphism and its association with metformin induced vitamin B12 deficiency in T2DM patients. MethodsThree hundred T2DM patients were included. For the study and they were screened for vitamin B12 deficiency markers – Methyl malonic acid (MMA), Homocysteine (Hcy) and high sensitive C reactive protein (hsCRP). Genetic variant was analyzed by ARMS-PCR method. Data was analyzed with various statistical tools like ROC, Odds ratio and Likelihood ratio. ResultsThere is significant reduction in folic acid and vitamin B12 in metformin users. HsCRP, Hcy and MMA are significantly increased with P < 0.001 in patients with metformin induced B12 deficiency. T allele in MTHFR (T allele ORs =2.1, TT genotype =3.6) showed risk of vitamin B12 deficiency in T2DM patients on metformin therapy. MTHFR gene polymorphism of TT genotype had a Likelihood ratio (LR) of 2.46 for folic acid, 2.77 for MMA and 3.38 for Hcy. ConclusionWe found an association between MTHFR rs180133, 677C > T and vitamin B12 status in T2DM patients on metformin therapy. Folic acid, MMA and Hcy were found to have high specificity in concordance with MTHFR which showed to be a good predictor for vitamin B12 deficiency in T2DM patients on metformin therapy.