Vitamin B12 deficiency as a worldwide problem

From Micro to Macro: Understanding the Far-Reaching Consequences of B12 Deficiency on Women's Health

BACKGROUND

Vitamin B12 (B12), playing the role of a coenzyme in one-carbon metabolism, is an important vitamin necessary for human health.

OBJECTIVES

To systematically review evidence to identify the complications of B12 deficiency among women.

METHODS

We conducted a systematic search of quantitative studies on disorders associated with B12 deficiency among women, published in English in the last 25 years (1999-2024), using electronic databases such as Scopus, Web of science, CINAHL, PubMed, and Medline.

CONCLUSION

The search produced 28 full-text articles. B12 deficiency prevalence among women identified by the selected studies ranges from 0.6% to 45.5%. The deficiency of B12 is connected with the risk for depression/post-partum depression, breast cancer, recurrent pregnancy loss, gestational diabetes mellitus, insulin resistance, and obesity among women. It is necessary to monitor and correct the B12 deficiency among women in order to prevent complications.

Ultrasensitive detection of holoTC for analysis of Vitamin B12 levels using Ag2MoO4 deposited PEDOT sensing platform

Vitamin B12 is an essential micronutrient required for the proper functioning of the human body. Vitamin B12 deficiency is primarily causative of various neurolological disorders alongwith recurrence of oral ulcers and burning sensations which are early signs of condition such as pernicious anemia. Other complications associated with Vitamin B12 deficiency include risk of heart failure due to anemia, risk of developing autoimmune disorders and gastric cancer. Therefore, to obstruct these communal health issues, early detection of Vit B12 is highly needed. However, screening of vitamin B12 insufficiency is hindered by the low sensitivity of the conventional vitamin B12 test. Holotranscobalamin (holoTC) is an early indicator of the negative vitamin B12 balance as it is the first protein to decline in the serum. We report a novel impedimetric immunosensor based on flower-like poly (3,4-ethylenedioxythiophene) (PEDOT) nanostructural film impregnated with silver molybdate nanoparticles (Ag2MoO₄ NPs) deposited on fluorine-doped tin oxide electrode. The prepared electrodes were characterized by Field emission scanning electron microscopy (FE-SEM) with energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and electrochemical studies. The activated anti-holoTC antibody was immobilized and optimized to capture the target in a response time of 15 min. The electrochemical performance of the sensor was carried out by using the electrochemical impedance spectroscopy technique (EIS) and a good linear relationship between ΔRct and holoTC was obtained in the range from 0.1 pg mL-1 to 100 ng mL-1 with a detection limit of 0.093 pg mL-1. The proposed sensor was successfully applied in human serum samples for holoTC detection. The experimental results showed that the immunosensor is highly selective towards holoTC and presented an acceptable stability of 20 days with reproducibility RSD ≤4%. To the best of our knowledge, this is the first developed electrochemical immunosensor for holoTC detection.

Presence of vitamin B12 metabolism in the last common ancestor of land plants

Vitamin B12, also known as cobalamin, is an essential organic cofactor for methionine synthase (METH), and is only synthesized by a subset of bacteria. Plants and fungi have an alternative methionine synthase (METE) that does not need B12 and are typically considered not to utilize it. Some algae facultatively utilize B12 because they encode both METE and METH, while other algae are dependent on B12 as they encode METH only. We performed phylogenomic analyses of METE, METH and 11 further proteins involved in B12 metabolism across more than 1600 plant and algal genomes and transcriptomes (e.g. from OneKp), demonstrating the presence of B12-associated metabolism deep into the streptophytes. METH and five further accessory proteins (MTRR, CblB, CblC, CblD and CblJ) were detected in the hornworts (Anthocerotophyta), and two (CblB and CblJ) were identified in liverworts (Marchantiophyta) in the bryophytes, suggesting a retention of B12-metabolism in the last common land plant ancestor. Our data further show more limited distributions for other B12-related proteins (MCM and RNR-II) and B12 dependency in several algal orders. Finally, considering the collection sites of algae that have lost B12 metabolism, we propose freshwater-to-land transitions and symbiotic associations to have been constraining factors for B12 availability in early plant evolution. This article is part of the theme issue 'The evolution of plant metabolism'.

Biological properties of vitamin B12

Vitamin B12, cobalamin, is indispensable for humans owing to its participation in two biochemical reactions: the conversion of l-methylmalonyl coenzyme A to succinyl coenzyme A, and the formation of methionine by methylation of homocysteine. Eukaryotes, encompassing plants, fungi, animals and humans, do not synthesise vitamin B12, in contrast to prokaryotes. Humans must consume it in their diet. The most important sources include meat, milk and dairy products, fish, shellfish and eggs. Due to this, vegetarians are at risk to develop a vitamin B12 deficiency and it is recommended that they consume fortified food. Vitamin B12 behaves differently to most vitamins of the B complex in several aspects, e.g. it is more stable, has a very specific mechanism of absorption and is stored in large amounts in the organism. This review summarises all its biological aspects (including its structure and natural sources as well as its stability in food, pharmacokinetics and physiological function) as well as causes, symptoms, diagnosis (with a summary of analytical methods for its measurement), prevention and treatment of its deficiency, and its pharmacological use and potential toxicity.

Differential diagnosis of suspected multiple sclerosis: global health considerations

The differential diagnosis of multiple sclerosis can present specific challenges in patients from Latin America, Africa, the Middle East, eastern Europe, southeast Asia, and the Western Pacific. In these areas, environmental factors, genetic background, and access to medical care can differ substantially from those in North America and western Europe, where multiple sclerosis is most common. Furthermore, multiple sclerosis diagnostic criteria have been developed primarily using data from North America and western Europe. Although some diagnoses mistaken for multiple sclerosis are common regardless of location, a comprehensive approach to the differential diagnosis of multiple sclerosis in Latin America, Africa, the Middle East, eastern Europe, southeast Asia, and the Western Pacific regions requires special consideration of diseases that are prevalent in those locations. A collaborative effort has therefore assessed global differences in multiple sclerosis differential diagnoses and proposed recommendations for evaluating patients with suspected multiple sclerosis in regions beyond North America and western Europe.

Maternal Serum Folate During Pregnancy and Congenital Heart Disease in Offspring

Importance

The association of folate supplementation with congenital heart disease (CHD) prevention is controversial.

Objective

To examine the association of maternal serum folate levels at early to midpregnancy with CHD risk in offspring.

Design, Setting, and Participants

This case-control study recruited participants from one of China's largest cardiac referral centers between 2015 and 2018. CHD cases and non-CHD controls were matched according to maternal age at a ratio of 1:4. Data were analyzed from May to August 2023.

Exposures

Maternal serum levels of folate, vitamin B12, and homocysteine were measured around the gestational age of 16 weeks.

Main Outcomes and Measures

The primary outcome was CHD, which was confirmed using echocardiography. The association between CHD risk in offspring with maternal folate levels was measured using adjusted odds ratios (aORs) with 95% CIs in conditional logistic regression analyses. Interactions between folate, vitamin B12, and homocysteine and CHD were estimated on a multiplicative scale.

Results

A total of 129 CHD cases with ventricular septal defect as the most common phenotype and 516 matched controls were included. The mean (SD) maternal age at pregnancy was 31.6 (5.3) years. There was a U-shaped association between maternal serum folate levels at early to midpregnancy and CHD risk in offspring. Compared with the offspring in the second and third quartiles of maternal folate, those in the lowest (aOR, 3.09; 95% CI, 1.88-5.08) and highest quartiles (OR, 1.81; 95% CI, 1.07-3.06) had increased odds of CHD. The ORs were higher when applying the World Health Organization criteria to determine the normal range for serum folate levels. Interaction analyses suggested that the adverse associations between low and high maternal folate and CHD risk might be further magnified by vitamin B12 deficiency or elevated homocysteine.

Conclusions and relevance

In this case-control study of CHD, low maternal serum folate levels in early to midpregnancy were associated with an increased CHD risk in offspring, and excessively high folate levels were also associated with an elevated CHD risk. Further investigation is needed to make causal inferences for the observed associations and elucidate the underlying mechanisms.

Vitamin B12 status in hospitalised cancer patients: Prevalence and clinical implications of depletion and hypervitaminosis

BACKGROUND & AIMS

The prevalence and clinical significance of vitamin B12 alterations in patients with cancer are poorly understood. We aimed to assess the prevalence and risk factors of vitamin B12 depletion or hypervitaminosis in patients with cancer.

METHODS

We retrospectively included hospitalised patients with cancer in 2017-2022. Plasma B12 levels were stratified as very low (VL, <200 pg/ml), low (L, 200-299 pg/ml), normal (N, 300-812 pg/ml), or high (H, ≥813 pg/ml). We collected demographic and several clinical data (e.g., comorbidities, nutritional status, ECOG-PS, cancer site and stage). Univariate and multivariate analyses for factors associated to the vitamin B12 status were fitted.

RESULTS

788 patients (F/M ratio 1.05, median age 72 years, [25th, 75th percentiles 62, 78 years]) were included. Vitamin B12 was VL in 14.1%, L in 19.4%, N in 49.4%, and H in 17.1% cases. Vitamin B12 distribution increased significantly as function of ECOG-PS levels. Patients with breast cancer were characterized by the highest median B12 value, while colorectal cancer patients by the lowest. Vitamin B12 was also significantly higher in advanced compared to early-stage patients as well as in those who had liver failure. Multivariate analysis showed that the probability of H vs. VL B12 levels was significantly increased in patients with hypoproteinemia, hypo-prealbuminemia, and ECOG-PS≥2, and decreased in those with colorectal and gastric cancer.

CONCLUSION

Vitamin B12 impairment is common in cancer patients. Increased vitamin B12 is associated with an impaired clinical status, while vitamin B12 depletion is more common in early-stage cancer and in elderly patients.

Taurine/chenodeoxycholic acid ratio as a potential serum biomarker for low vitamin B12 levels in humans

Deficiency of vitamin B12 (B12 or cobalamin), an essential water-soluble vitamin, leads to neurological damage, which can be irreversible and anaemia, and is sometimes associated with chronic disorders such as osteoporosis and cardiovascular diseases. Clinical tests to detect B12 deficiency lack specificity and sensitivity. Delays in detecting B12 deficiency pose a major threat because the progressive decline in organ functions may go unnoticed until the damage is advanced or irreversible. Here, using targeted unbiased metabolomic profiling in the sera of subjects with low B12 levels v control individuals, we set out to identify biomarker(s) of B12 insufficiency. Metabolomic profiling identified seventy-seven metabolites, and partial least squares discriminant analysis and hierarchical clustering analysis showed a differential abundance of taurine, xanthine, hypoxanthine, chenodeoxycholic acid, neopterin and glycocholic acid in subjects with low B12 levels. Random forest multivariate analysis identified a taurine/chenodeoxycholic acid ratio, with an AUC score of 1, to be the best biomarker to predict low B12 levels. Mechanistic studies using a mouse model of B12 deficiency showed that B12 deficiency reshaped the transcriptomic and metabolomic landscape of the cell, identifying a downregulation of methionine, taurine, urea cycle and nucleotide metabolism and an upregulation of Krebs cycle. Thus, we propose taurine/chenodeoxycholic acid ratio in serum as a potential biomarker of low B12 levels in humans and elucidate using a mouse model of cellular metabolic pathways regulated by B12 deficiency.

Oral vitamin B12 supplementation in pernicious anemia: a prospective cohort study

BACKGROUND

The absorption of vitamin B12 is hindered in pernicious anemia (PA) owing to intrinsic factor deficiency. Traditionally, intramuscular vitamin B12 injections were the standard treatment, bypassing the impaired absorption. Although there is potential for oral vitamin B12 supplementation through passive enteral absorption, it is not commonly prescribed in PA owing to limited studies assessing its efficacy.

OBJECTIVES

We aimed to assess the efficacy of oral vitamin B12 supplementation in PA.

METHODS

We enrolled participants diagnosed with incident vitamin B12 deficiency related to PA. The diagnosis of PA was based on the presence of classical immune gastritis and of anti-intrinsic factor and/or antiparietal cell antibodies. To evaluate the vitamin B12 status, we measured total plasma vitamin B12, plasma homocysteine, and plasma methylmalonic acid (pMMA) concentration and urinary methylmalonic acid-to-creatinine ratio. Participants were treated with oral cyanocobalamin at a dosage of 1000 μg/d throughout the study duration. Clinical and biological vitamin B12 deficiency related features were prospectively and systematically assessed over the 1-y study duration.

RESULTS

We included 26 patients with vitamin B12 deficiency revealing PA. Following 1 mo of oral vitamin B12 supplementation, 88.5% of patients were no longer deficient in vitamin B12, with significant improvement of plasma vitamin B12 [407 (297-485) compared with 148 (116-213) pmol/L; P < 0.0001], plasma homocysteine [13.5 (10.9-29.8) compared with 18.6 (13.7-46.8) μmol/L; P < 0.0001], and pMMA [0.24 (0.16-0.38) compared with 0.56 (0.28-1.09) pmol/L; P < 0.0001] concentrations than those at baseline. The enhancement of these biological parameters persisted throughout the 12-month follow-up, with no patients showing vitamin B12 deficiency by the end of the follow-up period. The median time to reverse initial vitamin B12 deficiency abnormalities ranged from 1 mo for hemolysis to 4 mo for mucosal symptoms.

CONCLUSIONS

Oral supplementation with 1000 μg/d of cyanocobalamin has been shown to improve vitamin B12 deficiency in PA.

Green strength: The role of micronutrients in plant-based diets for athletic performance enhancement

This review examines the correlation between plant-based diets and athletic performance, with a specific emphasis on the vital aspect of optimizing micronutrients for athletes. In light of the increasing prevalence of plant-based nutrition among athletes due to its perceived advantages in terms of health, ethics, and the environment, this study investigates the ability of these diets to satisfy the demanding nutritional requirements essential for achieving optimal performance and facilitating recovery. The article emphasizes the significance of essential micronutrients such as iron, vitamin B12, calcium, vitamin D, zinc, and omega-3 fatty acids and also addressing the challenges with their absorption and bioavailability from plant sources. The review consolidates existing scientific knowledge to propose strategies for improving micronutrient consumption, comparing the effects of supplements against whole foods, and highlighting the significance of enhancing bioavailability. The proposal supports the implementation of personalized meal planning, with the assistance of sports nutritionists or dietitians, and is substantiated by case studies showcasing the success of plant-based athletes. Future research directions examine the long-term effects of plant-based diets on micronutrient status and athletic performance, as well as developing nutritional trends and technology. The review concludes that plant-based diets can meet athletes' nutritional demands and improve peak performance while aligning with personal and ethical values with strategic planning and professional guidance. This study intends to help athletes, coaches, and nutritionists understand plant-based nutrition for enhanced athletic performance.

Influence of folic acid and vitamin B12 supplementation on arsenic methylation: A double-blinded, placebo-controlled trial in Bangladeshi children

BACKGROUND

Inorganic arsenic is metabolized to monomethyl- (MMAs) and dimethyl- (DMAs) species via one-carbon metabolism (OCM); this facilitates urinary arsenic elimination. OCM is influenced by folate and vitamin B12 and previous randomized control trials (RCTs) showed that folic acid (FA) supplementation increases arsenic methylation in adults. This RCT investigated the effects of FA + B12 supplementation on arsenic methylation in children, a key developmental stage where OCM supports growth.

METHODS

A total of 240 participants (8-11 years, 53 % female) drinking from wells with arsenic concentrations > 50 μg/L, were encouraged to switch to low arsenic wells and were randomized to receive 400 μg FA + 5 μg B12 or placebo daily for 12-weeks. Urine and blood samples were collected at baseline, week 1 (only urine) and week 12. Generalized estimated equation (GEE) models were used to assess treatment effects on arsenic species in blood and urine.

RESULTS

At baseline, the mean ± SD total blood and urinary arsenic were 5.3 ± 2.9 μg/L and 91.2 ± 89.5 μg/L. Overall, total blood and urine arsenic decreased by 11.7% and 17.6%, respectively, at the end of follow up. Compared to placebo, the supplementation group experienced a significant increase in the concentration of blood DMAs by 14.0% (95% CI 5.0, 25.0) and blood secondary methylation index (DMAs/MMAs) by 0.19 (95% CI: 0.09, 0.35) at 12 weeks. Similarly, there was a 1.62% (95% CI: 0.43, 20.83) significantly higher urinary %DMAs and -1.10% (95% CI: -1.73, -0.48) significantly lower urinary %MMAs in the supplementatio group compared to the placebo group after 1 week. The direction of the changes in the urinary %iAs, %MMAs, and %DMAs at week 12 were consistent with those at week 1, though estimates were not significant. Treatment effects were stronger among participants with higher baseline blood arsenic concentrations. Results were consistent across males and females, and participants with higher and lower folate and B12 status at baseline.

CONCLUSION

This RCT confirms that FA + B12 supplementation increases arsenic methylation in children as reflected by decreased MMAs and increased DMAs in blood and urine. Nutritional interventions may improve arsenic methylation and elimination in children, potentially reducing arsenic toxicity while also improving nutritional status.

Vitamin B12 deficiency presenting as neck pain and cervical radiculopathy

Vitamin B12 is required for the formation of haematopoietic cells and the synthesis of myelin. Deficiency typically presents with fatigue and megaloblastic anaemia. Prolonged deficiency can cause neurological symptoms such as paresthesia, which can progress to subacute combined degeneration of the spinal cord. We describe an unusual presentation of B12 deficiency in a young man who was initially diagnosed and treated for cervical radiculopathy. This case highlights the challenges of diagnosing B12 deficiency in patients with neurologic but without haematologic, abnormalities. While the current incidence of B12 deficiency in developed countries is low, cases are likely to rise with the increased adoption of veganism. Clinicians should be aware of the variable presentations of B12 deficiency because delayed diagnosis and treatment increases morbidity and can cause irreversible neurological deficits.

Dietary supplement use among lactating mothers following different dietary patterns - an online survey

BACKGROUND

Breastfeeding is important for the healthy growth and development of newborns, and the nutrient composition of human milk can be affected by maternal nutrition and supplementation. In Germany, iodine supplementation is recommended for all lactating mothers, and docosahexaenoic acid (DHA) supplementation is recommended for mothers with inadequate or no fish intake. Vitamin B12 supplementation is required for strict vegans during lactation, and other nutrient supplementation may be necessary depending on the individual's nutritional status. To address the lack of data on dietary supplements used by lactating mothers following a vegetarian or vegan diet, an online survey was conducted in Germany, with a focus on iodine, DHA, and vitamin B12.

METHODS

Study participants were asked to report whether they followed specific dietary patterns (omnivorous [OM], vegetarian [VT], vegan [VN]) as well as their use of dietary supplements. Relationships between diets and supplement use were analyzed using chi-square tests.

RESULTS

2054 lactating women were included (1240 OM, 410 VT, and 404 VN) in this analysis. Within OM, VT and VN, at least one dietary supplement was taken by 67.3%, 84.9% and 98.0% respectively (p < 0.001). Overall, 53.2% OM, 66.8% VT, 88.4% VN reported taking at least one supplement containing iodine (p < 0.001). 54.6% OM, 61.7% VT and 58.2% VN reported supplements containing vitamin B12, while 34.1% OM, 40.2% VT and 38.6% VN mentioned supplements containing DHA (p < 0.05).

CONCLUSION

More than half of the participants reported the use of supplements during lactation with the highest proportion in vegans. However, over one third of the mothers did not report supplementing with iodine, regardless of their dietary pattern and most participants also did not report DHA supplements. It is worrisome that a high number of vegans did not report vitamin B12 supplementation, but this could be partly due to issues with reporting. It is crucial to provide further education to breastfeeding mothers about the importance of taking micronutrient supplements, especially for those following a vegetarian or vegan diet. This will help ensure that mothers and their breastfed infants receive optimal nutrition for a healthy development.

Hunger in French Guiana, an endemic plague worsened by the health crisis

In 2020, food shortages occurred at the beginning of the confinement period that was supposed to curb the COVID-19 pandemic. In French Guiana, where a major part of the population lives under the poverty line, health workers voiced major concerns. Alongside massive food aid distributions, a first transversal study was carried out in August 2020 targeting poor neighborhoods in Cayenne. The results were particularly worrying. More than 80% of households had been suffering from hunger during that month, with a median decrease of 46% in revenue. Two other investigations followed in February and then in August of 2021. With the relaxing of the health measures, the situation improved in the Cayenne region, but two out of three were still affected, showing signs of quantitative deficiencies and insufficient food diversity. The situation seemed particularly grave for children. In light of this situation, we propose to create an observatory of food insecurity in Guiana, while maintaining this topic as a health priority. In addition, the fight against food insecurity cannot be limited to multi-sectorial material and strategic aide. It must be thought about in a more global manner, including health and social questions, territorial management policies, access to land and water, access to rights and social inclusion. Targeted actions helping the most exposed and vulnerable people is also an important stake, independent of the administrative situation and residency rights of the concerned people.

Vitamin B12 insufficiency and deficiency: a review of nondisease risk factors

Vitamin B12 deficiency and insufficiency can lead to both hematological and neurological impairments. This review examines nondisease causes and risk factors associated with dietary availability, such as eating habits, food processing, cooking techniques, and bioavailability, as well as increased physiological needs and iatrogenic factors linked to medication use or surgical procedures. As a result of these nondisease influences, groups at higher risk include vegans, vegetarians, older adults, individuals with limited diets, breastfed and preterm infants, and those who primarily consume foods prepared or cooked in ways that reduce vitamin B12 content, as well as individuals on certain medications or who have undergone specific surgeries. Recognizing these diverse risk factors helps develop strategies for prevention and intervention to minimize the adverse health effects related to B12 deficiency and insufficiency.

Cereal-based fermented foods as a source of folate and cobalamin: The role of endogenous microbiota

Folate (vitamin B9) and cobalamin (vitamin B12) deficiencies potentially affect millions of people worldwide, leading to different pathologies. In Ethiopia, the diet is characterized by high consumption of fermented cereal-based foods such as injera, a good source of folate but not of cobalamin, which is only found in foods of animal origin that are rarely consumed. Some of the bacteria responsible for the fermentation of cereals can synthesize cobalamin, but whether or not fermented cereal food products contain cobalamin remains underexplored. The objective of this study was to assess the folate and cobalamin content of injera collected from various households in Ethiopia at different stages of production. Global (16S rRNA gene sequencing) and specific (real-time PCR quantification of bacteria known for folate or cobalamin production) bacterial composition of these samples was assessed. UPLC-PDA was used to identify the cobalamin to see whether the active or inactive form was present. Surprisingly, teff flour contained 0.8 μg/100 g of cobalamin, most probably due to microbial contamination from the environment and the harvesting process. While fermentation increased the folate and cobalamin content in some households, their levels decreased in others. Conversely, cooking consistently reduced the level of the vitamins. Fresh injera contained, on average, 21.2 μg/100 g of folate and 2.1 μg/100 g of cobalamin, which is high, but with marked variation depending on the sample. However, the form of cobalamin was a corrinoid that is biologically inactive in humans. Injera fermentation was dominated by lactic acid bacteria, with significant correlations observed between certain bacterial species and folate and cobalamin levels. For example, a high proportion of Fructilactobacillus sanfranciscensis, a known folate consumer, was negatively correlated with the folate content of injera. On the contrary, Lactobacillus coryniformis, known for its cobalamin synthesis ability was present in high proportion in the cobalamin-rich samples. These findings highlight the complex interrelationship between microorganisms and suggest the involvement of specific bacteria in the production of folate and cobalamin during injera fermentation. Controlled fermentation using vitamin-producing bacteria is thus a promising tool to promote folate and cobalamin production in fermented food.

The Epidemiology of Deficiency of Vitamin B12 in Preschool Children in Turkey

Background: Vitamin B12 is a water-soluble vitamin with important cellular functions; it is an essential vitamin. The aim of this study is to determine the B12 levels of children in the period from the 6th month when they start taking additional foods to the age of seven (preschool children) and the risk factors affecting them. Methods: One hundred pediatric patients aged 6-72 months who were diagnosed with vitamin B12 deficiency and their parents who agreed to attend Istanbul Atlas University, Medical Faculty, "Medicine Hospital" Pediatric Clinic between September 2022 and June 2023 were prospectively included in this study. Results: B12 deficiency was significantly higher in the 6-11 (25%)-month group than in the 12-23 (5.8%)- and 24-47 (2.8%)-month groups. Homocysteine levels were highest in those with insufficient B12 levels compared to the other groups. There was no statistically significant difference in weekly dairy and meat consumption levels between age groups. B12 levels were lower in the 6-11-month group than in the other groups. Homocysteine levels were highest in those with insufficient B12 levels (<200 pg/mL (148 pmol/L)). Folic acid levels were lower in the 24-47-month and 48-72-month groups than in the 6-11-month and 12-23-month groups. Conclusions: The results obtained in this study showed that low vitamin B12 and increased homocysteine levels seem to be important risk factors in preschool children, especially from the 6th month when they start consuming additional foods. The diagnosis of B12 deficiency can be confirmed by elevated serum total homocysteine levels, which are evidence of functional cobalamin deficiency.

Vitamin B12 deficiency in an infant with neurological and hematological findings: A case report

Key Clinical Message

It is important for pregnant and breastfeeding women who adhere to a strict vegetarian diet to take appropriate steps to avoid vitamin B12 deficiency in their infants.

Abstract

Vitamin B12 deficiency is rare during infancy. The initial symptoms of this deficiency are subtle and may include irritability, failure to thrive with a decline in growth rate, apathy, anorexia, refusal of solid foods, megaloblastic anemia, and developmental regression. The case presented here involves an 8-month-old male infant who showed neurological symptoms such as decreased activity, increased drowsiness, and reduced interaction with parents, which were ultimately linked to a deficiency of cobalamin (vitamin B12). Early recognition of this condition is critical because it is reversible. Therefore, pregnant and lactating women who follow a strict vegetarian diet should take necessary measures to prevent vitamin B12 deficiency in infants.

Early Detection of Subclinical Atherosclerosis: Hyperhomocysteinemia as a Promising Marker in Adolescents With Vitamin B Deficiency

In recent decades, the increased incidence of cardiovascular disease (CVD) mortality among young adults has raised concerns. Although clinical manifestations of CVD typically occur later in life, the underlying pathological processes emerge early on. This review article summarizes the association between vitamin B deficiency-induced hyperhomocysteinemia and subclinical atherosclerosis in adolescents. Numerous studies have demonstrated that elevated homocysteine levels are an independent risk factor for endothelial dysfunction (ED) and arterial stiffness, which are key contributors to CVD. Notably, vitamin B deficiency, particularly in vitamin B9 and vitamin B12, emerges as a significant factor in childhood hyperhomocysteinemia, initiating the development of subclinical atherosclerosis in early life. A comprehensive review of relevant literature from prominent bibliographic databases, including PubMed/MEDLINE, PubMed Central, Google Scholar, and Cochrane, was performed. Four cross-sectional studies focusing on homocysteine levels as an exposure variable and markers of atherosclerosis as outcome measures were included and reviewed as part of our analysis. The reviewed studies demonstrate a positive correlation between homocysteine levels and markers of atherosclerosis, including increased carotid intima-media thickness (CIMT) and ED. Mainly, adolescents with vitamin B12 deficiency exhibit a significant positive correlation between homocysteine levels and CIMT. These findings underscore the potential of hyperhomocysteinemia as an early marker for detecting subclinical atherosclerosis in adolescents with vitamin B deficiency. Despite limited research in this area, recognizing the importance of early detection and management of subclinical atherosclerosis in adolescents can help mitigate the risk of severe cardiovascular events such as myocardial infarction and stroke in young adulthood.

A case of subacute combined degeneration of the spinal cord diagnosed with difficulty due to a history of treatment for pyogenic spondylitis

Early diagnosis of spinal cord subacute combined degeneration (SCD) is difficult, especially in pre-existing lower extremity impairment cases. We report a case of progressive SCD diagnosed after severe anemia. The peripheral symptoms of SCD other than gait disturbance should also be well understood and given close attention.

Nutritional Assessment of the Symptomatic Patient on a Plant-Based Diet: Seven Key Questions

Plant-based diets, both vegan and vegetarian, which emphasize grains, vegetables, fruits, legumes, nuts, and seeds are increasingly popular for health as well as financial, ethical, and religious reasons. The medical literature clearly demonstrates that whole food plant-based diets can be both nutritionally sufficient and medically beneficial. However, any person on an intentionally restrictive, but poorly-designed diet may predispose themselves to clinically-relevant nutritional deficiencies. For persons on a poorly-designed plant-based diet, deficiencies are possible in both macronutrients (protein, essential fatty acids) and micronutrients (vitamin B12, iron, calcium, zinc, and vitamin D). Practitioner evaluation of symptomatic patients on a plant-based diet requires special consideration of seven key nutrient concerns for plant-based diets. This article translates these concerns into seven practical questions that all practitioners can introduce into their patient assessments and clinical reasoning. Ideally, persons on plant-based diets should be able to answer these seven questions. Each serves as a heuristic prompt for both clinician and patient attentiveness to a complete diet. As such, these seven questions support increased patient nutrition knowledge and practitioner capacity to counsel, refer, and appropriately focus clinical resources.

Effects of B12 Deficiency Anemia on Radial Peripapillary and Macular Vessel Density: An Optical Coherence Tomography Angiography (OCTA) Study

BACKGROUND

To evaluate the macular and optic disc vascular changes in vitamin B12 deficiency anemia.

METHODS

A total of 24 patients with vitamin B12 deficiency anemia and 24 healthy controls were involved in this study. All participants were evaluated for central macular thickness (CMT), peripapillary retina nerve fiber layer (RNFL) thickness, foveal avascular zone (FAZ) area, macular vessel density (VD) in superficial capillary plexus (SCP) and deep capillary plexus (DCP), choriocapillaris flow area, and optic disc radial peripapillary capillary (RPC) VD using optic coherence tomography (OCT) and optic coherence tomography angiography (OCTA). Metabolic parameters were also noted.

RESULTS

Temporal RNFL thickness significantly decreased in the B12 deficiency anemia group (p = 0.04). Choriocapillaris flow area (p = 0.045) and macular vessel density in both SCP (p = 0.022) and DCP (p = 0.018) markedly declined in the study group. Optic disc RPC VD in the B12 deficiency anemia group was lower in all regions compared to that of the control group, but the difference was not statistically significant (p > 0.05). There were significant positive correlations between choriocapillaris flow area, macular VD, vitamin B12, and hemoglobin.

CONCLUSION

Retinal vascular alterations were observed in B12 deficiency anemia, and OCTA may be beneficial in the diagnosis and follow-up of ocular complications in these cases.

Intermediate role of gut microbiota in vitamin B nutrition and its influences on human health

Vitamin B consists of a group of water-soluble micronutrients that are mainly derived from the daily diet. They serve as cofactors, mediating multiple metabolic pathways in humans. As an integrated part of human health, gut microbiota could produce, consume, and even compete for vitamin B with the host. The interplay between gut microbiota and the host might be a crucial factor affecting the absorbing processes of vitamin B. On the other hand, vitamin B supplementation or deficiency might impact the growth of specific bacteria, resulting in changes in the composition and function of gut microbiota. Together, the interplay between vitamin B and gut microbiota might systemically contribute to human health. In this review, we summarized the interactions between vitamin B and gut microbiota and tried to reveal the underlying mechanism so that we can have a better understanding of its role in human health.

Low-fat fresh sausage from rabbit meat: An alternative to traditional rabbit consumption

The study aimed at the development of fresh sausages using rabbit exclusively as raw material. The idea was to offer an innovative product to increase rabbit consumption. Also, to meet currently consumers' requirements, a low-fat version was made. Two final formulations, a control sausage and a low-fat version using konjac gum, were developed through an iterative process and stored in a MAP under refrigeration. Sensory, microbiological and physicochemical analyses were carried out on days 1, 6, 8 and 13 after packaging. The shelf-life of the sausages was determined according to a multivariate criterion. Results showed a significant reduction in fat content and energy value. Sensory analysis showed a decrease in characteristic aroma and flavour and an increase in rancid odour, while hardness and fragility decreased in the low-fat treatment. The shelf-life was 7 days for all treatments, concluding that the multivariate method was a powerful technique as physicochemical, microbiological and sensory criteria were considered.

The silent tragic reality of Hidden Hunger, anaemia, and neural-tube defects (NTDs) in India

Hidden Hunger arising from nutritional iron-, folate-, and vitamin-B₁₂-deficiencies is exceedingly common in India and has profound negative impacts on anaemia, on pregnancy, and on embryonic-foetal neurodevelopment in utero, which predisposes to NTDs and psychological-psychiatric manifestations in childhood. Whereas younger-to-middle-aged Indians fail to perform at maximum potential, the elderly are at risk for calamitous neurologic events. However, these micronutrient-deficiencies are eminently correctable through food-fortification. Therefore, the Indian Government can no longer afford the luxury of inaction by either denying or downplaying the gravity of this problem. What is critically needed from India's leaders is an urgent, clear-eyed reappraisal and act of anagnorisis-(an often startling self-recognition and discovery of a profoundly serious error and tragic flaw)-in failing to confront this problem for decades. Only when closely followed by a metanoia-(a transformative change of heart that triggers remedial action)-can they help India avoid a catastrophic tryst with destiny.

Vitamin B12 deficiency may play an etiological role in atrophic glossitis and its grading: A clinical case-control study

Background

Existing studies have reported the significant association between atrophic glossitis (AG) and hematinic deficiencies, including iron, folate and vitamin B12 deficiency. However, these findings were inconsistent. AG can be graded as partial or complete atrophy. It is still unclear whether hematinic deficiencies are associated with the grading of AG.

Methods

236 AG patients and 208 sex- and age-matched healthy controls were enrolled in this study. Hematological tests including complete blood count, and serum levels of folate, ferritin and vitamin B12 were performed. The AG group was divided into those with partial AG and those with complete AG according to the extent of papillary atrophy. Statistical analysis was performed to assess whether hematinic deficiencies are risk factors for AG and its grading.

Results

Compared with the healthy controls, AG patients had significantly higher frequencies of vitamin B12 deficiency (68.22%), ferritin deficiency (13.98%) and anemia (21.61%). The differences in hematinic deficiencies and anemia between AG patients and healthy controls changed according to gender and age. The frequencies of serum vitamin B12 deficiency and anemia in the complete AG subgroup were significantly higher than those in the partial AG subgroup. Logistic regression analysis revealed that vitamin B12 deficiency and anemia were significantly correlated with AG and its grading. The AG patients with vitamin B12 deficiency responded well to supplement therapy.

Conclusion

AG could be an important clinical indicator for potential vitamin B12 deficiency, especially when the degree of tongue atrophy more than 50% and complete atrophy. Vitamin B12 deficiency might play an etiological role in the development of AG.

Acquired Vitamin B12 Deficiency in Newborns: Positive Impact on Newborn Health through Early Detection

The early diagnosis of and intervention in vitamin B12 deficiency in exclusively breastfed infants by mothers with low vitamin B12 is crucial in preventing possible irreversible neurologic damage, megaloblastic anemia, and failure to thrive. We assess the usefulness of the early detection of asymptomatic B12 deficiency related to acquired conditions and highlight the importance of monitoring serum vitamin B12 levels during pregnancy. We describe demographic, clinical, dietary, and biochemical data, including the evolution of a vitamin B12 deficiency’s functional biomarkers. We enrolled 12 newborns (5 males) with an age range of 1–2 months old that were exclusively breastfed and asymptomatic. These cases were referred to our metabolic unit due to alterations in expanded newborn screening: high levels of methylmalonic acid and/or total homocysteine (tHcy). All mothers were under a vegetarian diet except three who had abnormal B12 absorption, and all presented low or borderline serum B12 level and high plasma levels of tHcy. Supplementation with oral vitB12 re-established the metabolic homeostasis of the mothers. In infants, therapy with an intramuscular injection of 1.0 mg hydroxocobalamin led to the rapid normalization of the metabolic pattern, and a healthy outcome was observed. Acquired B12 deficiency should be ruled out before proceeding in a differential diagnosis of cobalamin metabolism deficits, methylmalonic acidemia, and homocystinuria.

Nutrient smuggling: Commensal gut bacteria-derived extracellular vesicles scavenge vitamin B12 and related cobamides for microbe and host acquisition

The processes by which bacteria proactively scavenge essential nutrients in crowded environments such as the gastrointestinal tract are not fully understood. In this context, we observed that bacterial extracellular vesicles (BEVs) produced by the human commensal gut microbe Bacteroides thetaiotaomicron contain multiple high-affinity vitamin B12 binding proteins suggesting that the vesicles play a role in micronutrient scavenging. Vitamin B12 belongs to the cobamide family of cofactors that regulate microbial communities through their limited bioavailability. We show that B. thetaiotaomicron derived BEVs bind a variety of cobamides and not only deliver them back to the parental bacterium but also sequester the micronutrient from competing bacteria. Additionally, Caco-2 cells, representing a model intestinal epithelial barrier, acquire cobamide-bound vesicles and traffic them to lysosomes, thereby mimicking the physiological cobalamin-specific intrinsic factor-mediated uptake process. Our findings identify a novel cobamide binding activity associated with BEVs with far-reaching implications for microbiota and host health.

Maternal Vitamin B12 Deficiency Detected by Newborn Screening-Evaluation of Causes and Characteristics

Vitamin B12 deficiency, mostly of maternal origin in newborns, is a well-treatable condition but can cause severe neurologic sequelae in infants. Early detection of vitamin B12 deficiency allows the pre-symptomatic treatment of affected children. This evaluation assesses the characteristics of maternal vitamin B12 deficiency detected by newborn screening. In a prospective single-center study, a systematic screening strategy for vitamin B12 deficiency using a combination of two second-tier strategies was applied. In addition to confirmatory diagnostics in children, the systematic work-up of vitamin B12 status was also performed for their mothers. Maternal characteristics were assessed including ethnic origin, diet, and vitamin supplementation during pregnancy. For affected mothers, a work-up by internal medicine was recommended. In total, 121 mother-infant couples were analyzed. 66% of mothers adhered to a balanced diet including meat. The cause of maternal vitamin B12 deficiency was unknown in 56% of cases, followed by dietary causes in 32%, and organic causes in 8%. All mothers following a vegan diet and most mothers with a vegetarian diet took vitamin preparations during pregnancy, whereas only 55.8% of mothers with a balanced diet took folic acid or other vitamins. Maternal vitamin B12, folic acid, and homocysteine levels were significantly correlated with the child's folic acid levels, and with homocysteine, methylmalonic, and methylcitric acid levels in first and second NBS dried blood spots. Most children had normal blood counts and showed normocytosis. Although 36.7% of mothers showed anemia, only one presented with macrocytosis. Adherence to vitamin supplementation in pregnancy is low despite the recommendation for supplementation of folic acid. Ideally, the evaluation of mothers for vitamin B12 levels and appropriate therapy should be initiated in early pregnancy. In infants detected through newborn screening, the multidisciplinary assessment and therapy of both children and mothers should be performed.

Autoimmune gastritis in a male adolescent with cerebellar involvement: A case report

Introduction

Autoimmune gastritis is an immune mediated disorder characterized as anti-intrinsic factor and anti-parietal cell autoantibodies directed against intrinsic factor and parietal cells of the stomach respectively, leading to vitamin B12 deficiency. When the disease remains undiagnosed and untreated, it may lead to neurological complications and even fatal anemia.

Case study

We exemplify a non-vegetarian male adolescent case with the neurological symptoms such as bilateral leg weakness, unsteady gait, slurred speech, vertigo, slowed movement, lethargy, and impaired joint sensation. None of his family members had such illness. His hemoglobin was normal with serum vitamin B12 level 105 pg/mL and anti-intrinsic factor antibody titer positive. A presumed diagnosis of cobalamin deficiency with involvement of the cerebellum, dorsal column and peripheral nerves was made. His symptoms recovered gradually and later completely (after 6 months) after the intramuscular vitamin B12 therapy.

Clinical discussion

The indexed rare adolescent case had auto immune gastritis showing neurological manifestation with more pronounced cerebellar features and vitamin B12 deficiency under the non-vegetarian diet consumption. Previous studies had reflected auto immune among adolescents but contrasted some of the clinical features.

Conclusion

For the prompt and precise diagnosis of the autoimmune gastritis and to prevent further complications, some of the rare conditions such as deficiency with a non-vegetarian diet, neurological manifestation including cerebellar involvement without anemia should also be considered along with other relevant symptoms. The heightened awareness for timely surveillance and treatment will contribute in reduction of such unusual cases.

Unusual Derivatization of Methylmalonic Acid with Pentafluorobenzyl Bromide to a Tripentafluorobenzyl Derivative and Its Stable-Isotope Dilution GC-MS Measurement in Human Urine

Methylmalonic acid (MMA) is a very short dicarboxylic acid (methylpropanedioic acid; CH₃CH(COOH)₂; pK_a1, 3.07; pK_a2, 5.76) associated with vitamin B₁₂ deficiency and many other patho-physiological conditions. In this work, we investigated several carboxylic groups-specific derivatization reactions and tested their utility for the quantitative analysis of MMA in human urine and plasma by gas chromatography-mass spectrometry (GC-MS). The most useful derivatization procedure was the reaction of unlabeled MMA (d₀-MMA) and trideutero-methyl malonic acid (d₃-MMA) with 2,3,4,5,6-pentafluorobenzyl bromide (PFB-Br) in acetone. By heating at 80 °C for 60 min, we observed the formation of the dipentafluorobenzyl (PFB) ester of MMA (CH₃CH(COOPFB)₂). In the presence of N,N-diisopropylamine, heating at 80 °C for 60 min resulted in the formation of a tripentafluorobenzyl derivative of MMA, i.e., CH₃CPFB(COOPFB)₂). The retention time was 5.6 min for CH₃CH(COOPFB)₂ and 7.3 min for CH₃CPFB(COOPFB)₂). The most intense ions in the negative-ion chemical ionization (NICI) GC-MS spectra of CH₃CH(COOPFB)₂ were mass-to-charge (m/z) 233 for d₀-MMA and m/z 236 for d₃-MMA. The most intense ions in the NICI GC-MS spectra of CH₃CPFB(COOPFB)₂ were mass-to-charge (m/z) 349 for d₀-MMA and m/z 352 for d₃-MMA. These results indicate that the H at C atom at position 2 is C-H acidic and is alkylated by PFB-Br only in the presence of the base N,N-diisopropylamine. Method validation and quantitative analyses in human urine and plasma were performed by selected ion monitoring (SIM) of m/z 349 for d₀-MMA and m/z 352 for the internal standard d₃-MMA in the NICI mode. We used the method to measure the urinary excretion rates of MMA in healthy black (n = 39) and white (n = 41) boys of the Arterial Stiffness in Offspring Study (ASOS). The creatinine-corrected excretion rates of MMA were 1.50 [0.85–2.52] µmol/mmol in the black boys and 1.34 [1.02–2.18] µmol/mmol in the white boys (P = 0.85; Mann–Whitney). The derivatization procedure is highly specific and sensitive for MMA and allows its accurate and precise measurement in 10-µl of human urine by GC-MS.

Could microalgae offer promising options for climate action via their agri-food applications?

In 2021 the Intergovernmental Panel on Climate Change (IPCC) issued the first volume of its latest authoritative report on climate change. Underlining the seriousness of the situation, the United Nations Secretary-General branded its findings a “code red for humanity.” The need for climate action is now evident, but finding viable pathways forward can be elusive. Microalgae have been attracting attention as a category of “future food,” with species like Arthrospira platensis (spirulina) and Chlorella vulgaris (chlorella) seeing growing uptake by consumers while research interest continues to expand. One timely but neglected question is whether microalgae might offer options for promising climate actions via their agri-food applications. Specifically, might they offer scope to help secure food supplies, while also providing climate resilient livelihood pathways for vulnerable farmers already grappling with food insecurity and environmental degradation? This paper reports on a review of the academic literature on microalgae as an agri-food technology, notably their uses as a food, feed, biofertilizer, biostimulant, and biochar. This family of applications was found to offer promising climate actions vis-à-vis both mitigating and adapting to climate change. Aspects pertinent to adaptation include growing rapidly under controlled conditions, reusing water, providing potent nutrition for humans and animals, and supporting resilient crop production. Agri-food applications of microalgae also provide opportunities to mitigate climate change that could be explored. The paper concludes by flagging possible risks and obstacles as well as research and policy priorities to elaborate and harness this potential.

Vitamin B12 coordinates ileal epithelial cell and microbiota functions to resist Salmonella infection in mice

Deprivation of vitamin B12 (VB12) is linked to various diseases, but the underlying mechanisms in disease progression are poorly understood. Using multiomic approaches, we elucidated the responses of ileal epithelial cells (iECs) and gut microbiome to VB12 dietary restriction. Here, VB12 deficiency impaired the transcriptional and metabolic programming of iECs and reduced epithelial mitochondrial respiration and carnitine shuttling during intestinal Salmonella Typhimurium (STm) infection. Fecal microbial and untargeted metabolomic profiling identified marked changes related to VB12 deficiency, including reductions of metabolites potentially activating mitochondrial β-oxidation in iECs and short-chain fatty acids (SCFAs). Depletion of SCFA-producing microbes by streptomycin treatment decreased the VB12-dependent STm protection. Moreover, compromised mitochondrial function of iECs correlated with declined cell capability to utilize oxygen, leading to uncontrolled oxygen-dependent STm expansion in VB12-deficient mice. Our findings uncovered previously unrecognized mechanisms through which VB12 coordinates ileal epithelial mitochondrial homeostasis and gut microbiota to regulate epithelial oxygenation, resulting in the control of aerobic STm infection.

Pernicious Anemia: The Hematological Presentation of a Multifaceted Disorder Caused by Cobalamin Deficiency

Pernicious anemia is still a neglected disorder in many medical contexts and is underdiagnosed in many patients. Pernicious anemia is linked to but different from autoimmune gastritis. Pernicious anemia occurs in a later stage of autoimmune atrophic gastritis when gastric intrinsic factor deficiency and consequent vitamin B₁₂ deficiency may occur. The multifaceted nature of pernicious anemia is related to the important role of cobalamin, which, when deficient, may lead to several dysfunctions, and thus, the proteiform clinical presentations of pernicious anemia. Indeed, pernicious anemia may lead to potentially serious long-term complications related to micronutrient deficiencies and their consequences and the development of gastric cancer and type 1 gastric neuroendocrine tumors. When not recognized in a timely manner or when pernicious anemia is diagnosed with delay, these complications may be potentially life-threatening and sometimes irreversible. The current review aimed to focus on epidemiology, pathogenesis, and clinical presentations of pernicious anemia in an attempt to look beyond borders of medical specialties. It aimed to focus on micronutrient deficiencies besides the well-known vitamin B₁₂ deficiency, the diagnostic approach for pernicious anemia, its long-term complications and optimal clinical management, and endoscopic surveillance of patients with pernicious anemia.

The Effects of Vitamins and Micronutrients on Helicobacter pylori Pathogenicity, Survival, and Eradication: A Crosstalk between Micronutrients and Immune System

Helicobacter pylori as a class I carcinogen is correlated with a variety of severe gastroduodenal diseases; therefore, H. pylori eradication has become a priority to prevent gastric carcinogenesis. However, due to the emergence and spread of multidrug and single drug resistance mechanisms in H. pylori, as well as serious side effects of currently used antibiotic interventions, achieving successful H. pylori eradication has become exceedingly difficult. Recent studies expressed the intention of seeking novel strategies to improve H. pylori management and reduce the risk of H. pylori-associated intestinal and extragastrointestinal disorders. For which, vitamin supplementation has been demonstrated in many studies to have a tight interaction with H. pylori infection, either directly through the regulation of the host inflammatory pathways or indirectly by promoting the host immune response. On the other hand, H. pylori infection is reported to result in micronutrient malabsorption or deficiency. Furthermore, serum levels of particular micronutrients, especially vitamin D, are inversely correlated to the risk of H. pylori infection and eradication failure. Accordingly, vitamin supplementation might increase the efficiency of H. pylori eradication and reduce the risk of drug-related adverse effects. Therefore, this review aims at highlighting the regulatory role of micronutrients in H. pylori-induced host immune response and their potential capacity, as intrinsic antioxidants, for reducing oxidative stress and inflammation. We also discuss the uncovered mechanisms underlying the molecular and serological interactions between micronutrients and H. pylori infection to present a perspective for innovative in vitro investigations, as well as novel clinical implications.

Intracellular processing of vitamin B12 by MMACHC (CblC)

Vitamin B₁₂ (cobalamin, Cbl, B₁₂) is a water-soluble micronutrient synthesized exclusively by a group of microorganisms. Human beings are unable to make B₁₂ and thus obtain the vitamin via intake of animal products, fermented plant-based foods or supplements. Vitamin B₁₂ obtained from the diet comprises three major chemical forms, namely hydroxocobalamin (HOCbl), methylcobalamin (MeCbl) and adenosylcobalamin (AdoCbl). The most common form of B₁₂ present in supplements is cyanocobalamin (CNCbl). Yet, these chemical forms cannot be utilized directly as they come, but instead, they undergo chemical processing by the MMACHC protein, also known as CblC. Processing of dietary B₁₂ by CblC involves removal of the upper-axial ligand (beta-ligand) yielding the one-electron reduced intermediate cob(II)alamin. Newly formed cob(II)alamin undergoes trafficking and delivery to the two B₁₂-dependent enzymes, cytosolic methionine synthase (MS) and mitochondrial methylmalonyl-CoA mutase (MUT). The catalytic cycles of MS and MUT incorporate cob(II)alamin as a precursor to regenerate the coenzyme forms MeCbl and AdoCbl, respectively. Mutations and epimutations in the MMACHC gene result in cblC disease, the most common inborn error of B₁₂ metabolism, which manifests with combined homocystinuria and methylmalonic aciduria. Elevation of metabolites homocysteine and methylmalonic acid occurs because the lack of an active CblC blocks formation of the indispensable precursor cob(II)alamin that is necessary to activate MS and MUT. Thus, in patients with cblC disease, vitamin B₁₂ is absorbed and present in circulation in normal to high concentrations, yet, cells are unable to make use of it. Mutations in seemingly unrelated genes that modify MMACHC gene expression also result in clinical phenotypes that resemble cblC disease. We review current knowledge on structural and functional aspects of intracellular processing of vitamin B₁₂ by the versatile protein CblC, its partners and possible regulators.

Global, regional, and national consumption of animal-source foods between 1990 and 2018: findings from the Global Dietary Database

BACKGROUND

Diet is a major modifiable risk factor for human health and overall consumption patterns affect planetary health. We aimed to quantify global, regional, and national consumption levels of animal-source foods (ASF) to inform intervention, surveillance, and policy priorities.

METHODS

Individual-level dietary surveys across 185 countries conducted between 1990 and 2018 were identified, obtained, standardised, and assessed among children and adults, jointly stratified by age, sex, education level, and rural versus urban residence. We included 499 discrete surveys (91·2% nationally or subnationally representative) with data for ASF (unprocessed red meat, processed meat, eggs, seafood, milk, cheese, and yoghurt), comprising 3·8 million individuals from 134 countries representing 95·2% of the world population in 2018. We used Bayesian hierarchical models to account for differences in survey methods and representativeness, time trends, and input data and modelling uncertainty, with five-fold cross-validation.

FINDINGS

In 2018, mean global intake per person of unprocessed red meat was 51 g/day (95% uncertainty interval [UI] 48-54; region-specific range 7-114 g/day); 17 countries (23·9% of the world's population) had mean intakes of at least one serving (100 g) per day. Global mean intake of processed meat was 17 g/day (95% UI 15-21 g/day; region-specific range 3-54 g/day); seafood, 28 g/day (27-30 g/day; 12-44 g/day); eggs, 21 g/day (18-24 g/day; 6-35 g/day); milk 88 g/day (84-93 g/day; 45-185 g/day); cheese, 8 g/day (8-10 g/day; 1-34 g/day); and yoghurt, 20 g/day (17-23 g/day; 7-84 g/day). Mean national intakes were at least one serving per day for processed meat (≥50 g/day) in countries representing 6·9% of the global population; for cheese (≥42 g/day) in 2·3%; for eggs (≥55 g/day) in 0·7%; for milk (≥245 g/day) in 0·3%; for seafood (≥100 g/day) in 0·8%; and for yoghurt (≥245 g/day) in less than 0·1%. Among the 25 most populous countries in 2018, total ASF intake was highest in Russia (5·8 servings per day), Germany (3·8 servings per day), and the UK (3·7 servings per day), and lowest in Tanzania (0·9 servings per day) and India (0·7 servings per day). Global and regional intakes of ASF were generally similar by sex. Compared with children, adults generally consumed more unprocessed red meat, seafood and cheese, and less milk; energy-adjusted intakes of other ASF were more similar. Globally, ASF intakes (servings per week) were higher among more-educated versus less-educated adults, with greatest global differences for milk (0·79), eggs (0·47), unprocessed red meat (0·42), cheese (0·28), seafood (0·28), yoghurt (0·22), and processed meat (0·21). This was also true for urban compared to rural areas, with largest global differences (servings per week) for unprocessed red meat (0·47), milk (0·38), and eggs (0·20). Between 1990 and 2018, global intakes (servings per week) increased for unprocessed red meat (1·20), eggs (1·18), milk (0·63), processed meat (0·50), seafood (0·44), and cheese (0·14).

INTERPRETATION

Our estimates of ASF consumption identify populations with both lower and higher than optimal intakes. These estimates can inform the targeting of intervention, surveillance, and policy priorities relevant to both human and planetary health.

FUNDING

Bill & Melinda Gates Foundation and American Heart Association.

The role of vitamin B12 in viral infections: a comprehensive review of its relationship with the muscle-gut-brain axis and implications for SARS-CoV-2 infection

This comprehensive review establishes the role of vitamin B12 as adjunct therapy for viral infections in the treatment and persistent symptoms of COVID-19, focusing on symptoms related to the muscle-gut-brain axis. Vitamin B12 can help balance immune responses to better fight viral infections. Furthermore, data from randomized clinical trials and meta-analysis indicate that vitamin B12 in the forms of methylcobalamin and cyanocobalamin may increase serum vitamin B12 levels, and resulted in decreased serum methylmalonic acid and homocysteine concentrations, and decreased pain intensity, memory loss, and impaired concentration. Among studies, there is much variation in vitamin B12 doses, chemical forms, supplementation time, and administration routes. Larger randomized clinical trials of vitamin B12 supplementation and analysis of markers such as total vitamin B12, holotranscobalamin, total homocysteine and methylmalonic acid, total folic acid, and, if possible, polymorphisms and methylation of genes need to be conducted with people with and without COVID-19 or who have had COVID-19 to facilitate the proper vitamin B12 form to be administered in individual treatment.

Placing a Well-Designed Vegan Diet for Slovenes

Interest in vegan diets has increased globally as well as in Slovenia. The quantity of new scientific data requires a thorough synthesis of new findings and considerations about the current reserved position of the vegan diet in Slovenia. There is frequently confusion about the benefits of vegetarian diets that are often uncritically passed on to vegan diets and vice versa. This narrative review aims to serve as a framework for a well-designed vegan diet. We present advice on how to maximize the benefits and minimize the risks associated with the vegan diet and lifestyle. We highlight the proper terminology, present the health effects of a vegan diet and emphasize the nutrients of concern. In addition, we provide guidance for implementing a well-designed vegan diet in daily life. We conducted a PubMed search, up to November 2021, for studies on key nutrients (proteins, vitamin B12, vitamin D, omega-3 long chain polyunsaturated fatty acids (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)), calcium, iron, zinc, iodine and selenium) in vegan diets. Given the limited amount of scientific evidence, we focus primarily on the general adult population. A well-designed vegan diet that includes a wide variety of plant foods and supplementation of vitamin B12, vitamin D in the winter months and potentially EPA/DHA is safe and nutritionally adequate. It has the potential to maintain and/or to improve health. For physically active adult populations, athletes or individuals with fast-paced lifestyles, there is room for further appropriate supplementation of a conventional vegan diet according to individuals' health status, needs and goals without compromising their health. A healthy vegan lifestyle, as included in government guidelines for a healthy lifestyle, includes regular physical activity, avoidance of smoking, restriction of alcohol and appropriate sleep hygiene.

The effect of vitamin B12-supplementation on actigraphy measured sleep pattern; a randomized control trial

BACKGROUND

Vitamin B12 deficiency is common worldwide and has been associated with poor sleep. The effect of vitamin B12 supplementation on sleep in infants is not known.

AIMS

To measure the effect of daily supplementation of vitamin B12 for one year on sleep in infants at risk of deficiency.

METHODS

This was an individually randomized double-blind placebo-controlled trial in 600 infants in low-to middle-income neighborhoods in Bhaktapur, Nepal of daily supplementation of vitamin B12 for one year. Infants were included if they were 6-11 month year-old and with a length-for-age less than one z-score. Sleep was a predefined, secondary outcome, and was measured by actigraphy including sleep duration at night and total sleep duration (day and night), sleep onset latency (SOL), and wake after sleep onset (WASO). The effect of vitamin B12 on sleep was additionally assessed in predefined subgroups defined by stunting, underweight, vitamin B12 status, low birthweight, anemia and exclusive breastfeeding for 3 months.

RESULTS

There was no effect of vitamin B12 supplementation on sleep duration at night, total sleep duration, or WASO. There was a small significant negative effect for SOL. None of the included subgroup analyses revealed effect modification on any of the sleep outcomes.

CONCLUSION

Overall, vitamin B12 supplementation did not have an effect on sleep in infants or for high-risk subgroups, with the exception of a small negative effect for SOL. The present study does not support vitamin B12 supplementation to improve sleep in infants.

TRIAL REGISTRATION

clinicaltrials.gov: NCT02272842.

UNIVERSAL TRIAL NUMBER

U1111-1161-5187.

Homocysteine metabolism as the target for predictive medical approach, disease prevention, prognosis, and treatments tailored to the person

Homocysteine (Hcy) metabolism is crucial for regulating methionine availability, protein homeostasis, and DNA-methylation presenting, therefore, key pathways in post-genomic and epigenetic regulation mechanisms. Consequently, impaired Hcy metabolism leading to elevated concentrations of Hcy in the blood plasma (hyperhomocysteinemia) is linked to the overproduction of free radicals, induced oxidative stress, mitochondrial impairments, systemic inflammation and increased risks of eye disorders, coronary artery diseases, atherosclerosis, myocardial infarction, ischemic stroke, thrombotic events, cancer development and progression, osteoporosis, neurodegenerative disorders, pregnancy complications, delayed healing processes, and poor COVID-19 outcomes, among others. This review focuses on the homocysteine metabolism impairments relevant for various pathological conditions. Innovative strategies in the framework of 3P medicine consider Hcy metabolic pathways as the specific target for in vitro diagnostics, predictive medical approaches, cost-effective preventive measures, and optimized treatments tailored to the individualized patient profiles in primary, secondary, and tertiary care.

The Potential Role of Vitamin B12 in the Prevention of COVID-19 Complications: A Narrative Review

The elderly are more prone to mortality from COVID-19 infection, as they are susceptible to develop acute respiratory distress syndrome (ARDS). For COVID-19 patients with ARDS caused by sepsis or septic shock, high-dose parenteral vitamin B12 appears to be a potential new treatment option. Vitamin B12 may play a substantial impact in COVID-19 morbidity and mortality reduction owing to its function in DNA synthesis, cellular control, improvement of anti-inflammatory immune responses, and decrease of pro-inflammatory responses. This review aims to assess the functional role of Vitamin B12 in COVID-19 in terms of its immunomodulatory effect, role in cellular and humoral immunity and maintaining the gut microbe homeostasis. From data inception to June 2021, accessible electronic databases were searched for research/review articles reporting on the function of Vitamin B12 in COVID-19. Scopus, Web of Science, PubMed, WHO worldwide research on COVID-19 and the clinical trials registration “https://clinicaltrials.gov/” were used to conduct the systematic search by using keywords: “COVID-19 and “Vitamin B12”. Also, based on these outcomes, it can be concluded that Vitamin B12 may have a potential role in preventing COVID-19 complications. Further, studies evaluating the role of Vitamin B12 in COVID-19 may open a new array of ideas on the optimal and the well-tolerated dose and timing of its administration in COVID-19 patients.

Micronutrients May Be a Unique Weapon Against the Neurotoxic Triad of Excitotoxicity, Oxidative Stress and Neuroinflammation: A Perspective

Excitotoxicity has been implicated in many neurological disorders and is a leading cause of oxidative stress and neuroinflammation in the nervous system. Most of the research to date has focused on each of these conditions individually; however, excitotoxicity, oxidative stress, and neuroinflammation have the ability to influence one another in a self-sustaining manner, thus functioning as a "neurotoxic triad." This perspective article re-introduces the concept of the neurotoxic triad and reviews how specific dietary micronutrients have been shown to protect against not only oxidative stress, but also excitotoxicity and neuroinflammation. Future dietary interventions for neurological disorders could focus on the effects on all three aspects of the neurotoxic triad.

Improvement in vitamin B12 status of Wistar rats by supplementing the diet with Chlorella vulgaris biomass

The sources of bioavailable vitamin B₁₂ are limited, and most of them are animal-derived. Chlorella vulgaris, a freshwater microalga, is known for immune system boosting, nutraceutical properties and presence of a natural form of vitamin B₁₂. The present study focused on the in vivo evaluation of the Chlorella biomass as a source of bioavailable vitamin B₁₂ to alleviate the vitamin B₁₂ deficiency status of Wistar rats. Experimental animals were evaluated for the vitamin B₁₂ deficiency-related circulatory marker (serum vitamin B₁₂) and functional markers (plasma homocysteine and urinary methylmalonic acid), haematological and histological changes. The results showed that an increase of 2.4-fold in urinary methylmalonic acid (13.01 ± 0.89 µmoles moles of creatinine^-1), 2.6-fold in plasma homocysteine (17.18 ± 3.57 µmole L^-1), and 48% decrease in serum vitamin B₁₂ levels (252.69 ± 1.46 pg mL^-1) in vitamin B₁₂ deficient group compared to control animals. The Chlorella biomass supplementation in the diet led to the restoration of the functional and circulatory markers, hematological parameters, and vitamin B₁₂ content of kidney and liver to control levels. The Chlorella biomass supplementation increased the erythrocyte precursors and MAST cells in the bone marrow and also normalized the histological features of kidney, liver, and lung tissues. The results suggest that the vitamin B₁₂ from the Chlorella biomass was bioavailable and facilitated the improvement of vitamin B₁₂ status in deficient rats.

Severe Vitamin B12 Deficiency Mimicking Microangiopathic Hemolytic Anemia

Most individuals with vitamin B12 deficiency present with anemia, fatigue, and neurologic disturbances such as paresthesia and loss of sensory function if chronic. However, in severe states, it may manifest as hemolytic anemia, thrombocytopenia, schistocytosis, elevated lactate dehydrogenase, and low reticulocyte production. This phenomenon is known as pseudo-thrombotic microangiopathy (TMA), and is most commonly due to pernicious anemia. The overlap in clinical presentation with primary TMA creates a challenge in the diagnosis and management of pseudo-TMA. Primary TMA, particularly thrombotic thrombocytopenic purpura, is emergently managed with plasma exchange and may require admission to an intensive care unit due to high risk of mortality. In contrast, pseudo-TMA does not respond to plasma exchange and instead is treated with vitamin B12 supplementation. Patients with this atypical presentation of B12 deficiency may receive unnecessary, costly, and potentially harmful therapy. We present the case of a patient with pseudo-TMA in the setting of pernicious anemia.