Cobalamin related parameters and disease patterns in patients with increased serum cobalamin levels

Macro-B12 and Unexpectedly High Levels of Plasma B12: A Critical Review

A low total plasma vitamin B12 supports a clinical suspicion of B12 deficiency, while the interpretation of an unexpectedly normal/high level is marred by controversies. Here, we critically review current knowledge on B12 in blood plasma, including the presence of the so-called "macro-B12". The latter form is most often defined as the fraction of B12 that can be removed by precipitation with polyethylene glycol (PEG), a nonspecific procedure that also removes protein polymers and antibody-bound analytes. Plasma B12 includes B12 attached to transcobalamin and haptocorrin, and an increased concentration of one or both proteins almost always causes an elevation of B12. The total plasma B12 is measured by automated competitive binding assays, often incorrectly referred to as immunoassays, since the binding protein is intrinsic factor and not an antibody. An unexpectedly high level of B12 may be further explored using immunological measurements of haptocorrin and transcobalamin (optionally combined with e.g., size-exclusion chromatography). Nonspecific methods, such as PEG precipitation, are likely to give misleading results and cannot be recommended. Currently, the need for evaluation of a high B12 of unknown etiology is limited since other tests (such as measurements of methylmalonic acid) may better guide the diagnosis of B12 deficiency.

Incidental detection of raised serum levels of vitamin B12 and its association with neoplasms

BACKGROUND AND OBJECTIVES

Elevated serum levels of vitamin B12 have been associated with oncohematological diseases. However, the relevance of its incidental detection in subjects without a previous diagnosis of cancer is unknown. The aim of this study was to evaluate the relationship between incidental hypercobalaminemia (vitamin B12 > 1000 pg/mL) and the diagnosis of a tumor process in patients without a diagnosis and to establish the risk factors.

MATERIAL AND METHODS

Retrospective observational study of a cohort of patients with hypercobalaminemia. The incidence of neoplasms was compared with a cohort of patients with vitamin B12 levels <1000 pg/mL.

RESULTS

Vitamin B12 determinations of 4800 subjects were selected. Of them, 345 (7.1%) had levels >1000 pg/mL. 68 (28.4%) were excluded due to exogenous administration, 12 (5%) due to insufficient data and 15 (3%) due to having an active neoplasia, selecting 250 patients, with a median follow-up of 22 (IQR 12-39) months. Structural liver disease was detected in 59 (23.6%). 18.2% (44 patients) had solid organ cancer and 17 (7.1%) had malignant hemopathy. The average time from the detection of hypercobalaminemia to the diagnosis of cancer was about 10 months. The median until the diagnosis of neoplasia was higher in the high vitamin B12 group (13 vs. 51 months p < 0.001). Hypercobalaminemia (HR 11.8; 95% CI 2.8-49.6; p = 0.001) and smoking (HR 4.0; 95% CI, 2.15-7.59; p < 0.001) were independent predictors of neoplasia in the multivariate analysis.

CONCLUSIONS

Incidental detection of serum vitamin B12 levels >1000 pg/mL is high in the population. The diagnosis of solid organ and hematological neoplasia is frequent during the following year of follow-up, with hypercobalaminemia and smoking being predictors of a higher risk of cancer.

B Vitamins, Glucoronolactone and the Immune System: Bioavailability, Doses and Efficiency

The present review deals with two main ingredients of energy/power drinks: B vitamins and glucuronolactone and their possible effect on the immune system. There is a strong relationship between the recommended daily dose of selected B vitamins and a functional immune system. Regarding specific B vitamins: (1) Riboflavin is necessary for the optimization of reactive oxygen species (ROS) in the fight against bacterial infections caused by Staphylococcus aureus and Listeria monocytogenes. (2) Niacin administered within normal doses to obese rats can change the phenotype of skeletal fibers, and thereby affect muscle metabolism. This metabolic phenotype induced by niacin treatment is also confirmed by stimulation of the expression of genes involved in the metabolism of free fatty acids (FFAs) and oxidative phosphorylation at this level. (3) Vitamin B5 effects depend primarily on the dose, thus large doses can cause diarrhea or functional disorders of the digestive tract whereas normal levels are effective in wound healing, liver detoxification, and joint health support. (4) High vitamin B6 concentrations (>2000 mg per day) have been shown to exert a significant negative impact on the dorsal root ganglia. Whereas, at doses of approximately 70 ng/mL, sensory symptoms were reported in 80% of cases. (5) Chronic increases in vitamin B12 have been associated with the increased incidence of solid cancers. Additionally, glucuronolactone, whose effects are not well known, represents a controversial compound. (6) Supplementing with D-glucarates, such as glucuronolactone, may help the body's natural defense system function better to inhibit different tumor promoters and carcinogens and their consequences. Cumulatively, the present review aims to evaluate the relationship between the selected B vitamins group, glucuronolactone, and the immune system and their associations to bioavailability, doses, and efficiency.

Association between Elevated Plasma Vitamin B12 and Short-Term Mortality in Elderly Patients Hospitalized in an Internal Medicine Unit

Background

The prognostic value of vitamin B12 blood levels remains controversial. An association between elevated vitamin B12 and mortality has been reported, particularly among elderly patients with cancers and liver or blood diseases. The present study explored the relationship between mortality and elevated vitamin B12 levels in a population of unscheduled inpatients in an internal medicine unit.

Methods

This retrospective observational analysis was conducted between August 2014 and December 2018. We compared 165 patients with elevated plasma vitamin B12 levels (>600 pmol/l) with a random sample of 165 patients with normal B12 levels who were hospitalized during the same period. Demographic, clinical, and biological characteristics were assessed during hospitalization. The primary endpoint was all-cause death at 1 year.

Results

Patients with elevated B12 were younger, with a lower body mass index and lower plasma albumin than those with normal B12 (75 ± 16 years vs 79 ± 13 years, p = 0.047; 23 ± 5 vs 26 ± 7 kg/m2, p  <  0.001; and 33 ± 5 vs 35 ± 5 g/l, p  <  0.001, respectively). The prevalence of auto-immune disease and referral from an intensive care unit was higher among patients with elevated B12 (11% vs 5%, p = 0.043 and 36% vs 10%, p  <  0.001, respectively). After 1 year of follow-up, 64 (39%) patients with elevated B12 had died compared to 43 (26%) patients with normal B12 (p = 0.018). Multivariate analysis using the Cox proportional hazards regression model adjusted for age, gender, body mass index, intensive care unit hospitalization, albumin level, and the presence of solid cancer or autoimmune disease revealed elevated B12 to be associated with a significant risk of death in the first year of follow-up (hazard ratio: 1.71 [1.08-2.7], p = 0.022).

Conclusion

Elevated B12 is an early warning indicator of increased short-term mortality, such as independently of age, cancer, or comorbidities, in patients hospitalized in an internal medicine department.

The Impact of Clinical Factors, Vitamin B12 and Total Cholesterol on Severity of Anorexia Nervosa: A Multicentric Cross-Sectional Study

Severe forms of Anorexia Nervosa (AN) are characterized by medical complications, psychiatric comorbidity, and high mortality. This study investigated potential associations between clinical/biological factors and the severity of AN, measured by the Body Mass Index (BMI). Red and white blood cells, hemoglobin, platelets, iron, vitamins D and B12, folate, and total cholesterol were measured in a mixed sample of 78 inpatients and outpatients. Linear regressions and one-way analyses of variance (ANOVAs) were carried out to evaluate the relationship between BMI and clinical/biochemical variables. BMI was significantly lower in hospitalized patients (F = 4.662; p = 0.034) and in those under pharmacological treatment (F = 5.733; p = 0.019) or poly-therapy (F = 5.635; p = 0.021). Higher vitamin B12 (β = -0.556, p < 0.001), total cholesterol (β = -0.320, p = 0.027), and later age at onset (with a trend towards significance) (β = -0.376, p = 0.058) were associated with a lower BMI. Increased total cholesterol and vitamin B12, later age at onset, current pharmacological treatment, and poly-therapy might be distinctive in patients with a lower BMI. In clinical practice, these findings may contribute to the early identification of AN patients at higher risk of developing complicated or chronic forms of the disorder. Further studies on larger samples are needed to identify potential predictive factors of AN severity in the framework of precision medicine.

Exosomal MicroRNA-223, MicroRNA-146, and MicroRNA-21 Profiles and Biochemical Changes in Laryngeal Cancer

Laryngeal squamous cell carcinoma (LSCC) is one of the most aggressive cancers, and its early diagnosis is urgent. Exosomes are believed to have diagnostic significance in cancer. However, the role of serum exosomal microRNAs, miR-223, miR-146, and miR-21, and phosphatase and tensin homologue (PTEN) and hemoglobin subunit delta (HBD) mRNAs in LSCC is unclear. Exosomes were isolated from the blood serum of 10 LSCC patients and 10 healthy controls to perform scanning electron microscopy and liquid chromatography quadrupole time-of-flight mass spectrometry analyses to characterize them and to undergo reverse transcription polymerase chain reaction to identify miR-223, miR-146, miR-21, and PTEN and HBD mRNA expression phenotypes. Biochemical parameters, including serum C-reactive protein (CRP) and vitamin B12, were also obtained. Serum exosomes of 10-140 nm were isolated from LSCC and controls. Serum exosomal miR-223, miR-146, and PTEN were found to be significantly decreased (p < 0.05), in contrast to serum exosomal miRNA-21 (p < 0.01), and serum vitamin B12 and CRP (p < 0.05) were found to be significantly increased, in LSCC vs controls. Our novel data show that the combination of reduced serum exosomal miR-223, miR-146, and miR-21 profiles and biochemical alterations in CRP and vitamin B12 levels may be useful indicators of LSCC that could be validated by large studies. Our findings also suggest a possible negative regulatory effect of miR-21 on PTEN in LSCC, encouraging a more extensive investigation of its role.

Relationship between high dose intake of vitamin B12 and glaucoma: Evidence from NHANES 2005-2008 among United States adults

Objective

Glaucoma has currently become the second leading cause of blindness in the world. Serum vitamin B12 level has been found to be involved in the development and progression of glaucoma. We performed the present study to confirm this association.

Methods

This cross-sectional study included 594 participants aged 40 years and older in the National Health and Nutrition Examination Survey (NHANES) from 2005 to 2008. Retinal imaging was performed using the Ophthalmic Digital Imaging system (Retinography) to assess the retina for the presence of features of glaucomatous lesions. Logistic regression models were used to assess the association between dietary vitamin intake and glaucoma.

Results

After screening, 594 subjects were finally included. Among all vitamin intakes, we observed significant differences between the two groups for vitamin B12 intake (5.93 vs. 4.77 mg, p = 0.033). According to the logistic regression results, the intake of vitamin B12 was significantly positively associated with glaucoma (model 1: OR = 1.078, 95% CI = 1.019-1.141; model 2: OR = 1.092, 95% CI = 1.031-1.158; model 3: OR = 1.092, 95% CI = 1.029-1.158). After performing a quantile regression, we observed a significant positive association between vitamin B12 intake and incident glaucoma in the fourth quartile (model 1: OR = 1.133, 95% CI = 1.060-1.210; model 2: OR = 1.141, 95% CI = 1.072-1.215; model 3: OR = 1.146, 95% CI = 1.071-1.226).

Conclusions

Therefore, the above results, high-dose intake of vitamin B12 may promote the development of glaucoma.

Vitamin B12 in Leber hereditary optic neuropathy mutation carriers: a prospective cohort study

Background

Leber hereditary optic neuropathy (LHON) is the most common mitochondrial disorder, frequently resulting in acute or subacute severe bilateral central vision loss. Vitamin B12 deficiency is also a known cause of optic neuropathy through mitochondrial dysfunction. Here we evaluated the prevalence and clinical significance of vitamin B12 deficiency in a large cohort of LHON patients and asymptomatic mutation carriers from a tertiary referral center.

Methods

From the Munich LHON prospective cohort study, participants included all LHON patients and asymptomatic LHON mutation carriers, who were recruited between February 2014 and March 2020 and consented to participate. Neurological, general, and ophthalmological examinations were regularly performed, as were laboratory tests. Vitamin B12 deficiency was diagnosed if serum vitamin B12 was below 201 pg/mL, or if 201–339 pg/mL plus low serum holotranscobalamin or elevated serum methylmalonic acid or elevated total plasma homocysteine.

Results

We analyzed 244 subjects, including 147 symptomatic LHON patients (74% males) and 97 asymptomatic mutation carriers (31% males). Median age at study baseline was 34 years (range 5–82 years). The prevalence of vitamin B12 deficiency was higher for LHON mutation carriers than for the general population in all age categories. This was statistically significant for the LHON mutation carriers under 65 years (21% vs. 5–7%, p = 0.002). While vitamin B12 deficiency prevalence was not statistically different between LHON patients and asymptomatic mutation carriers, its clinical correlates, e.g., macrocytosis and polyneuropathy, were more frequent in the subgroup of LHON patients. Excessive alcohol consumption was a significant predictor of vitamin B12 deficiency (p < 0.05).

Conclusions

The high prevalence of vitamin B12 deficiency in LHON mutation carriers, both asymptomatic mutation carriers and LHON patients, highlights the need for regular vitamin B12 screening in this population, in order to ensure early treatment, aiming for better outcomes. Our study is not conclusive regarding vitamin B12 deficiency as determinant for disease conversion in LHON, and further research is warranted to disentangle the role of vitamin B12 in the pathophysiology and prognosis of LHON.

Liver and vitamin B12 parameters in patients with anorexia nervosa before and after short-term weight restoration

Hepatic involvement in anorexia nervosa (AN) has been previously reported, but a link to elevated vitamin B₁₂ concentrations, which can be a sign for liver damage, has not been thoroughly examined. We measured liver enzymes (alanine aminotransferase, aspartate aminotransferase, gamma-glutamyltransferase) and vitamin B₁₂ parameters (total B₁₂, holotranscobalamin, methylmalonic acid) in the plasma of young female patients with acute AN (n=77) and after short-term weight restoration (n=58, median body mass increase=25%), in comparison to healthy control participants (n=63). For a comprehensive assessment of vitamin B₁₂ status, the combined marker cB₁₂ was calculated. In acute AN, activities of alanine aminotransferase and gamma-glutamyltransferase as well as holotranscobalamin concentrations were elevated, and alanine aminotransferase activities positively correlated with total B₁₂, holotranscobalamin and cB₁₂ in patients with elevated liver enzyme activities. After weight restoration, alanine aminotransferase activities and holotranscobalamin concentrations were elevated, and cB₁₂ increased above the level of the healthy control group. The present study provides further evidence for a hepatic involvement in acute AN in concert with vitamin B₁₂ parameters and points to refeeding-associated alterations of liver and vitamin B₁₂ parameters. Future studies should include non-invasive methods to characterize hepatic involvement and evaluate vitamin B₁₂ status as a potential marker of liver damage/irritation.

Diagnostic and Therapeutic Perspectives Associated to Cobalamin-Dependent Metabolism and Transcobalamins’ Synthesis in Solid Cancers

Cobalamin or vitamin B12 (B12) is a cofactor for methionine synthase and methylmalonyl-CoA mutase, two enzymes implicated in key pathways for cell proliferation: methylation, purine synthesis, succinylation and ATP production. Ensuring these functions in cancer cells therefore requires important cobalamin needs and its uptake through the transcobalamin II receptor (TCII-R). Thus, both the TCII-R and the cobalamin-dependent metabolic pathways constitute promising therapeutic targets to inhibit cancer development. However, the link between cobalamin and solid cancers is not limited to cellular metabolism, as it also involves the circulating transcobalamins I and II (TCI or haptocorrin and TCII) carrier proteins, encoded by TCN1 and TCN2, respectively. In this respect, elevations of B12, TCI and TCII concentrations in plasma are associated with cancer onset and relapse, and with the presence of metastases and worse prognosis. In addition, TCN1 and TCN2 overexpressions are associated with chemoresistance and a proliferative phenotype, respectively. Here we review the involvement of cobalamin and transcobalamins in cancer diagnosis and prognosis, and as potential therapeutic targets. We further detail the relationship between cobalamin-dependent metabolic pathways in cancer cells and the transcobalamins’ abundancies in plasma and tumors, to ultimately hypothesize screening and therapeutic strategies linking these aspects.

"Macro transcobalamin causing raised vitamin B12: Case-based laboratory investigation"

Determination of plasma vitamin B12 (B12) is a frequently requested laboratory analysis, mainly employed to establish B12 deficiency. However, an increased level of B12 is a common unexpected finding that may be related to an increased concentration of one of the B12 binding proteins, haptocorrin or transcobalamin. This paper describes the extensive laboratory evaluation of a patient with an elevated level of plasma B12 with various well-established assays. Initial studies suggested the presence of a macromolecule consisting of haptocorrin bound B12. Specific determinations of the B12-binding proteins revealed normal amounts of haptocorrin but a markedly increase in both total and B12 saturated transcobalamin (holo-TC). The results are in accord with the presence of macro-transcobalamin. These experiments reveal that determination of the nature of the B12-macromolecules is troublesome due to differences in assays applied to measure these proteins. In addition, this publication creates awareness of macro-holo-TC as a cause of an unexplained increased B12 level.

Persistent elevation of plasma vitamin B12 is strongly associated with solid cancer

Elevated plasma vitamin B12 has been associated with solid cancers, based on a single B12 measurement. We evaluated the incidence of solid cancers following B12 measurement in patients with persistent elevated B12, compared to patients without elevated B12 and to patients with non-persistent elevated B12. The study population included patients with at least two plasma B12 measurements without already known elevated-B12-related causes. Patients with elevated plasma B12 (≥ 1000 ng/L) at first measurement (n = 344) were matched for age and sex with patients having 2 normal B12 measurements (< 1000 ng/L) (NN group, n = 344). The patients with elevated plasma B12 at first measurement were split into 2 groups, according to the presence (EE group, n = 144) or the absence (EN group, n = 200) of persistent elevated plasma B12 at second measurement. We compared the cancer-free survival during 60 months between the groups after adjustment for the other elevated-B12-related causes in a survival competing risk model. Compared to the NN group, a persistent elevated plasma B12 ≥ 1000 ng/mL was strongly associated with the occurrence of solid cancer (HR 5.90 [95% CI 2.79-12.45], p < 0.001), contrary to non-persistent plasma B12 elevation (p = 0.29). These results could help to select patients in whom the screening for solid cancers would be of interest.

Diseases associated with hypercobalaminemia in dogs in United Kingdom: A retrospective study of 47 dogs

Cobalamin concentration is often assessed in clinical practice but little is known about the significance of hypercobalaminemia. The objective of this retrospective study was to identify the conditions associated with hypercobalaminemia in dogs and to investigate association with clinicopathological variables. Medical records of dogs having serum cobalamin measured between 2016 and 2018 were reviewed. One hundred sixty dogs were included and 47 (29%) showed hypercobalaminemia. Dogs with hypercobalaminemia had gastrointestinal (57%), hepatic (11%), neurological (11%), endocrine (9%), renal (4%), pancreatic (2%), and miscellaneous (6%) diseases. Overall, 11% had neoplasia. This distribution was not significantly different from that for hypocobalaminemic and normocobalaminemic dogs. There were significantly more dogs with hyperfolatemia in the hypercobalaminemia group. These results suggest that in clinical practice hypercobalaminemia is commonly identified in gastrointestinal and hepatic disease in dogs, but can also be seen with endocrine and neurological conditions. The frequency of hyperfolatemia alongside hypercobalaminemia may reflect common metabolic pathways.

Ethnicity influences total serum vitamin B12 concentration: a study of Black, Asian and White patients in a primary care setting

AIMS

A growing body of evidence suggests that ethnicity and race influence vitamin B₁₂ metabolism and status yet clinical awareness of this is poor, causing doubts regarding diagnosis and treatment. Moreover, deficiency and insufficiency cut-offs are universally applied for this test in most diagnostic settings. The objective of this study was to assess serum vitamin B₁₂ concentrations in Black, Asian and White primary care patients in London, UK, particularly in patients of Black or Black British ethnic origin and establish if there is a need for specific reference ranges.

METHODS

Serum B₁₂ results from 49 414 patients were processed between January 2018 and November 2019 using the Architect assay (Abbott Diagnostics) at St. Thomas' Hospital, London, UK. Age, sex and ethnicity data were collected from the laboratory Health Informatics Team.

RESULTS

Black patients (n=13 806) were found to have significantly higher serum vitamin B₁₂ concentration across all age groups and both sexes, especially Nigerian patients (median B₁₂ 505 pmol/L,IQR: 362-727, n=891), compared with Asian and White ethnic groups (p<0.001). Binary logistic regression analysis revealed that the Black or Black British ethnic group had the strongest association with elevated serum B₁₂ (>652 pmol/L) (adjusted OR 3.38, 95% CI 3.17 to 3.61, p<0.0001).

CONCLUSIONS

It is likely that a combination of genetic and acquired/environmental factors are responsible for the ethnic differences in serum B₁₂. This suggests that there is a need for ethnic-specific reference ranges with indications for the incorporation of age and sex too.

Plasma Vitamin B12 Levels, High-Dose Vitamin B12 Treatment, and Risk of Dementia

Background:

It is controversial whether B12 deficiency causes dementia or B12 treatment can prevent dementia.

Objective:

To assess associations between low plasma (P-)B12 levels, B12 treatment, and risk of Alzheimer’s disease (AD; primary outcome) and all-cause or vascular dementia (secondary outcomes).

Methods:

We conducted a population-based cohort study using Danish registry data to assess associations between low P-B12 levels, high-dose injection or oral B12 treatment, and risk of dementia (study period 2000–2013). The primary P-B12 cohort included patients with a first-time P-B12 measurement whose subsequent B12 treatment was recorded. The secondary B12 treatment cohort included patients with a first-time B12 prescription and P-B12 measurement within one year before this prescription. For both cohorts, patients with low P-B12 levels (<200 pmol/L) were propensity score-matched 1:1 with patients with normal levels (200–600 pmol/L). We used multivariable Cox regression to compute 0–15-year hazard ratios for dementia.

Results:

For low P-B12 and normal P-B12 level groups, we included 53,089 patients in the primary P-B12 cohort and 13,656 patients in the secondary B12 treatment cohort. In the P-B12 cohort, hazard ratios for AD centered around one, regardless of follow-up period or treatment during follow-up. In the B12 treatment cohort, risk of AD was unaffected by low pre-treatment P-B12 levels, follow-up period and type of B12 treatment. Findings were similar for all-cause and vascular dementia.

Conclusion:

We found no associatio1n between low P-B12 levels and dementia. Associations were unaffected by B12 treatment. Results do not support routine screening for B12 deficiency in patients with suspected dementia.

Evolution of plasma vitamin B12 in patients with solid cancers during curative versus supportive care

INTRODUCTION

The direction of the causal link between solid cancers and elevated plasma vitamin B₁₂ (B₁₂) remains uncertain.

METHODS

We retrospectively included patients having two B₁₂ measurements with a B₁₂ initially ≥ 1000 ng/l and a solid cancer diagnosed between the measurements. Patients were included in the Curative or Supportive group according to their treatments.

RESULTS

B₁₂ changes over time differed between groups (p = 0.001): +157.4 ng/l/month in the Supportive care group versus -171.6 ng/l/month in the Curative care group.

CONCLUSIONS

The decrease of plasma B₁₂ in cases of curative care could suggest that this B₁₂ elevation is secondary to solid cancers.

B Vitamins and One-Carbon Metabolism: Implications in Human Health and Disease

Vitamins B9 (folate) and B12 are essential water-soluble vitamins that play a crucial role in the maintenance of one-carbon metabolism: a set of interconnected biochemical pathways driven by folate and methionine to generate methyl groups for use in DNA synthesis, amino acid homeostasis, antioxidant generation, and epigenetic regulation. Dietary deficiencies in B9 and B12, or genetic polymorphisms that influence the activity of enzymes involved in the folate or methionine cycles, are known to cause developmental defects, impair cognitive function, or block normal blood production. Nutritional deficiencies have historically been treated with dietary supplementation or high-dose parenteral administration that can reverse symptoms in the majority of cases. Elevated levels of these vitamins have more recently been shown to correlate with immune dysfunction, cancer, and increased mortality. Therapies that specifically target one-carbon metabolism are therefore currently being explored for the treatment of immune disorders and cancer. In this review, we will highlight recent studies aimed at elucidating the role of folate, B12, and methionine in one-carbon metabolism during normal cellular processes and in the context of disease progression.

Elevated Plasma Vitamin B12 in Patients with Hepatic Glycogen Storage Diseases

Background: Hepatic glycogen storage diseases (GSDs) are inborn errors of metabolism affecting the synthesis or breakdown of glycogen in the liver. This study, for the first time, systematically assessed vitamin B₁₂ status in a large cohort of hepatic GSD patients. Methods: Plasma vitamin B₁₂, total plasma homocysteine (tHcy) and methylmalonic acid concentrations were measured in 44 patients with hepatic GSDs and compared to 42 healthy age- and gender-matched controls. Correlations of vitamin B₁₂ status with different disease markers of GSDs (including liver transaminase activities and triglycerides) as well as the vitamin B₁₂ intake were studied. Results: GSD patients had significantly higher plasma vitamin B₁₂ concentrations than healthy controls (p = 0.0002). Plasma vitamin B₁₂ concentration remained elevated in GSD patients irrespective of vitamin B₁₂ intake. Plasma vitamin B₁₂ concentrations correlated negatively with triglyceride levels, whereas no correlations were detected with liver transaminase activities (GOT and GPT) in GSD patients. Merging biomarker data of healthy controls and GSD patients showed a positive correlation between vitamin B₁₂ status and liver function, which suggests complex biomarker associations. A combined analysis of biomarkers permitted a reliable clustering of healthy controls versus GSD patients. Conclusions: Elevated plasma concentration of vitamin B₁₂ (irrespective of B₁₂ intake) is a common finding in patients with hepatic GSD. The negative correlation of plasma vitamin B₁₂ with triglyceride levels suggests an influence of metabolic control on the vitamin B₁₂ status of GSD patients. Elevated vitamin B₁₂ was not correlated with GOT and GPT in our cohort of GSD patients. Merging of data from healthy controls and GSD patients yielded positive correlations between these biomarkers. This apparent dichotomy highlights the intrinsic complexity of biomarker associations and argues against generalizations of liver disease and elevated vitamin B₁₂ in blood. Further studies are needed to determine whether the identified associations are causal or coincidental, and the possible impact of chronically elevated vitamin B₁₂ on GSD.

Plasma concentrations of vitamin B12 and folate and global cognitive function in an older population: cross-sectional findings from The Irish Longitudinal Study on Ageing (TILDA)

The uncertainty surrounding high intakes of folic acid and associations with cognitive decline in older adults with low vitamin B12 status has been an obstacle to mandatory folic acid fortification for many years. We estimated the prevalence of combinations of low/normal/high vitamin B12 and folate status and compared associations with global cognitive function using two approaches, of individuals in a population-based study of those aged ≥50 years in the Republic of Ireland. Cross-sectional data from 3781 men and women from Wave 1 of The Irish Longitudinal Study on Ageing were analysed. Global cognitive function was assessed by the Mini Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA). Prevalence estimates for combinations of vitamin B12 (plasma vitamin B12 < or ≥258 pmol/l) and folate (plasma folate ≤ or >45·3 nmol/l) concentrations were generated. Negative binomial regression models were used to investigate the associations of vitamin B12 and folate status with global cognitive function. Of the participants, 1·5 % (n 51) had low vitamin B12 (<258 pmol/l) and high folate (>45·3 nmol/l) status. Global cognitive performance was not significantly reduced in these individuals when compared with those with normal status for both B-vitamins (n 2433). Those with normal vitamin B12/high folate status (7·6 %) had better cognitive performance (MMSE: incidence rate ratio (IRR) 0·82, 95 % CI 0·68, 0·99; P = 0·043, MoCA: IRR 0·89, 95 % CI 0·80, 0·99; P = 0·025). We demonstrated that high folate status was not associated with lower cognitive scores in older adults with low vitamin B12 status. These findings provide important safety information that could guide fortification policy recommendations in Europe.

Higher vitamin B12 levels in neurodevelopmental disorders than in healthy controls and schizophrenia: A comparison among participants between 2 and 53 years

Recent studies suggest that both high and low levels of vitamin B12 (vitB12) may have negative health impacts. We measured VitB12 in patients with the Neurodevelopmental disorders (ND) (n = 222), comprised of Autism Spectrum Disorders, specific Developmental disorders, and Intellectual Disability (aged 2-53 years), schizophrenia (n = 401), and healthy controls (HC) (n = 483). Age-and gender-adjusted vitB12 z-scores were calculated by comparisons with a reference population (n = 76 148). We found higher vitB12 in ND (median 420 pmol/L, mean z-score: 0.30) than in HC (316 pmol/L, z-score: 0.06, P < .01) and schizophrenia (306 pmol/L, z-score: -0.02, P < .001), which was significant after adjusting for age, gender, vitB12 supplement, folate, hemoglobin, leukocytes, liver, and kidney function (P < .02). In ND, 20% (n = 44) had vitB12 above 650 pmol/L, and 1% (n = 3) had below 150 pmol/L (common reference limits). In 6.3% (n = 14) of ND, vitB12 was above 2SD of mean in the age-and gender-adjusted reference population, which was more frequent than in HC (n = 8, 1.6%), OR: 4.0, P = .001. Low vitB12 was equally frequent as in HC, and vitB12 z-scores were equal across the age groups. To conclude, vitB12 was higher in ND than in HC and schizophrenia, suggesting a specific feature of ND, which warrants further studies to investigate the underlying mechanisms.

Vitamin B12 measurements across neurodegenerative disorders

Background

Vitamin B12 deficiency causes a number of neurological features including cognitive and psychiatric disturbances, gait instability, neuropathy, and autonomic dysfunction. Clinical recognition of B12 deficiency in neurodegenerative disorders is more challenging because it causes defects that overlap with expected disease progression. We sought to determine whether B12 levels at the time of diagnosis in patients with Parkinson’s disease (PD) differed from those in patients with other neurodegenerative disorders.

Methods

We performed a cross-sectional analysis of B12 levels obtained around the time of diagnosis in patients with PD, Multiple System Atrophy (MSA), Dementia with Lewy Bodies (DLB), Alzheimer’s disease (AD), Progressive Supranuclear Palsy (PSP), Frontotemporal Dementia (FTD), or Mild Cognitive Impairment (MCI). We also evaluated the rate of B12 decline in PD, AD, and MCI.

Results

In multivariable analysis adjusted for age, sex, and B12 supplementation, we found that B12 levels were significantly lower at time of diagnosis in patients with PD than in patients with PSP, FTD, and DLB. In PD, AD, and MCI, the rate of B12 decline ranged from − 17 to − 47 pg/ml/year, much greater than that reported for the elderly population.

Conclusions

Further studies are needed to determine whether comorbid B12 deficiency affects progression of these disorders.

Strength of the Association of Elevated Vitamin B12 and Solid Cancers: An Adjusted Case-Control Study

The association between elevated plasma vitamin B12 (B12) level and solid cancers has been documented by two national registries. However, their design did not allow for the adjustment for other conditions associated with elevated B12. The objectives of this study were to confirm this association after the adjustment for all causes of elevated B12, and to study the variations according to the increasing B12 level, the type of cancers, and the presence of metastases. We compared 785 patients with B12 ≥ 1000 ng/L with 785 controls matched for sex and age with B12 < 1000 ng/L. Analyses were adjusted for the causes of elevated B12: myeloid blood malignancies, acute or chronic liver diseases, chronic kidney failure, autoimmune or inflammatory diseases, and excessive B12 supplementation. A B12 ≥ 1000 ng/L was associated with the presence of solid cancer without metastases (OR 1.96 [95%CI: 1.18 to 3.25]) and with metastases (OR 4.21 [95%CI: 2.67 to 6.64]) after adjustment for all elevated B12-related causes. The strength of the association rose with the increasing B12 level, in particular in cases of metastases. No association between liver cancers and elevated B12 level was found after adjustment for chronic liver diseases. In conclusion, unexplained elevated B12 levels should be examined as a possible marker of solid cancer.

Nutritional neuropathies

Neuropathies associated with nutritional deficiencies are routinely encountered by the practicing neurologist. Although these neuropathies assume different patterns, most are length-dependent, sensory axonopathies. Cobalamin deficiency neuropathy is the exception, often presenting with a non-length-dependent sensory neuropathy. Patients with cobalamin and copper deficiency neuropathy characteristically have concomitant myelopathy, whereas vitamin E deficiency is uniquely associated with a spinocerebellar syndrome. In contrast to those nutrients for which deficiencies produce neuropathies, pyridoxine toxicity results in a non-length-dependent sensory neuronopathy. Deficiencies occur in the context of malnutrition, malabsorption, increased nutrient loss (such as with dialysis), autoimmune conditions such as pernicious anemia, and with certain drugs that inhibit nutrient absorption. When promptly identified, therapeutic nutrient supplementation may result in stabilization or improvement of these neuropathies.

Voluntary fortification is ineffective to maintain the vitamin B12 and folate status of older Irish adults: evidence from the Irish Longitudinal Study on Ageing (TILDA)

Mandatory fortification of staple grains with folic acid and/or vitamin B12 (B12) is under debate in many countries including Ireland, which has a liberal, but voluntary, fortification policy. Older adults can be at risk of both deficiency and high folate status, although little is known on the actual prevalence and the major predictors. Population prevalence estimates from older adults (n 5290 ≥50 years) from the Irish Longitudinal Study on Ageing (TILDA) (Wave 1) are presented here. Measures included plasma total vitamin B12 and folate, whereas predictors included detailed demographic, socio-economic, geographic, seasonal and health/lifestyle data. The prevalence of deficient or low B12 status (45 nmol/l) was observed in 8·9 %, whereas high B12 status was observed in 3·1 % (>601 pmol/l). The largest positive predictor of B12 concentration was self-reported B12 injection and/or supplement use (coefficient 51·5 pmol/; 95 % CI 9·4, 93·6; P=0·016) followed by sex and geographic location. The largest negative predictor was metformin use (-33·6; 95 % CI -51·9, -15·4; P<0·0001). The largest positive predictor of folate concentration was folic acid supplement use (6·0; 95 % CI 3·0, 9·0 nmol/l; P<0·001) followed by being female and statin medications. The largest negative predictor was geographic location (-5·7; 95 % CI -6·7, -4·6; P<0·0001) followed by seasonality and smoking. B-vitamin status in older adults is affected by health and lifestyle, medication, sampling period and geographic location. We observed a high prevalence of low B12 and folate status, indicating that the current policy of voluntary fortification is ineffective for older adults.

Hypervitaminosis B12 - a new marker and predictor of prognostically unfavorable diseases

A high serum vitamin B12 level (hypercobalaminemia) is a underestimated anomaly. Clinically, it can be paradoxically accompanied by signs of deficiency, which are related to defects in tissue uptake of vitamin B12. The increase in the level of serum cobalamin occurs mainly in serious diseases that require early diagnosis: hemoblastosis, liver and kidney diseases, etc. This review presents data on the metabolism of vitamin B12 and the potential significance of increasing its level as a marker for the early diagnosis of these diseases.

The Role of Micronutrients in the Infection and Subsequent Response to Hepatitis C Virus

Micronutrient deficiencies develop for a variety of reasons, whether geographic, socioeconomic, nutritional, or as a result of disease pathologies such as chronic viral infection. As micronutrients are essential for a strong immune response, deficiencies can significantly dampen both the innate and the adaptive arms of antiviral immunity. The innate immune response in particular is crucial to protect against hepatitis C virus (HCV), a hepatotropic virus that maintains chronic infection in up to 80% of individuals if left untreated. While many micronutrients are required for HCV replication, an overlapping group of micronutrients are also necessary to enact a potent immune response. As the liver is responsible for the storage and metabolism of many micronutrients, HCV persistence can influence the micronutrients’ steady state to benefit viral persistence both directly and by weakening the antiviral response. This review will focus on common micronutrients such as zinc, iron, copper, selenium, vitamin A, vitamin B12, vitamin D and vitamin E. We will explore their role in the pathogenesis of HCV infection and in the response to antiviral therapy. While chronic hepatitis C virus infection drives deficiencies in micronutrients such as zinc, selenium, vitamin A and B12, it also stimulates copper and iron excess; these micronutrients influence antioxidant, inflammatory and immune responses to HCV.

Profile of anemia in acute lymphoblastic leukemia patients on maintenance therapy and the effect of micronutrient supplementation

BACKGROUND

Anemia is a common finding and important cause of morbidity in patients with acute lymphoblastic leukemia (ALL) at diagnosis or during the course of its protracted treatment. We studied profile of anemia in ALL patients on maintenance therapy and evaluated specific micronutrients as cause of this anemia.

PATIENTS AND METHODS

ALL patients who were on maintenance therapy and had grade ≥ 2 anemia were recruited for the study. Serum iron studies, folate, and vitamin B12 were done to identify micronutrient deficiency and to initiate supplementation with specific components if found to be deficient. Toxicities, improvement of anemia, micronutrient levels, and disease outcome were studied after 3 months.

RESULTS

From March 2015 to September 2016, 105 ALL patients were found to be on maintenance fulfilling the inclusion criteria. Overall, the proportion of anemia was 80%(N = 84). Majority had normocytic normochromic anemia (71%). Macrocytic anemia was seen in 18% and microcytic hypochromic in 9.5%. In patients with anemia of grade ≥ 2 (N = 84), 38 patients (45%) had biochemical deficiency of serum folate, and 7 (8%) had vitamin B12 deficiency. No biochemical evidence of iron deficiency was found. Supplementation of deficient micronutrients improved anemia: mean hemoglobin significantly increased from 8.06 ± 1.63 to 10.78 ± 1.53 (p < 0.001) at 3 months; and reduced treatment toxicities, mean number of febrile neutropenia episodes (p = 0.007), and treatment interruptions of > 2 weeks (p = 0.002) were lowered. Patients with anemia had significantly more relapses (N = 14,64%) compared to patients without anemia (N = 8,36%), (p = 0.040).

CONCLUSION

Timely identification and correction of micronutrient deficiencies causing anemia in ALL patients on maintenance can enhance treatment outcomes.

Plasma B-vitamins and one-carbon metabolites and the risk of breast cancer in younger women

PURPOSE

We examined the association of plasma B-vitamins and metabolites, and related genetic variants, with risk of breast cancer among predominantly premenopausal women.

METHODS

We conducted a nested case-control study within the Nurses' Health Study II. From blood samples collected in 1996-1999 and follow-up through 2007, plasma measures were available for 610 cases and 1207 controls. Unconditional multivariable logistic regression was used to estimate relative risks (RR) of breast cancer and 95% confidence intervals (CIs). We examined whether associations varied by methylenetetrahydrofolate reductase (MTHFR) and dihydrofolate reductase polymorphisms, breast cancer risk factors, or tumor characteristics.

RESULTS

Plasma vitamin B₁₂ was associated with a 64% higher risk of breast cancer comparing the highest versus lowest quintile (95% CI 1.17-2.29, p-trend = 0.02). Plasma folate (comparable RR = 1.18, 95% CI 0.84-1.66), pyridoxal 5'-phosphate (RR = 1.18, 95% CI 0.85-1.64), homocysteine (RR = 0.93, 95% CI 0.67-1.28), cysteine (RR = 1.14, 95% CI 0.81-1.62), and cysteinylglycine (RR = 0.93, 95% CI 0.66-1.31) were not associated with overall breast cancer risk. Folate was significantly positively associated with invasive and estrogen receptor-positive/progesterone receptor-positive breast cancer, and this association was suggestively stronger for bloods collected post-fortification. Several nutrient/breast cancer associations varied across subgroups defined by age, smoking, alcohol, multivitamin use, and MTHFR status (p-interaction < 0.05).

CONCLUSIONS

Overall, plasma B-vitamins and metabolites were not associated with lower breast cancer risk. Plasma vitamin B-12 was positively associated with higher risk of overall breast cancer, and plasma folate was positively associated with risk of invasive breast cancer. Additionally, there may be associations in subgroups defined by related genetic variants, breast cancer risk factors, and tumor factors. Further studies in younger women and in the post-fortification era are needed to confirm these findings.

Elevated Vitamin B12 Levels and Cancer Risk in UK Primary Care: A THIN Database Cohort Study

BACKGROUND

Elevated vitamin B12 levels (B12) are associated with increased short-term cancer risk. However, the implications for early cancer detection in primary care have not been assessed.

METHODS

Individuals with plasma B12 measurements were sampled from The Health Improvement Network primary care database, UK. Persons with low B12 levels were excluded together with persons with cancer or B12 treatment before date of B12 measurement. Incident cancer was the outcome of interest and was identified through Read codes. Individuals were disaggregated according to plasma B12 levels (unit: pmol/L): 150-600 (reference range values), 601-800, 801-1,000, and >1,000.

RESULTS

Among the 757,185 persons who met the inclusion criteria, we identified 33,367 incident cancers during 2,874,059 years of follow-up. We found a higher 1-year cancer risk among the 25,783 (3.4%) persons with elevated B12 levels compared with those with normal B12 levels. After multivariable adjustment for lifestyle factors and social deprivation, persons with B12 >1,000 pmol/L had a 1-year incidence rate ratio of 4.72 (95% confidence interval: 3.99-5.58). The association showed a nonlinear dose-response pattern, and it remained robust in stratified analyses, including when reducing the risk of confounding by indication in subanalyses. The risks were particularly elevated for liver cancer, pancreas cancer, and myeloid malignancies among persons with elevated B12 levels.

CONCLUSIONS

Elevated plasma B12 levels were associated with a higher 1-year cancer risk than normal B12 levels among persons seen in UK primary care, suggesting that some cancers may affect B12 metabolism.

IMPACT

Elevated B12 may mark occult cancer.

Biomarkers of Nutrition for Development (BOND): Vitamin B-12 Review

This report on vitamin B-12 (B12) is part of the Biomarkers of Nutrition for Development (BOND) Project, which provides state-of-the art information and advice on the selection, use, and interpretation of biomarkers of nutrient exposure, status, and function. As with the other 5 reports in this series, which focused on iodine, folate, zinc, iron, and vitamin A, this B12 report was developed with the assistance of an expert panel (BOND B12 EP) and other experts who provided information during a consultation. The experts reviewed the existing literature in depth in order to consolidate existing relevant information on the biology of B12, including known and possible effects of insufficiency, and available and potential biomarkers of status. Unlike the situation for the other 5 nutrients reviewed during the BOND project, there has been relatively little previous attention paid to B12 status and its biomarkers, so this report is a landmark in terms of the consolidation and interpretation of the available information on B12 nutrition. Historically, most focus has been on diagnosis and treatment of clinical symptoms of B12 deficiency, which result primarily from pernicious anemia or strict vegetarianism. More recently, we have become aware of the high prevalence of B12 insufficiency in populations consuming low amounts of animal-source foods, which can be detected with ≥1 serum biomarker but presents the new challenge of identifying functional consequences that may require public health interventions.

Imaging Cobalamin Uptake within Malignant Breast Tumors In Vivo

PURPOSE

To image the uptake of cobalamin (Cbl) within malignant breast tumors in vivo.

PROCEDURES

Prior to surgery 20 female patients with clinically suspected breast tumors were intravenously administered 0.25 μg of an In-111 labeled 5-deoxyadenosylcobalamin (AC) analog ([¹¹¹In]AC) and sequentially imaged with whole-body planar (WBP) and single-photon emission computed tomography (SPECT) between 2-5 h and 20-24 h post-injection (P.I.). The tumor to background (T/B) ratio for [¹¹¹In]AC in breast tumors at 2-5 h was correlated to its expression of estrogen (ER), progesterone (PR), and human epidermal growth factor 2 (HER2) receptors. Subsequent pulse chase (PC) experiments in nude mice burdened with the MDA-MB-231 triple-negative (TN) breast tumor xenograft measured the effect that pulses of AC or dexamethasone (DEX) had on [¹¹¹In]AC uptake in both normal murine tissue and the TN breast tumor.

RESULTS

The mean [¹¹¹In]AC T/B ratio of the patients' 18 resected tumors was 5.8. Comparing ER- and PR-positive tumors (n = 11) to TN and HER2-positive tumors (n = 7), the mean [¹¹¹In]AC T/B ratios at 2-5 h P.I. were 3.2 (range 1.8-5.6) and 10.4 (range 3.3-22.5), respectively. Pulses of 2.0 μg of AC at 2, 8, or 24 h; or 40.0 μg of DEX at 24 h prior to injecting 0.5 μg of [¹¹¹In]AC, increased mean tracer uptake in the MDA-MB-231 tumors by 26.4, 71.5, 92.6, and 49.1 %, respectively. Only the 2- and 24-h PC intervals concomitantly suppressed [¹¹¹In]AC uptake in normal murine tissue while enhancing [¹¹¹In]AC uptake in MDA-MB-231 tumors.

CONCLUSION

The uptake of Cbl within malignant breast tumors can be imaged clinically. Cbl uptake is greatest in TN and HER2-positive breast tumors. A solitary bolus of AC or DEX increases the [¹¹¹In]AC uptake within a breast tumor in vivo. Investigating the cytogenetic mechanisms controlling the endocytosis of Cbl in malignant breast tumors is warranted.

Transcellular transport of cobalamin in aortic endothelial cells

Cobalamin [Cbl (or B₁₂)] deficiency causes megaloblastic anemia and a variety of neuropathies. However, homeostatic mechanisms of cyanocobalamin (CNCbl) and other Cbls by vascular endothelial cells are poorly understood. Herein, we describe our investigation into whether cultured bovine aortic endothelial cells (BAECs) perform transcytosis of B₁₂, namely, the complex formed between serum transcobalamin and B₁₂, designated as holo-transcobalamin (holo-TC). We show that cultured BAECs endocytose [⁵⁷Co]-CNCbl-TC (source material) via the CD320 receptor. The bound Cbl is transported across the cell both via exocytosis in its free form, [⁵⁷Co]-CNCbl, and via transcytosis as [⁵⁷Co]-CNCbl-TC. Transcellular mobilization of Cbl occurred in a bidirectional manner. A portion of the endocytosed [⁵⁷Co]-CNCbl was enzymatically processed by methylmalonic aciduria combined with homocystinuria type C (cblC) with subsequent formation of hydroxocobalamin, methylcobalamin, and adenosylcobalamin, which were also transported across the cell in a bidirectional manner. This demonstrates that transport mechanisms for Cbl in vascular endothelial cells do not discriminate between various β-axial ligands of the vitamin. Competition studies with apoprotein- and holo-TC and holo-intrinsic factor showed that only holo-TC was effective at inhibiting transcellular transport of Cbl. Incubation of BAECs with a blocking antibody against the extracellular domain of the CD320 receptor inhibited uptake and transcytosis by ∼40%. This study reveals that endothelial cells recycle uncommitted intracellular Cbl for downstream usage by other cell types and suggests that the endothelium is self-sufficient for the specific acquisition and subsequent distribution of circulating B₁₂ via the CD320 receptor. We posit that the endothelial lining of the vasculature is an essential component for the maintenance of serum-tissue homeostasis of B₁₂.-Hannibal, L., Bolisetty, K., Axhemi, A., DiBello, P. M., Quadros, E. V., Fedosov, S., Jacobsen, D. W. Transcellular transport of cobalamin in aortic endothelial cells.

The role of Vitamin B12 in the critically ill--a review

Vitamin B12 is an essential micronutrient, as humans have no capacity to produce the vitamin and it needs to be ingested from animal proteins. The ingested Vitamin B12 undergoes a complex process of absorption and assimilation. Vitamin B12 is essential for cellular function. Deficiency affects 15% of patients older than 65 and results in haematological and neurological disorders. Low levels of Vitamin B12 may also be an independent risk factor for coronary artery disease. High levels of Vitamin B12 are associated with inflammation and represent a poor outlook for critically ill patients. Treatment of Vitamin B12 deficiency is simple, but may be lifelong.

Vitamin B12 Deficiency Induced by the Use of Gastric Acid Inhibitors: Calcium Supplements as a Potential Effect Modifier

OBJECTIVE

Use of gastric acid inhibitors has emerged as a risk factor of vitamin B12 deficiency, especially in older adults. Calcium supplements could be an effect modifier of this relationship by its role in the absorption process of vitamin B12. The aim of this study is to examine whether the use of calcium supplements could be an effect modifier of the association between gastric acid inhibitors and vitamin B12 deficiency.

DESIGN

Cross-sectional study based on medical chart reviews.

SETTING

Geriatric Assessment Unit (GAU) of a university-affiliated hospital.

PARTICIPANTS

The study included 172 patients discharged from the GAU between 2008 and 2012.

MEASUREMENTS

Cases of vitamin B12 deficiency were identified as those who had received a diagnosis of vitamin B12 deficiency, and/or were receiving a treatment for vitamin B12 deficiency. Use of gastric acid inhibitors and calcium supplements at admission was determined from the pharmacist report. Associations between medications and vitamin B12 status were investigated using logistic regression models.

RESULTS

Seventy-one patients (41%) had vitamin B12 deficiency. At admission, 42% were taking gastric acid inhibitors and 45% calcium supplements. After adjustment for covariates, analyses revealed that vitamin B12 deficiency was more likely among users of gastric acid inhibitors who did not concomitantly received calcium supplements [OR=3.12; P=0.01]. Conversely, no significant association was observed in patients using both, gastric acid inhibitors and calcium supplements [OR=1.30; P=0.59].

CONCLUSIONS

The present study provides the very first evidence that the use of calcium supplements could be an effect modifier of the association between gastric acid inhibitors and vitamin B12 deficiency. Failure to consider calcium supplements as an effect modifier could have led to biased risk estimates in previous published studies.

Elevated plasma vitamin B12 levels and cancer prognosis: A population-based cohort study

BACKGROUND

Elevated plasma vitamin B12 levels (cobalamin, Cbl) are associated with increased short-term cancer risk among patients referred for this laboratory measurement. We aimed to assess prognosis in cancer patients with elevated plasma Cbl.

METHODS

We conducted a population-based cohort study using data from Danish medical registries during 1998-2014. The study included 25,017 patients with a cancer diagnosis and Cbl levels of 200-600 pmol/L (reference/normal range), 601-800 pmol/L and >800 pmol/L measured up to one year prior to diagnosis, and a comparison cohort of 61,988 cancer patients without a plasma Cbl measurement. Patients treated with Cbl were excluded. Survival probability was assessed using Kaplan-Meier curves. Mortality risk ratios (MRR) were computed using Cox proportional hazard regression, adjusted for age, sex, calendar year, cancer stage and comorbidity, scored using the Charlson comorbidity index.

RESULTS

Survival probabilities were lower among patients with elevated Cbl levels than among patients with normal levels and among members of the comparison cohort [(1-year survival,%) Cbl: 200-600 pmol/L: 69.3%; 601-800 pmol/L: 49.6%; >800 pmol/L: 35.8%; comparison cohort: 72.6%]. Thirty-day mortality was elevated for patients with Cbl levels of 601-800 pmol/L or >800 pmol/L, compared to patients with levels of 200-600 pmol/L [(MRR (95% confidence interval): 601-800 pmol/L vs. 200-600 pmol/L: 1.9 (1.6-2.2); >800 pmol/L vs. 200-600 pmol/L: 2.7 (2.4-3.1)]. This association remained robust for 31-90-day and 91-365-day mortality, showing similar dose-response patterns.

CONCLUSION

Cancer patients with elevated Cbl levels had higher mortality than those with normal Cbl levels. These findings may have clinical significance for assessing the prognosis of cancer patients.

Vitamin C Deficiency of Korean Homeless Patients Visiting to Emergency Department with Acute Alcohol Intoxication

Vitamins are essential micronutrients for maintenance of tissue functions. Vitamin deficiency is one of the most serious and common health problems among both chronic alcoholics and the homeless. However, the vitamin-level statuses of such people have been little studied. We evaluated the actual vitamin statuses of alcoholic homeless patients who visited an emergency department (ED). In this study the blood levels of vitamins B1, B12, B6, and C of 217 alcoholic homeless patients were evaluated retrospectively in a single urban teaching hospital ED. Vitamin C deficiency was observed in 84.3% of the patients. The vitamin B1, B12, and B6 deficiency rates, meanwhile, were 2.3%, 2.3%, and 23.5%, respectively. Comparing the admitted patients with those who were discharged, only the vitamin C level was lower. (P=0.003) In fact, the patients' vitamin C levels were markedly diminished, vitamin C replacement therapy for homeless patients should be considered in EDs.

The soluble transcobalamin receptor (sCD320) is present in cerebrospinal fluid and correlates to dementia-related biomarkers tau proteins and amyloid-beta

BACKGROUND

Cellular uptake of vitamin B12 (B12) demands binding of the vitamin to transcobalamin (TC) and recognition of TC-B12 (holoTC) by the receptor CD320. Recently, we identified a soluble form of CD320 (sCD320) in human plasma. Here we present data on the occurrence of this soluble receptor in cerebrospinal fluid (CSF) and show its correlations to dementia-related biomarkers tau proteins and amyloid-beta.

METHODS

We collected 223 cerebrospinal fluid samples and corresponding plasma samples (n = 46). We measured CSF and plasma sCD320, holoTC and total TC employing in-house ELISA methods and CSF phospho-tau (181P) (p-tau), total tau (t-tau) and amyloid-beta 1-42 (Aβ) (n = 177) employing commercial ELISA kits (Innogenetics Company). Size exclusion chromatography was performed on a Superdex 200 column.

RESULTS

The median sCD320 concentration in CSF (14 pmol/L) is around five times lower than in plasma (72 pmol/L). No correlation was observed between plasma and CSF sCD320 levels (n = 46), while the behavior upon size exclusion chromatography was the same. In CSF, sCD320 correlates to holoTC and total TC (Spearman's correlation (Rs) = 0.325, 0.232 (n = 218, 217) respectively, p < 0.01). Interestingly, sCD320 correlates to p-tau and t-tau (Rs = 0.599, 0.569 (n = 173, 176) respectively, p < 0.001) and to Aβ (Rs = 0.265, p < 0.001 (n = 177)).

CONCLUSION

We document for the first time the occurrence of sCD320 in human CSF. We report that the concentration of sCD320 correlates to the dementia-related biomarkers p-tau, t-tau and Aβ.

Paradoxical increase of plasma vitamin B12 and folates with disease severity in anorexia nervosa

OBJECTIVE

Anorexia nervosa (AN) is a complex disorder involving severe psychological manifestations and multiple organ damage, including liver dysfunction. The primary aim of this study consisted in assessing plasma levels of vitamin B12 and folates with respect to liver function enzymes considering the liver-storage properties of this vitamin.

METHOD

We recruited 70 restrictive type AN adolescents and the severity of psychopathological traits was assessed using EDI-3 scale. Plasma levels of vitamin B12 , folates, transaminases (AST, ALT), gamma-glutamyl transpeptidase (GGT), alkaline phosphatase (ALP) and cholinesterase (CHE) were determined.

RESULTS

About 38.5% of patients displayed vitamin B12 values (H-B12) above the upper range of normal reference; 4.3% of patients had increased values of folates; 20 and 11.4% of patients displayed ALT and AST values above reference limits; none had GGT values above normal range. Albeit low CHE and ALP values were found in 55 and 20% of patients, respectively, a linear correlation with both transaminases was present only for vitamin B12 and folates; furthermore, H-B12 patients had both higher AST and ALT values. EDI- 3 subscores significantly correlated with vitamin B12 and folates plasma values and H-B12 patients displayed EDI-3 higher values.

DISCUSSION

These data suggest that plasma levels of vitamin B12 might be an early marker of liver dysfunction, possibly also related to more severe psychopathological aspects. The identification of patients with higher fasting plasma vitamin B12 levels could therefore lead to earlier and more careful refeeding interventions. Further studies will clarify the potential role of this vitamin in AN clinical practice.

Hypercobalaminaemia is associated with hepatic and neoplastic disease in cats: a cross sectional study

Background

When increased serum cobalamin concentrations are encountered clinically they are usually attributed to parenteral supplementation, dietary factors, or otherwise ignored. However, recently, hypercobalaminaemia has been associated with numerous diseases in humans, most notably neoplastic and hepatic disorders. The aim of this retrospective, observational, cross-sectional study was to determine the significance of increased cobalamin in cats.

Results

In total, 237 records were retrieved and 174 cats, of various ages and sexes met the inclusion criteria. A total of 42 cats had increased serum cobalamin concentration, and had not received prior supplementation. Multiple logistic regression analysis revealed that increased serum cobalamin concentration was positively related to pedigree breed (pedigree breeds more likely to have increased cobalamin concentration, odds ratio [OR] 4.24, 95% CI 1.78-10.15, P = 0.001), to having liver disease (OR 9.91, 95% CI 3.54-27.68), and to having a solid neoplasm (OR 8.54, 95% CI 1.10-66.45).

Conclusions

The results of the current study suggest that increased serum cobalamin concentrations should not be ignored in cats with no history of supplementation, and investigation for underlying hepatic or neoplastic disease is warranted.

High vitamin B12 levels are not associated with increased mortality risk for ICU patients after adjusting for liver function: a cohort study

BACKGROUND AND AIMS

Recent research has suggested that high vitamin B12 levels may be associated with increased mortality after ICU admission. However, it is known that impaired liver function may lead to elevated B12 since B12 is metabolized through the liver, and therefore high B12 levels may serve as a proxy for poor liver function. The aim of this study is to assess the impact that liver function and liver disease have on the relationship between high vitamin B12 levels and mortality in the ICU.

METHODS

We performed an observational cohort study using ICU data that were collected from patients admitted to four ICU types (medical, surgical, cardiac care and cardiac surgery recovery) in one large urban hospital from 2001 to 2008. We analyzed the medical records of 1,684 adult patients (age ≥ 18 years) who had vitamin B12 and liver function measurements up to 14 days prior to ICU admission or within 24 hours after admission.

RESULTS

While we found an association between high B12 and mortality when we did not control for any potential confounders, after we adjusted for liver function and liver disease, no significant association existed between B12 and mortality using multivariable logistic regression (30-day mortality: OR=1.18, 95% CI 0.81 to 1.72, p=0.3890; 90-day mortality: OR=1.20, 95% CI 0.84 to 1.71, p=0.3077).

CONCLUSIONS

Elevated B12 levels are not a significant predictor of mortality after ICU admission when liver function is controlled for, and may instead be a proxy for poor liver function.