Folic acid and vitamin B12 supplementation in subjects with type 2 diabetes mellitus: A multi-arm randomized controlled clinical trial

Vitamin B12 status and metabolic health in women of reproductive age: Population-based biomarker survey

BACKGROUND AND AIMS

In clinical populations, vitamin B12 deficiency has been associated with adverse metabolic health (e.g., gestational diabetes). Population-level data among women of reproductive age could inform screening and interventions. The objective of this analysis was to examine the prevalence of adverse metabolic characteristics (elevated adiposity and central adiposity, hypertension, elevated glycated hemoglobin [HbA1c]) and associations of vitamin B12 status with metabolic characteristics in women as part of a population-based biomarker survey in Southern India.

METHODS

Participants (n = 980 women 15-40 y; not pregnant or lactating) were assessed for total vitamin B12, holotranscobalamin, methylmalonic acid, homocysteine, and HbA1c. Categorical anthropometry assessments and bioelectrical impedance analysis (e.g., whole body (WF%) and trunk (TF%) fat) were assessed among adults (≥18 y). Linear and binomial regressions were used to examine associations of vitamin B12 status with metabolic characteristics.

RESULTS

Overall, 25 % of participants had HbA1c ≥5.7 % (HbA1c ≥5.7-<6.5 %: 20.0 %; ≥6.5 %: 5.0 %), and 18.6 % had hypertension (Stage 1: 16.4 %; Stage 2: 2.2 %). Among adults, 23.4 % had body mass index of (BMI) 25.0-<30.0 kg/m2, 9.6 % had BMI ≥30.0 kg/m2, 13.4 % had elevated waist circumference (WC; >88.9 cm), and 20.8 % had elevated waist-hip ratio (WHR; ≥0.85 cm). Overall, higher vitamin B12 concentrations were associated with lower BMI and WC. Among adults, higher vitamin B12 concentrations were associated with lower WF% and TF%; and lower prevalence of overweight (BMI ≥25.0 kg/m2) and elevated WC, WHR, and WF%. Similarly, vitamin B12 <148 pmol/L was associated with higher BMI and WC overall and, among adults, higher WF% and TF%, and increased overweight (BMI ≥25.0 kg/m2; prevalence ratio: 1.31; 95 % confidence interval: 1.09-1.58), and elevated WC (>88.9 cm; 1.85 [1.32-2.60]), WHR (≥85.0; 1.38 [1.07-1.78]), WF% (>35 %; 1.29 [1.10-1.51]), and TF% (>35 %; 1.25 [1.06-1.49]).

CONCLUSIONS

The burden of adverse metabolic characteristics was substantial in this population of young, apparently healthy women. Among those with vitamin B12 <148 pmol/L there was increased central adiposity and overweight status. Evaluating vitamin B12 and metabolic outcomes prospectively could inform screening and interventions to improve women's health.

REGISTRATION NUMBER

NCT04048330.

The unexpected role of B vitamins in osteoarthritis: a call for caution

Background: The purpose of this study was to investigate the single and mixed effects of B vitamins on OA. Methods: Data from the National Health and Nutrition Examination Survey (NHANES) database, from 2003 to 2018, were extracted. A weighted multiple logistic regression model was used to assess the association between B vitamin intake alone and OA. In addition, Bayesian kernel machine regression (BKMR), weighted quantile sum (WQS) regression and quantile g-calculation (qgcomp) models were used to evaluate the combined effects of six B vitamins on OA. Additionally, restricted cubic spline (RCS) was used to assess possible nonlinear associations between individual B vitamins and OA. Results: The study found that vitamin B1 (OR = 1.17, 95%CI = 1.05-1.30), vitamin B2 (OR = 1.12, 95%CI = 1.02-1.22), vitamin B12 (OR = 1.01, 95%CI = 1.00-1.01) and total folate (OR = 1.001, 95%CI = 1.000-1.001) increased the risk of OA. Subgroup analysis showed that the association was more significant in people older than 65 and in women. In addition, the mixed effect model also suggested that the mixed effect of six B vitamin mixtures on OA risk was greater. Among them, vitamin B2 and vitamin B12 contributed the most to the promotion of OA disease by B-complex vitamins. Folic acid, however, showed a protective effect on the bone and joints in the mixed effect model. Conclusion: The data show that the intake of B vitamins accelerates the occurrence and progression of OA. People with OA disease and those at high risk should be cautious about using vitamin B as a dietary supplement.

Biological, dietetic and pharmacological properties of vitamin B9

Humans must obtain vitamin B9 (folate) from plant-based diet. The sources as well as the effect of food processing are discussed in detail. Industrial production, fortification and biofortification, kinetics, and physiological role in humans are described. As folate deficiency leads to several pathological states, current opinions toward prevention through fortification are discussed. Claimed risks of increased folate intake are mentioned as well as analytical ways for measurement of folate.

A randomized multi-arm open labelled comparative clinical trial report of Pankajakasthuri DiabetEaze powder, a novel polyherbal formulation on the nutritional management and glycemic control in type 2 diabetic and prediabetic patients

Background and aims

Recently Diabetes Mellitus (DM) has been associated with heightened susceptibility to malnutrition, suggesting that augmenting nutritional intake stands out as a potent therapeutic strategy for addressing malnutrition in individuals with DM. The aim of this clinical investigation was to evaluate the effect of DiabetEaze powder, a polyherbal nutritional formulation developed by us for nutritional management and glycaemic control, on patients with diabetic and prediabetic conditions.

Methods

A total of 143 type II diabetic (T2D) patients who were managing their diabetic condition through modern medicine, AYUSH medicine, lifestyle modification and 68 pre-diabetic patients, aged between 40 and 65 years, were randomly assigned into six groups: control, modern, AYUSH, lifestyle, prediabetic control and prediabetic trial. The treatment groups were administered 5 g of DiabetEaze powder two times a day after food for 6 months. Microminerals, vitamins, glycaemic parameters, Quality of Life (QoL), hematology, lipid profiles, Renal Function Test (RFT) and Liver Function Test (LFL) parameters, and electrolytes were evaluated at Day 0, Day 90, and Day 180.

Results

Out of 211 enrolled patients, 189 individuals successfully completed the entire 180-day duration of the study, indicating a retention rate of approximately 89.6 %. In our study, we observed a statistically significant elevation in the levels of vitamin D, B2, and B6 across all treatment groups. Besides, the treatment groups displayed a notable increase in zinc and manganese levels compared to the other minerals tested. Notably, the treatment groups demonstrated distinct mineral and vitamin profiles. In terms of metabolic markers, significant reductions in Fasting Blood Sugar (FBS)/Post Prandial Blood Sugar (PPBS) were observed across the modern, AYUSH, and lifestyle groups, while the modern group also showed a marked decrease in glycated haemoglobin (HbA1c) levels. Furthermore, overall QoL among the tested groups was also statistically significant. The consistent maintenance of normal LFT and RFT parameters and electrolyte levels across trial groups throughout the study duration indicates that the supplement does not induce liver toxicity or negatively impact hepatic function.

Conclusion

In conclusion, the nutrients present in the DiabetEaze powder contribute to the effective management of nutritional status in diabetic people and thus effectively reduce sugar spikes by regulating PPBS and HbA1c levels, which is a critical aspect of its role in diabetes management. These properties benefit in managing diabetes-related outcomes and overall quality of life.

Clinical trial registry of India under registration no

CTRI/2021/04/032956 on 20/04/2021.

Vitamin B12 is correlated with insulin resistance and metabolism disorder markers in women with recurrent pregnancy loss

OBJECTIVES

Recurrent pregnancy loss (RPL) seriously affects women's reproductive and mental health, and the incidence has increased in recent years. Insulin resistance (IR) acts as a significant contributing factor to RPL. Studies suggest that vitamin B12, folate intake, and homocysteine are correlated with IR, but the exact nature remains controversial and requires further investigation. In this study, we aimed to assess the levels and correlations between vitamin B12-folate-homocysteine and insulin resistance in RPL patients.

STUDY DESIGN

73 control subjects and 256 RPL patients (144 RPL patients without IR and 112 RPL patients with IR) were included in this observational retrospective cross-sectional study. The differences in vitamin B12, folate, and homocysteine levels between RPL patients with and without IR were analyzed using a Student's t-test. Pearson correlations were utilized to examine the correlation between vitamin B12-folate-homocysteine and glucose and lipid metabolism parameters. Multivariable linear regressions were used to assess the independent correlation of each factor with HOMA-IR.

RESULTS

Compared to the control subjects, RPL patients exhibited lower vitamin B12 (p < 0.001) and folate (p < 0.001), and higher homocysteine (p = 0.001). RPL patients with IR described decreases in vitamin B12 (p = 0.003) and folate (p = 0.028), and increases in homocysteine (p = 0.033) as RPL patients without IR. Vitamin B12 in RPL patients was significantly negatively correlated with homocysteine (r = -0.348, p < 0.001), HOMA-IR (r = -0.214, p < 0.001), BMI (r = -0.160, p = 0.017), TG (r = -0.148, p = 0.039) and CHO (r = -0.149, p = 0.038) and positively correlated with folate (r = 0.217, p < 0.001). In multivariable linear regressions, after adjusting for age, strong correlations were observed between vitamin B12 (β = -0.197, p = 0.010), BMI (β = 0.466, p < 0.001), and HOMA-IR in RPL patients.

CONCLUSION

Vitamin B12 is significantly correlated with IR in RPL patients. Circulating vitamin B12-folate-homocysteine metabolism could be a window of the pathological process of IR, obesity, and lipid metabolism disorders in RPL patients.

Folic Acid as a Potential Vitamin in Glycemic Control: A Systematic Review

PURPOSE

This systematic review aims to examine the relationship between serum folate level and folic acid supplements with glycemic control parameters (fasting blood glucose (FBG), insulin level, Homeostatic Model Assessment for Insulin Resistance (HOMA-IR), and Hemoglobin A1C (HbA1c)) in adult individuals with current studies.

METHODS

In this study, which was designed as a systematic review, the searches were performed on Web of Science, Science Direct, Medline, Wiley, and Cochrane Library databases between April 10, 2023, and May 10, 2023, and the searches were updated between October 16, 2023, and November 14, 2023. Of the 1855 studies obtained from the screening, 17 met the criteria and were included in the systematic review. The PROSPERO system registered the study protocol (ID: CRD42023472434).

RECENT FINDINGS

Although no significant correlation was found between serum folate levels and glycemic control parameters in most of the cross-sectional studies included in this systematic review, most of the randomized controlled trials showed that glycemic control parameters (FBG, insulin, HOMA-IR) decreased significantly in the intervention group receiving folic acid supplementation compared to the control group. However, study durations were short, and HbA1c needed to be evaluated in most studies. This makes it difficult to get information about the long-term effects of folic acid supplementation. More comprehensive studies should be conducted to draw more precise conclusions about the relationship between folic acid levels and folic acid supplementation with glycemic control parameters.

Exploring the Link Between Vitamin B Levels and Metabolic Syndrome Risk: Insights from a Case-Control Study in Kazakhstan

Background/Objectives: Metabolic syndrome (MS) is a collection of metabolic disorders that include insulin resistance, central obesity, dyslipidemia, and hypertension. The prevalence of MS affects 20-30% of adults worldwide, leading to serious health, social, and economic issues. Mitochondrial dysfunction, characterized by mitochondrial DNA (mtDNA) mutations and altered dynamics, plays a pivotal role in MS by impairing glucose oxidation. B vitamins are crucial for optimal mitochondrial function and overall metabolic processes, particularly within the context of MS. This study aims to investigate the associations between plasma concentrations of B vitamins and the risk of MS within the Kazakh population. Methods: In this case-control study, biochemistry measurements included serum fasting glucose, HbA1c, creatinine, and lipid profile parameters. The sample comprised individuals who agreed to participate in the investigation and at the Semey polyclinic between December 2022 to March 2024. A total of 190 Kazakhs aged 35-65 years old, including 104 subjects with MS and 86 without MS, took part in the study. Results: In a comparative analysis of serum vitamin B levels against established reference ranges, the following results were observed: 95% of participants exhibited vitamin B2 levels at the lower limit of normal, while 4.59% were classified as low. For vitamin B3, 95.77% showed low levels, with only 4.23% in the normal range. Vitamin B6 levels were low in 76.02% of participants. In contrast, 92.82% had normal serum levels of vitamin B9. Regarding vitamin B12, 38.82% had normal levels, 59.41% had elevated levels, and 1.76% were classified as low. Among the evaluated vitamins, only vitamin B2 showed a significant correlation with the risk of developing MS, with an OR of 1.79 (95% CI 1.003, 3.19, p = 0.05). Conclusions: Relatively elevated serum levels of vitamin B2 at the lower limit of the normal range are associated with a 1.8-fold increased risk of developing MS.

Prospecting Specific Protein Patterns for High Body Mass Index (BMI), Metabolic Syndrome and Type 2 Diabetes in Saliva and Blood Plasma From a Brazilian Population

PURPOSE

Obesity and its associated metabolic disorders, such as T2DM and MeS, are a growing public health problem worldwide. Our goal was the identification of protein patterns that are uniquely characteristic of higher BMI, MeS, and T2DM in a Brazilian population.

EXPERIMENTAL DESIGN

Saliva and plasma proteomes, clinical parameters were analyzed in a population from the state of Rio de Janeiro, Brazil, a mixed-race population. Volunteers were sorted by their BMI into normal (n = 29), overweight (n = 25), and obese (n = 15) and were compared with individuals with MeS (n = 23) and T2DM (n = 11).

RESULTS

The Random Forest (RF) predictive model revealed that three clinical variables, BMI, HOMA-IR, and fasting blood glucose, are most important for predicting MeS and T2DM. A total of six plasmatic proteins (ABCD4, LDB1, PDZ, podoplanin, lipirin-alpha-3, and WRS) and six salivary proteins (hemoglobin subunit beta, POTEE, T cell receptor alpha variable 9-2, lactotransferrin, cystatin-S, carbonic anhydrase 6), are enhanced in T2DM and in MeS.

CONCLUSIONS AND CLINICAL RELEVANCE

Our data revealed similar alterations in protein composition across individuals with abnormal weight gain, T2DM, and MeS. This finding confirms the close link between these conditions at the molecular level in the studied population, potentially enhancing our understanding of these diseases and paving the way for the development of novel diagnostic tools.

The Antioxidant Potential of Vitamins and Their Implication in Metabolic Abnormalities

Vitamins are micronutrients necessary for the normal function of the body. Although each vitamin has different physicochemical properties and a specific role in maintaining life, they may also possess a common characteristic, i.e., antioxidant activity. Oxidative stress can harm all the main biological structures leading to protein, DNA and lipid oxidation, with concomitant impairment of the cell. It has been established that oxidative stress is implicated in several pathological conditions such as atherosclerosis, diabetes, obesity, inflammation and metabolic syndrome. In this review we investigate the influence of oxidative stress on the above conditions, examine the interrelation between oxidative stress and inflammation and point out the importance of vitamins in these processes, especially in oxidative load manipulation and metabolic abnormalities.

A comprehensive review and meta-regression analysis of randomized controlled trials examining the impact of vitamin B12 supplementation on homocysteine levels

CONTEXT

Although some research suggests that vitamin B12 (hereafter, B12) supplements can lower homocysteine (Hcy) levels and treat hyperhomocysteinemia, these results are still ambiguous when B12 is taken as an isolated supplement.

OBJECTIVE

This study sought to determine how existing randomized controlled trials (RCTs) could be used to examine the effects of B12 supplementation on Hcy.

DATA SOURCES

To find pertinent RCTs up to June 2022, databases, including PubMed/Medline, Web of Science, Scopus, Cochrane Library, and Embase, were searched.

DATA EXTRACTION

All selected RCTs investigated the impact of B12 supplements on Hcy. A meta-analysis of the eligible studies was performed using the random-effects model.

DATA ANALYSIS

This review included a total of 21 RCTs (N = 1625 participants). Hcy levels were significantly lower after B12 supplementation compared with the control group (pooled weighted mean difference, -4.15 μmol/L; 95% confidence interval, -4.86, -3.45; P < 0.001), and this reduction was even greater with intervention durations ≥12 weeks and doses >500 µg/d. Furthermore, the effect of B12 supplementation in the form of hydroxocobalamin on the reduction of Hcy level was greater compared with other forms.

CONCLUSION

In conclusion, this meta-analysis shows that B12 supplementation has a positive impact on lowering blood Hcy levels, particularly when administered for a longer period and at a larger dose.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42022364066.

Folic acid supplementation on inflammation and homocysteine in type 2 diabetes mellitus: systematic review and meta-analysis of randomized controlled trials

BACKGROUND

The beneficial effects of folate have been observed under different conditions, but the available evidence on inflammation and reduction of cardiovascular disease (CVD) in type 2 diabetes mellitus (T2DM) is limited. The study aimed to explore the effects of folate on inflammation and homocysteine amongst individuals with T2DM.

METHODS

PubMed, Scopus, and Cochrane Library were used to search for evidence. A random-effect model meta-analysis through Review Manager (version 5.4) and metaHun was performed. Results were reported as standardized mean differences (SMD) and 95% confidence intervals graphically using forest and funnel plots.

RESULTS

Data from 9 trials with 426 patients living with T2DM were analyzed. Folic acid supplementation significantly revealed a large effect size on homocysteine levels compared to placebo, SMD = -1.53, 95%CI (-2.14,-0.93), p < 0.05. Additionally, we observed a medium marginal effect size on C-reactive protein (SMD = -0.68, 95%CI (-1.34, -0.01), p = 0.05). However, no significant effect on tumor necrosis factor-α (SMD = -0.86, 95%CI (-2.65, 0.93), p = 0.34), and interleukin-6 (SMD = -0.04, 95%CI (-1.08, 1.01), p = 0.95) was observed.

CONCLUSION

Evidence analyzed in this study suggests that folic acid supplementation in T2DM reduces homocysteine and may mitigate CVDs. However, its effect on inflammation is inconclusive.

The Role of Organokines in Obesity and Type 2 Diabetes and Their Functions as Molecular Transducers of Nutrition and Exercise

Maintaining systemic homeostasis requires the coordination of different organs and tissues in the body. Our bodies rely on complex inter-organ communications to adapt to perturbations or changes in metabolic homeostasis. Consequently, the liver, muscle, and adipose tissues produce and secrete specific organokines such as hepatokines, myokines, and adipokines in response to nutritional and environmental stimuli. Emerging evidence suggests that dysregulation of the interplay of organokines between organs is associated with the pathophysiology of obesity and type 2 diabetes (T2D). Strategies aimed at remodeling organokines may be effective therapeutic interventions. Diet modification and exercise have been established as the first-line therapeutic intervention to prevent or treat metabolic diseases. This review summarizes the current knowledge on organokines secreted by the liver, muscle, and adipose tissues in obesity and T2D. Additionally, we highlighted the effects of diet/nutrition and exercise on the remodeling of organokines in obesity and T2D. Specifically, we investigated the ameliorative effects of caloric restriction, selective nutrients including ω3 PUFAs, selenium, vitamins, and metabolites of vitamins, and acute/chronic exercise on the dysregulation of organokines in obesity and T2D. Finally, this study dissected the underlying molecular mechanisms by which nutrition and exercise regulate the expression and secretion of organokines in specific tissues.

Identification of Dietary Supplements Associated with Blood Metabolites in the Hispanic Community Health Study/Study of Latinos Cohort Study

BACKGROUND

Metabolomics approaches have been widely used to define the consumption of foods but have less often been used to study exposure to dietary supplements.

OBJECTIVES

This study aimed to identify dietary supplements associated with metabolite levels and to examine whether these metabolites predicted incident diabetes risk.

METHODS

We studied 3972 participants from a prospective cohort study of 18-74-y-old Hispanic/Latino adults. At a baseline examination, we ascertained use of dietary supplements using recall methods and concurrently, a serum metabolomic panel. After adjustment for potential confounders, we identified dietary supplements associated with metabolites. We then examined the association of these metabolites with incident diabetes at the 6-y study examination.

RESULTS

We observed a total of 110 dietary supplement-metabolite associations that met the criteria for statistical significance adjusted for age, sex, field center, Hispanic/Latino background, body mass index, diet, smoking, physical activity, and number of medications (adjusted P < 0.05). This included 13 metabolites uniquely associated with only one dietary supplement ingredient. Vitamin C had the most associated metabolites (n = 15), including positive associations with oxalate, tartronate, threonate, and isocitrate, which were each in turn protective for the risk of incident diabetes. Vitamin C was also associated with higher N-acetylvaline level, which was an unfavorable diabetes risk factor. Other findings related to branched chain amino acid related compounds including α-hydroxyisovalerate and 2-hydroxy-3-methylvalerate, which were inversely associated with thiamine or riboflavin intake and also predicted higher diabetes risk. Vitamin B12 had an inverse association with γ-glutamylvaline, levels of which were positively associated with the risk of diabetes.

CONCLUSIONS

Our data point to potential metabolite changes associated with vitamin C and B vitamins, which may have favorable metabolic effects. Knowledge of blood metabolites that can be modified by dietary supplement intake may aid understanding the health effects of dietary supplements and identify potential biological mediators.

Periconceptional biomarkers for maternal obesity: a systematic review

Periconceptional maternal obesity is linked to adverse maternal and neonatal outcomes. Identifying periconceptional biomarkers of pathways affected by maternal obesity can unravel pathophysiologic mechanisms and identify individuals at risk of adverse clinical outcomes. The literature was systematically reviewed to identify periconceptional biomarkers of the endocrine, inflammatory and one-carbon metabolic pathways influenced by maternal obesity. A search was conducted in Embase, Ovid Medline All, Web of Science Core Collection and Cochrane Central Register of Controlled Trials databases, complemented by manual search in PubMed until December 31^st, 2020. Eligible studies were those that measured biomarker(s) in relation to maternal obesity, overweight/obesity or body mass index (BMI) during the periconceptional period (14 weeks preconception until 14 weeks post conception). The ErasmusAGE score was used to assess the quality of included studies. Fifty-one articles were included that evaluated over 40 biomarkers. Endocrine biomarkers associated with maternal obesity included leptin, insulin, thyroid stimulating hormone, adiponectin, progesterone, free T4 and human chorionic gonadotropin. C-reactive protein was associated with obesity as part of the inflammatory pathway, while the associated one-carbon metabolism biomarkers were folate and vitamin B12. BMI was positively associated with leptin, C-reactive protein and insulin resistance, and negatively associated with Free T4, progesterone and human chorionic gonadotropin. Concerning the remaining studied biomarkers, strong conclusions could not be established due to limited or contradictory data. Future research should focus on determining the predictive value of the optimal set of biomarkers for their use in clinical settings. The most promising biomarkers include leptin, adiponectin, human chorionic gonadotropin, insulin, progesterone and CRP.

Meta-analysis of Serum Vitamin B12 Levels and Diabetic Retinopathy in Type 2 Diabetes

BACKGROUND

Previous studies have shown an association between low serum vitamin B12 levels and the risk of diabetic retinopathy (DR) in type 2 diabetes, but the conclusions from various studies were inconsistent. Therefore, we collected relevant data from various databases to perform a meta-analysis and address the inconsistencies in these studies.

METHODS

We searched PubMed, Embase, Cochrane Library, CNKI, Wanfang and CQVIP for eligible studies published up to April 10, 2022, and performed a meta-analysis using Stata software to assess the association between serum vitamin B12 levels and DR.

RESULTS

A total of 15 studies were included in this meta-analysis. Statistical analysis showed that serum vitamin B12 levels were significantly reduced in patients with type 2 diabetic retinopathy ,WMD 95% CI = -68.91 (-76.76, -61.06) (p <0.00001, I² = 88.30%). In subgroup analyses by ethnicity, an association between low serum vitamin B12 levels and DR risk was found in East Asian, South Asian and mixed populations, but not in Caucasian populations.

CONCLUSIONS

This meta-analysis analyzed vitamin B12 in patients with type 2 diabetic retinopathy and emphasized the importance of monitoring serum vitamin B12 levels in patients with type 2 diabetic retinopathy, but this meta-analysis still has deficiencies and limitations, and more clinical studies are needed to confirm this conclusion in the future.

Association between dietary intake of one-carbon metabolism nutrients and hyperglycemia in coal-burning fluorosis areas of Guizhou, China

Background and aims

There are limited studies describing the association between dietary intake of one-carbon metabolism nutrients and hyperglycemia. The present study aimed to investigate the association of habitual dietary intake of one-carbon metabolism nutrients with hyperglycemia in a fluorosis area in China, and explored the interaction between these nutrients and fluorosis related to hyperglycemia.

Method

In a cross-sectional study, we recruited 901 villagers, ages ranging from 18–75, in Guizhou Province. Dietary data and other covariate data were obtained through an interviewer-administered questionnaire. We collected venous blood samples from participants who had fasted for one night to obtain fasting blood glucose levels and we categorized dietary intake of betaine, total choline, methionine, folate, vitamins B₆ and B₁₂, and choline subclasses into quartiles (Q1–Q4). The lowest quartile (Q1) served as the reference group. An unconditional logistic regression model was used to evaluate the protective effects of a dietary intake of one-carbon nutrients against hyperglycemia. We calculated Odds Ratios (ORs) with 95% confidence intervals (CIs). A presence or absence of fluorosis subgroup analysis was performed to determine the potential effect of fluorosis on hyperglycemia.

Result

After adjusting for potential confounding factors, we found that a greater intake of dietary vitamin B₆, total choline and methyl-donor index was inversely associated with the occurrence of hyperglycemia (P-trend <0.05). However, there were no significant associations between hyperglycemia and the dietary intake of folate, vitamin B₁₂, methionine, and betaine. As for the choline subgroups, it showed that the dietary intake of free choline, phosphatidylcholine, and glycerol phosphatidylcholine was negatively correlated with the occurrence of hyperglycemia (P < 0.05). In contrast, there was no statistical association between dietary phosphatidylcholine and sphingomyelin and hyperglycemia (all P > 0.05). The results of subgroup analysis showed that dietary intake of folate, vitamin B₆, total choline, free choline, glycerol phosphorylcholine, and phosphocholine had a protective effect against the occurrence of hyperglycemia in the non-fluorosis subgroup, although no effects were observed in the fluorosis subgroup. There were significant interactions between these nutrients and fluorosis (P = 0.010–0.048).

Conclusion

The study demonstrated that higher dietary intake of vitamin B₆, total choline, methyl-donor index, free choline, glycerol phosphorylcholine, and phosphocholine in choline compounds were associated with a lower incidence of hyperglycemia. Moreover, the associations were modified by the presence or absence of fluorosis. Further investigation is needed to test the association in large-scale follow-up studies.

The efficacy of vitamin B12 supplementation for treating vitamin B12 deficiency and peripheral neuropathy in metformin-treated type 2 diabetes mellitus patients: A systematic review

BACKGROUND AND AIMS

Metformin-treated type 2 diabetes mellitus (T2DM) patients are at higher risk of vitamin B₁₂ deficiency and more severe neuropathy symptoms. There is still no guideline suggesting vitamin B₁₂ supplementation for this population. This study aimed to analyze the efficacy of vitamin B₁₂ supplementation in this population.

METHOD

Studies reporting the efficacy of vitamin B₁₂ supplementation in metformin-treated T2DM patients were systematically searched in PubMed, Cochrane, EBSCOHost, and Scopus following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. Additional relevant studies were searched manually through citations. Study quality and risk of bias were assessed using suitable tools.

RESULTS

Seven clinical trials with a total of 506 participants were included. Using the Cochrane's Risk of Bias 2 tools for clinical trials, 4 studies were assessed to have high risk of bias and 3 studies had low risk of bias. There were 5 studies that measured changes in serum vitamin B₁₂ level, all of which reported a statistically significant increase after supplementation. Significant reductions in homocysteine after supplementation were found in 2 studies. Its effect on neuropathy symptoms was still unclear, with 2 studies reporting a significant improvement and 1 study reporting no significant effect.

CONCLUSIONS

The results of this systematic review support the implementation of vitamin B₁₂ supplementation for metformin-treated T2DM to prevent or treat vitamin B₁₂ deficiency and neuropathy. More high-quality clinical studies are required to generate quantitative analysis and to encourage supplementation in available guidelines.

The effects of vitamin B12 supplementation on metabolic profile of patients with non-alcoholic fatty liver disease: a randomized controlled trial

The present study is the first effort to evaluate the effects of vitamin B12 supplementation on the serum level of liver enzymes, homocysteine, grade of hepatic steatosis, and metabolic profiles in patients with non-alcoholic fatty liver disease (NAFLD). Forty patients with NAFLD were enrolled in a double-blind placebo-controlled trial to receive either one oral tablet of vitamin B12 (1000 µg cyanocobalamin) or a placebo per day for 12 weeks. We investigated serum levels of homocysteine, aminotransferases, fasting blood glucose (FBG), lipids, malondialdehyde (MDA), and homeostasis model assessment of insulin resistance (HOMA-IR). The grade of liver steatosis and fibrosis was measured by real-time 2-dimensional shear wave elastography. Vitamin B12 supplementation significantly decreased serum levels of homocysteine compared to placebo (medians: - 2.1 vs. - 0.003 µmol/l; P = 0.038). Although serum alanine transaminase (ALT) in the vitamin B12 group decreased significantly, this change did not reach a significant level compared to the placebo group (medians: - 7.0 vs. 0.0 IU/l; P > 0.05). Despite the significant within-group decrease in FBG, MDA, and liver steatosis in the vitamin B12 group, between-group comparisons did not reveal any significant difference. Vitamin B12 supplementation might decrease serum levels of homocysteine in patients with NAFLD. The fasting blood glucose and serum levels of MDA were significantly improved in the trial group who received vitamin B12. However, these changes did not reach a significant level compared to the placebo group. In this respect, further studies with larger sample sizes, different doses, and types of vitamin B12 will reveal additional evidence.Trial Registration: At  http://irct.ir/  as IRCT20120718010333N5 on December 25, 2019.

Combined biotin, folic acid, and vitamin B12 supplementation given during the transition period to dairy cows: Part I. Effects on lactation performance, energy and protein metabolism, and hormones

Biotin (B₈), folates (B₉), and vitamin B₁₂ (B₁₂) are involved and interrelated in several metabolic reactions related to energy and protein metabolism. We hypothesized that a low supply of one of the latter vitamins during the transition period would impair metabolic status. The purpose of this study was to evaluate the effect of B₈ supplementation on the response of lactation performance and selected energy and protein metabolites and hormones to a combined supplementation of B₉ and B₁₂ given to periparturient dairy cows, from d -21 to 21 relative to calving. A total of 32 multiparous Holstein cows housed in tie stalls were randomly assigned, according to their previous 305-d milk yield, to 8 incomplete blocks of 4 treatments: (1) a 2-mL weekly i.m. injection of saline (0.9% NaCl; B₈-/B₉B₁₂-); (2) 20 mg/d of dietary B₈ (unprotected from ruminal degradation) and 2-mL weekly i.m. injection of 0.9% NaCl (B₈+/B₉B₁₂-); (3) 2.6 g/d of dietary B₉ (unprotected) and 2-mL weekly i.m. injection of 10 mg of B₁₂ (B₈-/B₉B₁₂+); and (4) 20 mg/d of dietary B₈, 2.6 g/d of dietary B₉, and weekly i.m. injection of 10 mg of B₁₂ (B₈+/B₉B₁₂+) in a 2 × 2 factorial arrangement. Milk yield and dry matter intake were obtained daily and milk components weekly. Blood samples were taken weekly from d -21 to calving and 3 times per week from calving to 21 d following parturition. Prepartum plasma concentrations of glucose, insulin, nonesterified fatty acids (NEFA), β-hydroxybutyrate (BHB), and adiponectin were unaffected by treatments. Biotin, B₉, and B₁₂ supplements increased their respective concentrations in plasma and milk. Cows fed the B₈ supplement tended to have lower dry matter intake, but only cows in B₈+/B₉B₁₂- had greater plasma concentrations of NEFA compared with B₈-/B₉B₁₂-. Milk and total solid yields were greater by 13.5 and 13.9%, respectively, for B₈-/B₉B₁₂+ [45.5 (standard error, SE: 1.8) and 5.81 (0.22) kg/d, respectively] compared with B₈-/B₉B₁₂- [40.1 (1.9) and 5.10 (0.23) kg/d, respectively], but these effects were suppressed when combined with the B₈ supplement. Cows in the B₈-/B₉B₁₂+ group had decreased plasma insulin and tended to have increased NEFA concentrations, but postpartum plasma concentrations of glucose, BHB, leptin, and adiponectin were not affected. These cows also mobilized more body fat reserves, as suggested by a tendency to increased plasma NEFA and more milk total solids compared with B₈-/B₉B₁₂- cows. However, plasma concentrations of BHB and adiponectin were similar among treatments. This suggests that the B₉ and B₁₂ supplements enhanced efficiency of energy metabolism in early lactation cows. Folic acid and B₁₂ supplementation increased postpartum plasma Cys and homocysteine concentrations but did not affect plasma Met concentration, suggesting an upregulation of the transsulfuration pathway. In summary, our results showed that, under the current experimental conditions, increasing B₈ supply did not improve responses to the B₉ and B₁₂ supplementation.

Plasma Homocysteine Level Is Independently Associated With Conventional Atherogenic Lipid Profile and Remnant Cholesterol in Adults

Background

Homocysteine (Hcy) is an independent risk factor for cardiovascular disease, while mechanisms are unclear. Despite inconsistent and limited, epidemiological and experimental studies indicated that hyperhomocysteinemia (HHcy) affected lipid metabolism. This study aims to investigate the association of plasma Hcy with traditional lipid profiles and remnant cholesterol (RC) in Chinese adults.

Methods

In total, 7,898 subjects aged 20–79 years who underwent a physical examination at Beijing Chao-Yang Hospital in Beijing were included in this study. Fasting plasma total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein A1 (ApoA1), apolipoprotein B (ApoB), lipoprotein (a) [Lp(a)], Hcy, and other metabolic risk factors were measured by routine automated laboratory methods. RC was calculated as TC minus HDL-C and LDL-C. The linear regression model and logistic regression model were used to assess the relationship between Hcy and lipids after adjusting potential confounders.

Results

Of the subjects, the median level of plasma Hcy was 13.0 μmol/L and 32.3% had HHcy. Plasma Hcy was negatively associated with HDL-C, ApoA1, and Lp(a) and positively associated with TG levels after adjusting age, sex, body mass index, blood pressure, alanine transaminase, aspartate transaminase, creatinine, uric acid, and glucose. HHcy significantly increased the risk of low HDL-C [odds ratio (OR) 1.26; 95%CI (1.11–1.44); p &lt; 0.001]. The net mediation effects of ApoA1 on the relationship between Hcy and HDL-C before and after adjusting confounders were 46.9 and 30.6%, respectively. More interestingly, the RC level was significantly elevated in subjects with HHcy after adjusting other influencing factors (p = 0.025). Hcy presented a positive correlation with RC levels after adjusting the above confounding factors (β = 0.073, p = 0.004), and the correlation was still significant even after controlling other lipids, including TG, LDL-C, HDL-C, ApoA1, ApoB, and Lp(a).

Conclusion

Our study showed that plasma Hcy was not only significantly associated with conventional atherogenic lipids but also independently correlated with RC levels beyond other lipids after controlling potential confounders. This finding proposes that identifying Hcy-related dyslipidemia risk, both traditional lipids and RC residual risk, is clinically relevant as we usher in a new era of targeting Hcy-lowering therapies to fight against dyslipidemia or even cardiovascular disease.

Serum vitamin B12 levels and glycemic fluctuation in patients with type 2 diabetes mellitus

PURPOSE

The aim of the study was to explore the correlation between serum vitamin B12 levels and glycemic fluctuation in patients with type 2 diabetes mellitus (T2DM).

METHODS

This study included 202 T2DM patients in whom blood glucose levels were recorded using a continuous glucose monitoring system retrospectively. Glycemic fluctuation was determined using the average daily risk range (ADRR), a diabetes-specific measure of the risk for hyper- and hypoglycemia.

RESULTS

Serum vitamin B12 levels were higher in T2DM patients with wider glycemic fluctuations than in those with minor glycemic fluctuations (p < 0.001). We observed a positive correlation between serum vitamin B12 levels and ADRR in both T2DM patients who received and did not receive metformin therapy (r = 0.388, p < 0.001 and r = 0.280, p = 0.004, respectively). Multiple linear regression analysis showed that serum vitamin B12 levels were independently correlated with ADRR in T2DM patients who received and did not receive metformin therapy (beta = 0.367, p < 0.001 and beta = 0.410, p < 0.001, respectively).

CONCLUSIONS

Serum vitamin B12 levels are correlated with glycemic fluctuation in patients with T2DM and may serve as an underlying useful biomarker of glycemic fluctuation in T2DM patients, treated with or without metformin therapy.

Early supplementation of folate and vitamin B12 improves insulin resistance in intrauterine growth retardation rats

BACKGROUND

Insulin sensitivity is changed during the neonatal period in small for gestational age (SGA) infants. Yet, the interventional strategies are still limited. We aimed to investigate the effects of supplementation with high folate and vitamin B12 diets in the early postnatal period on the changes in insulin sensitivity in an intrauterine growth retardation (IUGR) rat model.

METHODS

IUGR rat model was established by both low-protein diet feeding and daily diet restriction. High folate and vitamin B12 diet was supplied in IUGR as nutritional interventional group (IUGR-I), otherwise, the non-intervened IUGR group (IUGR-NI). In this study, male rats were studied in order to avoid hormonal and gender influence. At 21, 60 and 120 days, fasting plasma glucose, insulin, triglyceride, cholesterol, and homocysteine levels were measured among the control, IUGR-I, and IUGR-NI groups. Pearson analysis was used to evaluate the correlation between homocysteine and fasting blood glucose, insulin, HOMA-IR, triglyceride, and cholesterol levels.

RESULTS

We established IUGR rat model by both low protein and restricted diet feeding during pregnancy and the incidence of IUGR pups was 93.33%. There was no difference in fasting glucose, insulin, HOMA-IR, triglyceride and cholesterol levels between the control, the IUGR-NI and the IUGR-I group at day 21. At day 60, insulin, HOMA-IR and triglyceride levels in the IUGR-I group were remarkably lower than those in the IUGR-NI group, but still higher than those in the control group (F=38.34, P=0.02; F=49.48, P=0.02; F=17.93, P<0.001, respectively). At day 120, glucose, insulin, HOMA-IR and Hcy levels in the IUGR-I group were obviously lower than those in the IUGR-NI group, although still higher than those in the control group (F=21.60, P<0.001; F=164.46, P<0.001; F=75.15, P<0.001; F=35.46, P<0.001, respectively). There were no significant differences in triglyceride and cholesterol levels between the IUGR-I group and the control group at day 120. At 120-day, homocysteine in IUGR-I group was highly positively correlated with fasting glucose and HOMA-IR (r=0.863, P=0.006; r=0.725, P=0.042, respectively); Only homocysteine was positively correlated with fasting glucose in IUGR-NI group (r=0.721, P=0.044).

CONCLUSIONS

Early supplementation of folate and vitamin B12 improved insulin resistance and lipid levels in IUGR rats to some extent, along with decreasing homocysteine levels, but not enough to completely repair glucose and lipid metabolism.

Cobalamin Intake and Related Biomarkers: Examining Associations With Mortality Risk Among Adults With Type 2 Diabetes in NHANES

OBJECTIVE

Despite that periodical monitoring of cobalamin (vitamin B12) in metformin-treated patients with diabetes is recommended, cobalamin-associated mortality benefits or risks remain unclear. We investigated the association between cobalamin intake and related biomarkers and mortality risk in adults with diabetes using metformin or not.

RESEARCH DESIGN AND METHODS

This study included 3,277 adults with type 2 diabetes from the National Health and Nutrition Examination Survey (NHANES) and followed up until 31 December 2015. Weighted Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% CIs for mortality risk.

RESULTS

Among 3,277 participants, 865 all-cause deaths occurred during a median follow-up of 7.02 years. There was no robust relationship between all-cause mortality and serum cobalamin or intake of foods or cobalamin supplements, regardless of metformin treatment (each P ≥ 0.120). The doubling of methylmalonic acid (MMA), a cobalamin-deficiency marker, was significantly associated with higher all-cause (HR 1.31 [95% CI 1.18-1.45], P < 0.001) and cardiac (HR 1.38 [95% CI 1.14-1.67], P = 0.001) mortality. Cobalamin sensitivity was assessed by the combination of binary B12low/high and MMAlow/high (cutoff values: cobalamin 400 pg/mL, MMA 250 nmol/L). Patients with decreased cobalamin sensitivity (MMAhighB12high) had the highest mortality risk. The multivariable-adjusted HRs (95% CIs) of all-cause mortality in MMAlowB12low, MMAlowB12high, MMAhighB12low, and MMAhighB12high groups were 1.00 (reference), 0.98 (0.75-1.28), 1.49 (1.16-1.92), and 1.96 (1.38-2.78), respectively. That association was especially significant in metformin nonusers.

CONCLUSIONS

Serum and dietary cobalamin were not associated with reduced mortality. Decreased cobalamin sensitivity was significantly associated with all-cause and cardiac mortality, particularly among metformin nonusers.

The Effects of Folic Acid Supplementation on Pro-inflammatory Mediators: a Systematic Review and Dose-Response Meta-Analysis of Randomized Controlled Trials

PURPOSE

Despite extensive research, findings regarding the effects of folic acid supplementation on inflammatory mediators have been controversial and inconclusive. This study therefore aimed to summarize the findings of all available clinical trials regarding the effects of folic acid supplementation on inflammatory biomarkers in adults.

METHODS

A systematic search was conducted of PubMed/MEDLINE, Scopus, Web of Science, EMBASE, and Google Scholar until April 2020. All randomized controlled trials that examined the influence of folic acid supplementation on C-reactive protein, interleukin 6 (IL-6), and tumor necrosis factor-α (TNF-α) were included. Pooled effect sizes were calculated based on the random effects model, and dose-response analysis was modeled by using a fractional polynomial model.

FINDINGS

In total, 18 randomized controlled trials involving 2286 participants were analyzed. Folic acid supplementation significantly reduced serum levels of C-reactive protein (mean difference [MD], -0.21 mg/L; 95% CI, -0.41 to -0.01; n = 16), TNF-α (MD, -14.88 pg/mL; 95% CI, -23.68 to -6.09; n = 10), and IL-6 (MD, -0.93 pg/mL; 95% CI, -1.72 to -0.14; n = 11). Subgroup analyses suggested a significant reduction at doses ≤5 mg/d and studies longer than 12 weeks in duration. A significant nonlinear association was also found between folic acid dosage (P_nonlinearity <0.001) and duration of administration (P_nonlinearity <0.001) with serum TNF-α levels.

IMPLICATIONS

This meta-analysis indicates the beneficial effects of folic acid supplementation on pro-inflammatory cytokines. Further studies with a longer duration of administration, higher doses, and larger sample sizes should be performed exclusively on patients with chronic inflammatory disorders to elucidate the favorable role of folate intake on inflammatory biomarkers. International Prospective Register of Systematic Reviews identifier: CRD42021249947.

Role of Vitamin B12 and Folate in Metabolic Syndrome

Metabolic syndrome (MS) is a collection of pathological metabolic conditions that includes insulin resistance, central or abdominal obesity, dyslipidemia, and hypertension. It affects large populations worldwide, and its prevalence is rising exponentially. There is no specific mechanism that leads to the development of MS. Proposed hypotheses range from visceral adiposity being a key factor to an increase in very-low-density lipoprotein and fatty acid synthesis as the primary cause of MS. Numerous pharmaceutical therapies are widely available in the market for the treatment of the individual components of MS. The relationship between MS and vitamin B complex supplementation, specifically folic acid and vitamin B12, has been a subject of investigation worldwide, with several trials reporting a positive impact with vitamin supplementation on MS.

In this study, an all-language literature search was conducted on Medline, Cochrane, Embase, and Google Scholar till September 2021. The following search strings and Medical Subject Headings (MeSH) terms were used: “Vitamin B12,” “Folate,” “Metabolic Syndrome,” and “Insulin Resistance.” We explored the literature on MS for its epidemiology, pathophysiology, newer treatment options, with a special focus on the effectiveness of supplementation with vitamins B9 and B12.

According to the literature, vitamin B12 and folate supplementation, along with a host of novel therapies, has a considerable positive impact on MS. These findings must be kept in mind while designing newer treatment protocols in the future.

The Relationship Between Folate, Vitamin B12 and Gestational Diabetes Mellitus With Proposed Mechanisms and Foetal Implications

The incidence of gestational diabetes mellitus (GDM) is rising, which warrants attention due to the associated complications during pregnancy and in the long term for both mother and offspring. Studies have suggested a relationship between maternal folate (vitamin B9) and vitamin B12 status and GDM risk. Seemingly the most problematic scenario occurs when there is B-vitamin imbalance, with high folate and low vitamin B12. This nutritional state can occur in vitamin B12 deficient women who exceed the recommended folic acid supplementation. However, the pathological mechanisms behind this relationship are currently unclear and are explored in this review article. A high folate/low B12 can lead to a functional folate deficiency through the methyl-trap phenomenon, impairing re-methylation of homocysteine and regeneration of folates for DNA synthesis and repair. Consequently elevated homocysteine concentration leads to endothelial dysfunction and oxidative stress. Vitamin B12 deficiency also leads to an impairment of the conversion of methylmalonyl-CoA to succinyl-CoA, which has been associated with insulin resistance. Insulin resistance is thought to contribute to the etiology of GDM. More studies are needed to confirm the impact of these and other mechanisms on disease development. However, it highlights a potential avenue for GDM risk modification through a vitamin B12 supplement and improvement of maternal metabolic health.

Nutraceutical Combinations in Hypercholesterolemia: Evidence from Randomized, Placebo-Controlled Clinical Trials

There is an increasing number of nutraceutical combinations (NCs) on the market for hypercholesterolemia, although clinical trials to verify their safety and efficacy are scarce. We selected fourteen randomized, placebo-controlled clinical trials (RCTs) on different lipid-lowering NCs in hypercholesterolemic subjects. We described each compound's mechanism of action and efficacy in the mixtures and summarized the clinical trials settings and NCs safety and efficacy results. Almost all NCs resulted efficient against hypercholesterolemia; only one reported no changes. Interestingly, red yeast rice (RYR) was present in eleven mixtures. It is not clear whether the lipid-lowering efficacy of these combinations derives mainly from the RYR component monacolin K "natural statin" single effect. Up to now, few RCTs have verified the efficacy of every single compound vs. NCs to evaluate possible additive or synergistic effects, probably due to the complexity and the high resources request. In conclusion, to manage the arising nutraceutical tide against hypercholesterolemia, it could be helpful to increase the number and robustness of clinical studies to verify the efficacy and safety of the new NCs.

Fruits and Vegetables in the Management of Underlying Conditions for COVID-19 High-Risk Groups

SARS-CoV-2 or COVID-19 is a novel coronavirus, which is the cause of the current pandemic with 107,411,561 infections and 2,351,195 death worldwide so far. There are multiple symptoms that are linked with the infection of COVID-19 such as coughing, shortness of breath, congestion together with fatigue, fever, loss of taste or smell, headaches, diarrhea, vomiting, and loss of appetite. The lack of or early stage of development of a cure for COVID-19 illness, there is need for insuring the best possible position of health to be able to fight the virus naturally through a robust immune system to limit severe complication. In this article, we have discussed the role of fruits and vegetables consumption to boost the immune system and major emphasis has been given to high risk group. We have taken into consideration a number of underlying conditions such as people with cardiovascular diseases, obesity, diabetes, chronic obstructive pulmonary disease, chronic kidney disease, hemoglobin disorder such as sickle cell disease, weakened immune system due to organ transplant. Furthermore, factors to improve the immune system, risks associated with quarantine and lifestyle and food handling during COVID-19 has been discussed.