Relationship of several serum folate forms with the risk of mortality: A prospective cohort study.

OBJECTIVE: We aim to examine the relation of several folate forms (5-methyltetrahydrofolate [5-mTHF], unmetabolized folic acid [UMFA], non-methyl folate, and MeFox [pyrazino-s-triazine derivative of 4α-hydroxy-5-methyltetrahydrofolate]) with the risk of mortality. METHODS: Using data from National Health and Nutrition Examination Survey 2011-2014, a total of 10,661 people with folate forms data were recruited. Death information was obtained from the National Death Index until 2015. Cox proportional hazards regression models were developed to evaluate the relationship between folate forms and mortality. RESULTS: During 2.99 years of follow-up, 344 (2.6%) deaths occurred. Overall, significantly higher risks of all-cause mortality were found in participants with higher level of serum 5-mTHF (≥51.3 nmol/L [quartile 4] vs. 23.9-51.3 nmol/L [quartile 2-3]; HR, 1.61; 95% CI: 1.03-2.53), UMFA (≥1.1 nmol/L [quartile 4] vs. <1.1 nmol/L [quartile 1-3]; HR, 1.55; 95% CI: 1.15-2.09), non-methyl folate (≥1.7 nmol/L [quartile 4] vs. 1.2-1.7 nmol/L [quartile 3]; HR, 1.62; 95% CI: 1.06-2.48), or MeFox (≥2.5 nmol/L [quartile 4] vs. <2.5 nmol/L [quartile 1-3]; HR, 1.54; 95% CI: 1.11-2.12). In addition, there was an increased risk of all-cause mortality for those with low level of serum 5-mTHF (<23.9 nmol/L [quartile 1] vs. 23.9-51.3 nmol/L [quartile 2-3]; HR, 1.66; 95% CI: 1.12-2.47). Most importantly, none of any folate forms significantly modified the association between other folate forms and mortality (all P for interactions >0.05). CONCLUSION: Higher levels of serum folate forms (5-mTHF, UMFA, non-methyl folate, and MeFox) were associated with higher risk of mortality while 5-mTHF insufficiency also showed a negative impact on mortality. Our findings emphasized the importance of monitoring the folate forms concentrations and may help counsel future related clinical trials.

Inpatient folate testing at an academic cancer center: single-year experience.

PURPOSE: The value of testing for folate deficiency has been scrutinized recently given low prevalence of deficiency with widespread dietary fortification. Numerous studies have shown folate testing to be low yield overall. However, the value of such testing in the inpatient cancer population has not been defined. METHODS: We queried all folate tests performed during 2017 at our center on admitted cancer patients. We used diagnosis codes and manual chart review to assess risk factors for folate deficiency. Descriptive statistics were used to summarize characteristics of patients undergoing folate testing, the frequency of vitamin B12 co-testing, and repeat folate testing. Fisher's exact test was used to compare the proportion of deficient vs. not deficient tests based on the presence of risk factors. A Cox proportional hazards model was fit to examine the association between folate deficiency and survival. RESULTS: In total, 937 patients had 1065 tests performed during 2017. Among all tests, 7.0% indicated folate deficiency. In patients who underwent two folate tests in a single hospitalization, 89% were deficient neither instance. Risk factors for folate deficiency were equally common in instances with deficient compared with replete testing (25.3 vs. 20.4%, P = 0.334). Folate deficiency was associated with higher risk for death (HR 1.49, 95% CI 1.10-2.03, P = 0.01). CONCLUSION: Folate deficiency was present in 7% of hospitalized cancer patients and associated with shorter overall survival. Repeat testing in the same patient over time was low yield. Traditional risk factors for folate deficiency do not appear to apply in this patient population.

Circulating Folate Concentrations and Risk of Peripheral Neuropathy and Mortality: A Retrospective Cohort Study in the U.K.

BACKGROUND: Folate deficiency may increase the risk of peripheral neuropathy but there is a paucity of data from large prospective studies examining this association. METHODS: Longitudinal analysis of electronic health records in The Health Improvement Network (THIN), a U.K. primary care database including 594,338 patients aged 18-70 years with a folate measurement and without a history of peripheral neuropathy. RESULTS: After a mean follow-up of 3.71 (standard deviation (SD) = 3.14) years, 1949 patients were diagnosed with peripheral neuropathy and 20,679 patients died. In those <40 years, compared to patients with folate ≥13.6 nmol/L, those with folate <6.8 (deficient) and 6.8-13.5 nmol/L (insufficient) had a hazard ratio (HR) for peripheral neuropathy of 1.83 (95% confidence intervals (CI) = 1.16-2.91) and 1.48 (95% CI = 1.04-2.08), respectively. There was no significant association between folate and peripheral neuropathy among those aged 41-70 years. Compared to patients with folate ≥ 13.6 nmol/L, folate <6.8 nmol/L was associated with a greater risk of death among all ages. CONCLUSION: Folate deficiency and insufficiency was associated with a greater risk of peripheral neuropathy among younger patients. This investigation should be replicated in other large datasets and it may be important to monitor peripheral neuropathy incidence after the introduction of mandatory folic acid fortification of flour in the U.K.

Reductions in child mortality by preventing spina bifida and anencephaly: Implications in achieving Target 3.2 of the Sustainable Development Goals in developing countries.

BACKGROUND: There is an opportunity to reduce child mortality by preventing folic acid-preventable spina bifida and anencephaly (FAP SBA) in developing countries. We estimated reductions in FAP SBA-associated child mortality in 69 countries with an immediate potential for mandatory fortification of wheat flour. METHODS: Using data from multiple sources, we estimated the percent reductions in neonatal, infant, and under-five mortality that would have occurred by preventing FAP SBA; and the contributions of these reductions toward each country's Sustainable Development Goals (SDG) for child mortality reduction. We used the combined prevalence of spina bifida and anencephaly in selected countries before fortification, and estimated preventable child mortality associated with FAP SBA, assuming 0.5 per 1,000 live births as minimum achievable prevalence from mandatory fortification. RESULTS: Annually, 56,785 live births with FAP SBA occurred in the 69 countries examined. Of these, about 49,680 (87%) would have resulted in deaths under age 5 years, and are preventable through mandatory folic acid fortification. On average, compared to current rates, prevention of FAP SBA would have reduced the neonatal, infant, and under-five mortality by 19% (95% uncertainty interval [UI]: 16-24%), 15% (UI: 13-17%), and 14%, (95% UI: 13-17%), respectively. Prevention of FAP SBA seemed to contribute toward achieving SDG on neonatal and under-five mortality in developing countries. CONCLUSIONS: Prevention of FAP SBA will lead to notable and immediate reductions in child mortality. Many countries have an opportunity to effectively move toward child mortality-related SDG targets with existing milling infrastructure for food fortification.

Folate deficiency in north Indian children undergoing maintenance chemotherapy for acute lymphoblastic leukemia-Implications and outcome.

BACKGROUND: Treatment-related toxicity and mortality are not uncommon during maintenance chemotherapy for childhood acute lymphoblastic leukemia (ALL), especially in the low- and middle-income countries (LMIC). Undernutrition and micronutrient deficiencies are commonly seen in children from LMICs undergoing treatment for ALL. The present study examines the prevalence and clinical implications of folate deficiency in north Indian children with ALL during the maintenance phase of treatment in view of prolonged antifolate treatment and high population prevalence of folate deficiency. PROCEDURES: Pre-cycle folate levels/deficiency as well as weight for age z-score and serum albumin level were determined and correlated with complications of treatment and mortality encountered during the maintenance phase of treatment. RESULTS: Twenty-nine of 52 children enrolled in the study had folate deficiency at some point during maintenance chemotherapy. Neutropenia (18 of 29 vs. 4 of 23; P = 0.002), thrombocytopenia (17 of 29 vs. 4 of 23; P = 0.005), febrile neutropenia (17 of 29 vs. 4 of 23; P = 0.005), and need for chemotherapy dose reduction (20 of 29 vs. 7 of 21; P = 0.01) were more common in folate-deficient children. Maintenance deaths were higher (8 of 29 vs. 1 of 23; P = 0.03) and survival lower (P = 0.02) in deficient children. In multivariate analysis, hypoalbuminemia (P = 0.02) and folate deficiency (P = 0.01) were associated with febrile neutropenia, and folate deficiency with maintenance deaths (P = 0.03). CONCLUSIONS: Folate deficiency was associated with treatment-related complications and adverse outcome in our patients. The risks and benefits of folate supplementation in deficient children during maintenance chemotherapy need to be explored with properly designed randomized studies in similar settings.

Intergenerational impact of paternal lifetime exposures to both folic acid deficiency and supplementation on reproductive outcomes and imprinted gene methylation.

STUDY QUESTION: Do paternal exposures to folic acid deficient (FD), and/or folic acid supplemented (FS) diets, throughout germ cell development adversely affect male germ cells and consequently offspring health outcomes? SUMMARY ANSWER: Male mice exposed over their lifetimes to both FD and FS diets showed decreased sperm counts and altered imprinted gene methylation with evidence of transmission of adverse effects to the offspring, including increased postnatal-preweaning mortality and variability in imprinted gene methylation. WHAT IS KNOWN ALREADY: There is increasing evidence that disruptions in male germ cell epigenetic reprogramming are associated with offspring abnormalities and intergenerational disease. The fetal period is the critical time of DNA methylation pattern acquisition for developing male germ cells and an adequate supply of methyl donors is required. In addition, DNA methylation patterns continue to be remodeled during postnatal spermatogenesis. Previous studies have shown that lifetime (prenatal and postnatal) folic acid deficiency can alter the sperm epigenome and increase the incidence of fetal morphological abnormalities. STUDY DESIGN, SIZE, DURATION: Female BALB/c mice (F0) were placed on one of four amino-acid defined diets for 4 weeks before pregnancy and throughout pregnancy and lactation: folic acid control (Ctrl; 2 mg/kg), 7-fold folic acid deficient (7FD; 0.3 mg/kg), 10-fold high FS (10FS, 20 mg/kg) or 20-fold high FS (20FS, 40 mg/kg) diets. F1 males were weaned to their respective prenatal diets to allow for diet exposure during all windows of germline epigenetic reprogramming: the erasure, re-establishment and maintenance phases. PARTICIPANTS/MATERIALS, SETTINGS, METHODS: F0 females were mated with chow-fed males to produce F1 litters whose germ cells were exposed to the diets throughout embryonic development. F1 males were subsequently mated with chow-fed female mice. Two F2 litters, unexposed to the experimental diets, were generated from each F1 male; one litter was collected at embryonic day (E)18.5 and one delivered and followed postnatally. DNA methylation at a global level and at the differentially methylated regions of imprinted genes (H19, Imprinted Maternally Expressed Transcript (Non-Protein Coding)-H19, Small Nuclear Ribonucleoprotein Polypeptide N-Snrpn, KCNQ1 Opposite Strand/Antisense Transcript 1 (Non-Protein Coding)-Kcnq1ot1, Paternally Expressed Gene 1-Peg1 and Paternally Expressed Gene 3-Peg3) was assessed by luminometric methylation analysis and bisulfite pyrosequencing, respectively, in F1 sperm, F2 E18.5 placenta and F2 E18.5 brain cortex. MAIN RESULTS AND THE ROLE OF CHANCE: F1 males exhibited lower sperm counts following lifetime exposure to both folic acid deficiency and the highest dose of folic acid supplementation (20FS), (both P < 0.05). Post-implantation losses were increased amongst F2 E18.5 day litters from 20FS exposed F1 males (P < 0.05). F2 litters derived from both 7FD and 20FS exposed F1 males had significantly higher postnatal-preweaning pup death (both P < 0.05). Sperm from 10FS exposed males had increased variance in methylation across imprinted gene H19, P < 0.05; increased variance at a few sites within H19 was also found for the 7FD and 20FS groups (P < 0.05). While the 20FS diet resulted in inter-individual alterations in methylation across the imprinted genes Snrpn and Peg3 in F2 E18.5 placenta, ≥50% of individual sites tested in Peg1 and/or Peg3 were affected in the 7FD and 10FS groups. Inter-individual alterations in Peg1 methylation were found in F2 E18.5 day 10FS group brain cortex (P < 0.05). LARGE SCALE DATA: Not applicable. LIMITATIONS REASONS FOR CAUTION: The cause of the increase in postnatal-preweaning mortality was not investigated post-mortem. Further studies are required to understand the mechanisms underlying the adverse effects of folic acid deficiency and supplementation on developing male germ cells. Genome-wide DNA and histone methylome studies as well as gene expression studies are required to better understand the links between folic acid exposures, an altered germ cell epigenome and offspring outcomes. WIDER IMPLICATIONS OF THE FINDINGS: The findings of this study provide further support for paternally transmitted environmental effects. The results indicate that both folic acid deficiency and high dose supplementation can be detrimental to germ cell development and reproductive fitness, in part by altering DNA methylation in sperm. STUDY FUNDING AND COMPETING INTERESTS: This study was supported by a grant to J.M.T. from the Canadian Institutes of Health Research (CIHR #89944). The authors declare they have no conflicts of interest.

B-Vitamin Serum Concentrations Predicting Long-Term Overall and Stroke-Free Survival after Carotid Endarterectomy.

BACKGROUND: Both deficiency and, according to recent reports, excess of vitamin B12 (B12) are associated with increased mortality. Thus, it is difficult to estimate the effect of B12 on overall survival, which also depends on folate (FA) in homocysteine lowering. This study aimed to assess FA and B12 serum concentrations associated with long-term survival of vascular surgery patients by means of a prognostic index (PI). METHODS: This single-center, prospective cohort study comprised 485 consecutive carotid surgery patients. B-vitamin baseline concentrations of B12 and FA were used to compute a PI for postoperative overall survival from January 2003 to January 2012 (mean observation period 102.3 months). RESULTS: Increasing B12 serum concentrations showed a nonlinear association with overall survival (P = .033). A B vitamin-based PI significantly predicted overall (hazard ratio [HR] per standard deviation = 1.97, confidence interval [CI] 1.37-2.82; P < .001), cardiovascular (HR = 3.03, CI 1.78-5.14; P < .001), and stroke-free survival (HR = 2.20, CI 1.22-3.98; P = .009), and revealed that the highest adverse event-free survival was predicted by high FA (16.3 ± 12.9 ng/mL) but only moderate B12 (360.3 ± 156.0 pmol/L) baseline concentrations. CONCLUSIONS: Prediction of increased long-term overall, cardiovascular, and stroke-free survival is based on high FA but only moderate B12 serum concentrations. Excessive B12 concentrations might harbor a potential harm and are no requisite for low homocysteine concentrations. The association between B vitamins and survival might serve either as a tool for risk stratification or, if causative, as effective therapy, if optimal dosing of B vitamins is provided and on-treatment concentrations, including homocysteine and renal functions, are closely monitored.

Vitamin B12 and folate deficiency in chronic heart failure.

OBJECTIVE: To determine the prevalence, clinical correlates and the effects on outcome of vitamin B12 and folic acid levels in patients with chronic heart failure (HF). METHODS: We studied an international pooled cohort comprising 610 patients with chronic HF. The main outcome measure was all-cause mortality. RESULTS: Mean age of the patients was 68±12 years and median serum N-terminal prohormone brain natriuretic peptide level was 1801 pg/mL (IQR 705-4335). Thirteen per cent of the patients had an LVEF >45%. Vitamin B12 deficiency (serum level <200 pg/mL), folate deficiency (serum level <4.0 ng/mL) and iron deficiency (serum ferritin level <100 µg/L, or 100-299 µg/L with a transferrin saturation <20%) were present in 5%, 4% and 58% of the patients, respectively. No significant correlation between mean corpuscular volume and vitamin B12, folic acid or ferritin levels was observed. Lower folate levels were associated with an impaired health-related quality of life (p=0.029). During a median follow-up of 2.10 years (1.31-3.60 years), 254 subjects died. In multivariable proportional hazard models, vitamin B12 and folic acid levels were not associated with prognosis. CONCLUSIONS: Vitamin B12 and folate deficiency are relatively rare in patients with chronic HF. Since no significant association was observed between mean corpuscular volume and neither vitamin B12 nor folic acid levels, this cellular index should be used with caution in the differential diagnosis of anaemia in patients with chronic HF. In contrast to iron deficiency, vitamin B12 and folic acid levels were not related to prognosis.

No increased mortality risk in older persons with unexplained anaemia.

BACKGROUND: in older persons, anaemia is associated with a number of unfavourable outcomes. In approximately 30% of older persons with anaemia, the cause of the anaemia is unexplained. We assessed the clinical differences between subjects with explained and unexplained anaemia and investigated whether these subjects have different mortality patterns compared with subjects without anaemia. DESIGN: observational prospective follow-up study. SETTING: the Leiden 85-plus study. PARTICIPANTS: four hundred and ninety-one persons aged 86 years. METHODS: the study population was divided in three groups: (i) no anaemia (reference group, n=377), (ii) explained anaemia (iron deficiency, folate deficiency, vitamin B12 deficiency, signs of myelodysplastic syndrome or renal failure, n=74) and (iii) unexplained anaemia, (n=40). Mortality risks were estimated with Cox-proportional hazard models. RESULTS: haemoglobin levels were significantly lower in subjects with explained anaemia than in subjects with unexplained anaemia (P<0.01). An increased risk for mortality was observed in subjects with explained anaemia [HR: 1.93 (95% CI: 1.47-2.52), P<0.001], but not in subjects with unexplained anaemia [HR: 1.19 (95% CI: 0.85-1.69), P=0.31]. Adjusted analyses (sex, co-morbidity, MMSE, institutionalised and smoking) did not change the observed associations for both explained and unexplained anaemic subjects. CONCLUSION: older subjects with unexplained anaemia had similar survival compared with non-anaemic subjects. Increased mortality risks were observed in subjects with explained anaemia compared with non-anaemic subjects.

Serum homocysteine and folate but not vitamin B12 are predictors of CHD mortality in older adults.

AIMS: The associations of serum levels of homocysteine (tHcy), vitamin B(12), and folate with risk of all-cause and coronary heat disease (CHD) mortality is controversial, and the evidence in older adults is limited. The aim of this study was to examine whether serum folate, vitamin B(12), and tHcy independently predict risk of CHD-related and all-cause mortality in older adults. METHODS AND RESULTS: Serum concentrations of folate, vitamin B(12), and tHcy were determined from blood samples obtained from 3010 Blue Mountains Eye Study participants (1997-99), aged ≥55 years. CHD and all-cause mortality was confirmed using the Australian National Death Index. RESULTS: Persons in the highest quartile of serum tHcy had increased risk of CHD mortality compared to those in the lowest quartile (multivariable-adjusted hazard ratio, HR, 2.45, 95% CI 1.30-4.62). A significant continuous association was observed between serum tHcy and CHD mortality (HR per SD ( = 4.8 µmol/l) increase in serum tHcy 1.25, 95% CI 1.08-1.45), after multivariable-adjustment. A significant association between folate deficiency and CHD-mortality was found (multivariable-adjusted HR 1.53, 95% CI 1.01-2.29). Hyperhomocysteinaemia (>15 µmol/l) was a significant predictor of all-cause mortality (multivariable-adjusted HR 1.47, 95% CI 1.18-1.83). A significant interaction was observed between hyperhomocysteinaemia and folate deficiency for all-cause and CHD mortality (p for interaction = 0.03 and p for interaction = 0.05, respectively). CONCLUSION: Serum tHcy and folate were independent predictors of CHD and all-cause mortality, while vitamin B(12) was not associated. As raised tHcy levels and folate deficiency are associated with poorer lifestyle, changes to a more healthful lifestyle among older adults may minimize the adverse vascular effects of elevated tHcy.

An analysis of anemia and pregnancy-related maternal mortality.

The relationship of anemia as a risk factor for maternal mortality was analyzed by using cross-sectional, longitudinal and case-control studies because randomized trials were not available for analysis. The following six methods of estimation of mortality risk were adopted: 1) the correlation of maternal mortality rates with maternal anemia prevalence derived from national statistics; 2) the proportion of maternal deaths attributable to anemia; 3) the proportion of anemic women who die; 4) population-attributable risk of maternal mortality due to anemia; 5) adolescence as a risk factor for anemia-related mortality; and 6) causes of anemia associated with maternal mortality. The average estimates for all-cause anemia attributable mortality (both direct and indirect) were 6.37, 7.26 and 3.0% for Africa, Asia and Latin America, respectively. Case fatality rates, mainly for hospital studies, varied from <1% to >50%. The relative risk of mortality associated with moderate anemia (hemoglobin 40-80 g/L) was 1.35 [95% confidence interval (CI): 0.92-2.00] and for severe anemia (<47 g/L) was 3.51 (95% CI: 2.05-6.00). Population-attributable risk estimates can be defended on the basis of the strong association between severe anemia and maternal mortality but not for mild or moderate anemia. In holoendemic malarious areas with a 5% severe anemia prevalence (hemoglobin <70 g/L), it was estimated that in primigravidae, there would be 9 severe-malaria anemia-related deaths and 41 nonmalarial anemia-related deaths (mostly nutritional) per 100,000 live births. The iron deficiency component of these is unknown.

The dietary requirement of young rainbow trout (Oncorhynchus mykiss) for folic acid.

We sought to determine the dietary folic acid requirement of young rainbow trout using growth indices supported by measurements of tissue folate concentrations. The investigation was conducted with purified diets that had, by assay, basal folic acid levels of 0.08 and 0.16 mg/kg in the first and second, respectively, of two experiments. Each experiment was started with fry (initial mean weight, 1.4 and 2.8 g/fish in Experiments 1 and 2, respectively) and was conducted at a water temperature of 15 degrees C. Experiment 1 lasted 18 wk and Experiment 2 lasted 16 wk. Recovery tests (of 8 wk duration, performed on fish fed the unsupplemented diet) and pair-feeding showed that the unsupplemented diet led to a folate-specific deficiency condition in which the main hematological abnormality was the appearance of misshapen nuclei in a small proportion (2.3%) of erythrocytes. Dietary requirements were shown not to exceed 0.3 and 0.6 mg folic acid/kg (17 and 33 micrograms/MJ digestible energy) for optimizing survival and growth indices, respectively. We conclude that the dietary folate requirement of the trout is comparable to that of other vertebrates for the purpose of achieving maximal weight gain.

Reduction of duration and severity of megimide seizures in rats on a folic acid deficient diet.

Folic acid deficient diet reduces the duration and severity of intravenous megimide seizures in the rat after 6 months of diet. Plasma and serum folate levels are strongly reduced after that period. The difference between Lactobacillus casei and Streptococcus faecalis activity in brain show a slight, but not significant, decrease after 12 months of diet.