Folate and vitamin B 12 : friendly or enemy nutrients for the elderly: Symposium on ‘Micronutrients through the life cycle’

Low vitamin B12 blood levels in sickle cell disease: Data from a large cohort study in Tanzania

Sickle cell disease (SCD) is associated with high rates of undernutrition and stunting. Undernutrition in combination with chronic haemolysis may lead to deficiencies in micronutrients necessary for erythropoiesis. Here we examined selected levels of ferritin, vitamins B2 , B6 , B9 and B12 , and vitamin C that were measured in blood samples from 820 SCD patients from Tanzania with no history of hospital admission, infections or painful episodes in the previous 30 days. We studied children (0-8 years), early adolescents (9-14 years), late adolescents (15-17 years) and adults (≥18 years). Severely low levels of vitamin B12 were observed across the four age groups. Despite the lowered vitamin B12 concentrations, total homocysteine concentrations were normal across both genders in all age groups. We found no significant gender-related differences between the other measured micronutrients. In this large SCD population, spanning the whole life cycle, a low level of vitamin B12 was consistently found across both genders and all age groups. Given the pivotal role of vitamin B12 in cellular metabolism, particularly in erythropoiesis, more studies are required to unravel how to better detect clinically relevant vitamin B12 deficiency among SCD patients, and thus to identify more precisely those who need supplementation of vitamin B12 .

Vitamin B12 is associated negatively with anemia in older Chinese adults with a low dietary diversity level: evidence from the Healthy Ageing and Biomarkers Cohort Study (HABCS)

OBJECTIVE

The associations between plasma vitamin B12 level and anemia under different dietary patterns in elderly Chinese people are poorly understood. We aimed to examine the associations between plasma vitamin B12 levels and anemia under different dietary patterns in adults aged 65 years and older in nine longevity areas in China.

METHODS

A total of 2405 older adults completed a food frequency questionnaire at the same time as a face-to-face interview. The dietary diversity score (DDS) was assessed based on the food frequency questionnaire, with the low DDS group referring to participants with a DDS score ≤ 4 points. Vitamin B12 levels were divided into two groups of high (>295 pg/mL) and low (≤ 295 pg/mL) with the median used as the cut-off point. Sub-analyses were also performed on older adults divided into tertiles of vitamin B12 levels: low (< 277 pg/mL), medium (277-375 pg/mL) and high (> 375 pg/mL) to study the association of these levels with anemia.

RESULTS

Six hundred ninety-five (28.89%) of these people were diagnosed with anemia and had a mean age of 89.3 years. Higher vitamin B12 levels were associated with a decreased risk of anemia (multi-adjusted OR, 0.59, [95% CI, 0.45 ~ 0.77] P < 0.001) in older adults with a low DDS, whereas no significant association between vitamin B12 levels and anemia was found in older adults with a high DDS in a full-model after adjustment for various confounding factors (multi-adjusted OR, 0.88, [95% CI, 0.65 ~ 1.19], P = 0.41).

CONCLUSION

The relationship between vitamin B12 levels and the prevalence of anemia was significant only when the level of dietary diversity in the older adults was relatively low. The dietary structure of the population should be taken into consideration in combination in order to effectively improve anemia status by supplementing vitamin B12.

Elderly Patient With Hematological and Neurological Manifestations of Undetermined Origin: A Diagnostic Dilemma of Pernicious Anemia

Pernicious anemia (PA) is a chronic inflammatory destructive disease of parietal cells of predominantly the gastric fundus. It leads to vitamin B12 (cobalamin) deficiency secondary to a deficiency of intrinsic factors. Despite the medical advances nowadays, diagnosing PA can be challenging. This report highlights a neglected case of PA with ongoing subacute combined degeneration of the cord (SCDS) in an elderly patient. An 86-year-old lady with multiple comorbidities was referred to the hematology outpatient clinic for refractory anemia for the last two months. At first, her general practitioner (GP) treated her as a case of anemia of chronic disease but without improvement. Her initial clinical assessment revealed hematological and neurological manifestations of undetermined origin, including global weakness, hypertonia, and hyperreflexia with sensory deficits, especially in the lower limbs. On investigation, the hemoglobin level was 9 g/dL with high indirect bilirubinemia and lactate dehydrogenase (LDH). Despite the normal mean corpuscular volume (MCV) and peripheral blood smear, positive anti-intrinsic factor and parietal cell antibodies tests were subsequently reported, suggesting the diagnosis of PA. As a result, she was commenced on lifelong parenteral cobalamin replacement therapy. On follow-up visits of three months, she illustrated a clinical recovery in fatigability and paranesthesia. As expected, the laboratory parameters revealed a rise in hemoglobin level (11 g/dL) and serum vitamin B12 (418 pg/mL). However, she remained bedridden with spastic limbs. Clinicians should have a high index of suspicion since PA is a rare disease with variable clinical presentations. The optimal management approach is by a multidisciplinary care team of internists, neurologists, gastroenterologists, and hematologists.

Brain Trauma and the Secondary Cascade in Humans: Review of the Potential Role of Vitamins in Reparative Processes and Functional Outcome

An estimated sixty-nine million people sustain a traumatic brain injury each year. Trauma to the brain causes the primary insult and initiates a secondary biochemical cascade as part of the immune and reparative response to injury. The secondary cascade, although a normal physiological response, may also contribute to ongoing neuroinflammation, oxidative stress and axonal injury, continuing in some cases years after the initial insult. In this review, we explain some of the biochemical mechanisms of the secondary cascade and their potential deleterious effects on healthy neurons including secondary cell death. The second part of the review focuses on the role of micronutrients to neural mechanisms and their potential reparative effects with regards to the secondary cascade after brain injury. The biochemical response to injury, hypermetabolism and excessive renal clearance of nutrients after injury increases the demand for most vitamins. Currently, most research in the area has shown positive outcomes of vitamin supplementation after brain injury, although predominantly in animal (murine) models. There is a pressing need for more research in this area with human participants because vitamin supplementation post-trauma is a potential cost-effective adjunct to other clinical and therapeutic treatments. Importantly, traumatic brain injury should be considered a lifelong process and better evaluated across the lifespan of individuals who experience brain injury.

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

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

Folate content of a staple food increased by fermentation of a cereal using selected folate-producing microorganisms

Folate deficiencies are widespread in Africa due to predominantly cereal-based diets. The objective of this work was to test the feasibility of using folate-producing microorganisms to increase folate content of tef injera, a traditional Ethiopian fermented staple food. To this end, a strain of Lactobacillus plantarum previously isolated from fermented tef batter and a commercial Saccharomyces cerevisiae were used alone and in combination to prepare injera. Ten successive fermentations using backslopping from the fermented batter prepared with L. plantarum inoculation were performed to mimic the traditional backslopping. The highest folate content was obtained with S. cerevisiae (53.5 μg/100 ​g fresh material). All the combinations were efficient and could cover up to 22 % of the recommended nutrient intakes. All injera prepared with selected inoculums were preferred by sensory panelists to the traditional one. This work demonstrates the possibility to increase folate intake using folate-producing microorganisms in the conditions normally encountered in households.

The safety of commonly used vitamins and minerals

Dietary supplements are the most common type of complementary medicine in Australia, reportedly used by 47% of the population. Vitamins and minerals are particularly popular

Like all medicines, supplements can cause potential harms such as adverse reactions, drug interactions, monetary cost, delay of more effective therapy, false hope, and increased medication burden

Although most vitamins and minerals are available for open sale, many are subject to legal restrictions as scheduled medicines, depending on the dose

Consumers are at risk of overdose when the same ingredient is present in multiple products

Health professionals can assist consumers by discussing the potential benefits and harms of vitamins and minerals and assisting them to find authoritative information

Adverse events with vitamins and minerals should be reported to the Therapeutic Goods Administration

Comparison of Micronutrient Intervention Strategies in Ghana and Benin to Cover Micronutrient Needs: Simulation of Bene-Fits and Risks in Women of Reproductive Age

Overlapping micronutrient interventions might increase the risk of excessive micronutrient intake, with potentially adverse health effects. To evaluate how strategies currently implemented in Benin and Ghana contribute to micronutrient intake in women of reproductive age (WRA), and to assess the risk for excess intakes, scenarios of basic rural and urban diets were built, and different on-going interventions were added. We estimated micronutrient intakes for all different scenarios. Four types of intervention were included in the scenarios: fortification, biofortification, supplementation and use of locally available nutrient-rich foods. Basic diets contributed poorly to daily micronutrient intake in WRA. Fortification of oil and salt were essential to reach daily requirements for vitamin A and iodine, while fortified flour contributed less. Biofortified products could make an important contribution to the coverage of vitamin A needs, while they were not sufficient to cover the needs of WRA. Iron and folic acid supplementation was a major contributor in the intake of iron and folate, but only in pregnant and lactating women. Risk of excess were found for three micronutrients (vitamin A, folic acid and niacin) in specific contexts, with excess only coming from voluntary fortified food, supplementation and the simultaneous overlap of several interventions. Better regulation and control of fortification and targeting of supplementation could avoid excess intakes.

Lactobacillus plantarum P2R3FA Isolated from Traditional Cereal-Based Fermented Food Increase Folate Status in Deficient Rats

Folate deficiencies are widespread around the world. Promoting consumption of folate-rich foods could be a sustainable option to alleviate this problem. However, these foods are not always available. Cereals, being a staple food, could contribute to folate intake. They are fermented prior to consumption in many African countries, and fermentation can modify the folate content. In Ethiopia, injera is a widely consumed fermented flat bread. The main drivers of its fermentation are lactic acid bacteria (LAB). The aim of this work was to isolate and identify folate-producing LAB from injera fermented dough and to evaluate their ability to increase folate status after depletion in a rat model. Among the 162 strains isolated from 60 different fermentations, 19 were able to grow on a folate-free culture medium and produced 1 to 43 µg/L (24 h, 30 °C incubation). The four highest folate producers belonged to the Lactobacillus plantarum species. The most productive strain was able to enhance folate status after depletion in a rat model, despite the relatively low folate content of the feed supplemented with the strain. Folate-producing L. plantarum strain has potential use as a commercial starter in injera production.

Dietary Micronutrients Intake Status among Chinese Elderly People Living at Home: Data from CNNHS 2010-2012

The aim of this study was to examine the status of usual dietary micronutrient intakes among Chinese elderly living at home. The data was based on China National Nutrition and Health Survey (CNNHS) 2010-2012. We analyzed data from the participants aged 60-year-old and more (n = 16,612) living at home, who provided dietary data on three days 24 h dietary survey combining with the household weighing method. The means and distribution percentiles for usual intakes of dietary micronutrients were estimated using the Multiple Source Method (MSM). The prevalence of inadequacy for the selected micronutrients was expressed using the proportion of individuals with usual intakes below the Estimated Average Requirement (EAR). For vitamin E, sodium and potassium, the means and the distribution of intakes were compared to the Adequate Intake (AI) level. Usual dietary intakes of most micronutrients were inadequate in the participants, especially folate, calcium, vitamin B6 and vitamin B2, with the prevalence of inadequacy more than 90%. However, dietary sodium intake was extremely high with an average usual intake of 4702 mg/day. The usual dietary intakes of all selected micronutrients in old males were higher than females, and the prevalence of inadequacy of most micronutrients was higher in old women (p < 0.01). The subjects aged 60-74 years tended to have higher usual dietary micronutrient intakes and lower prevalence of inadequate micronutrients than those aged 75 years and over (p < 0.01). Higher usual dietary intakes and lower prevalence of inadequacy of most micronutrients were found in the elderly living in the southern region (p < 0.01). The average usual intakes of most micronutrients declined with socioeconomic status. The prevalence of inadequate vitamin A, B2, C, calcium and selenium below EAR increased with socioeconomic status (p < 0.01, p for trend < 0.01). Thus, essential micronutrients insufficient intake is a public health concern among Chinese community-dwelling old population, especially the females, older people, the elderly in undeveloped areas or living in northern regions. Nutrition education and appropriate approach should be undertaken to address these problems.

Development and Validation of a Rapid High-Performance Liquid Chromatography⁻Tandem Mass Spectrometric Method for Determination of Folic Acid in Human Plasma

There are health concerns associated with increased folic acid intake from fortified food and supplements. Existing analytical methods, however, which can be employed to carry out epidemiological and bioavailability studies for folic acid involve laborious sample preparation and/or lengthy chromatographic analysis. In this paper we describe a simple, rapid, and sensitive high-performance liquid chromatography–electrospray ionisation-tandem mass spectrometry (HPLC–ESI-MS/MS) method for determination of unmetabolised folic acid in human plasma using folic acid-d4 as an internal standard. The method required only a simple sample preparation step of protein precipitation and had a total run time of 3.5 min, which is the shortest run time reported to date for HPLC–MS/MS method employed for quantifying folic acid in plasma. The analytes were separated on a C18 column (3 µm; 50 × 3.00 mm) using an isocratic mobile phase consisting of ammonium acetate (1 mM)-acetic acid-acetonitrile (9.9:0.1:90, v/v/v). The method was fully validated in terms of accuracy, precision, linearity, selectivity, recovery, matrix effect, and stability. The short run time and the minimal sample preparation makes the method a valuable tool for performing high-throughput analyses. To demonstrate the applicability of the method in real conditions, it was applied successfully in a bioavailability study for the determination of unmetabolised folic acid levels in vivo in human plasma after oral administration of folic acid.

Aging and computational systems biology

Aging research is undergoing a paradigm shift, which has led to new and innovative methods of exploring this complex phenomenon. The systems biology approach endeavors to understand biological systems in a holistic manner, by taking account of intrinsic interactions, while also attempting to account for the impact of external inputs, such as diet. A key technique employed in systems biology is computational modeling, which involves mathematically describing and simulating the dynamics of biological systems. Although a large number of computational models have been developed in recent years, these models have focused on various discrete components of the aging process, and to date no model has succeeded in completely representing the full scope of aging. Combining existing models or developing new models may help to address this need and in so doing could help achieve an improved understanding of the intrinsic mechanisms which underpin aging.

Examining the Association between Vitamin B12 Deficiency and Dementia in High-Risk Hospitalized Patients

OBJECTIVES

To explore the association between vitamin B12 deficiency and dementia in patients at high risk for vitamin B12 deficiency.

DESIGN

Chart review.

SETTING

Emergency, critical care/ trauma, neurology, medicine, and rehabilitation units of two hospitals in Southwestern Ontario, Canada.

PARTICIPANTS

Adult patients (n = 666) admitted from 2010 to 2012. Data collection included: reason for admission, gender, age, clinical signs and symptoms of B12 deficiency, serum B12 concentration, and B12 supplementation. Patients with dementia were identified based on their medication profile and medical history. Vitamin B12 deficiency (pmol/L) was defined as serum B12 concentration <148; marginal deficiency: ≥148-220 and adequate >220. Comparisons between B12-deficient patients with and without dementia were examined using parametric and non-parametric tests.

RESULTS

Serum B12 values were available for 60% (399/666) of the patients, of whom 4% (16/399) were B12-deficient and 14% (57/399) were marginally deficient. Patients with dementia were not more likely to be B12-deficient or marginally deficient [21% (26/121)] compared to those with no dementia [17% (47/278), p=0.27)]. Based on documentation, 34% (25/73) of the B12-deficient and marginally-deficient patients did not receive B12 supplementation, of whom 40% (10/25) had dementia.

CONCLUSION

In this sample of patients, there was no association between B12 deficiency and dementia. However, appropriate B12 screening protocols are necessary for high risk patient to identify deficiency and then receive B12 supplementation as needed.

Systematic review of adverse health outcomes associated with high serum or red blood cell folate concentrations

BACKGROUND

To examine the relationship between reported high serum or red blood cell (RBC) folate status and adverse health outcomes.

METHODS

We systematically searched PubMed/Medline and EMBASE (to May 2013), with no limits by study type, country or population, to identify studies reporting high folate concentrations in association with adverse health outcomes. Two reviewers screened studies and extracted data. Study quality was assessed.

RESULTS

We included 51 articles, representing 46 studies and 71 847 participants. Quantiles were used by 96% of studies to identify high folate concentrations. Eighty-three percent of serum folate and 50% of RBC folate studies reported a high folate cutoff that corresponded with a clinically normal concentration. Increasing values of reported high folate concentration did not demonstrate a consistent association with risk of adverse health outcomes. Overall, reported high folate concentrations appeared to be associated with a decreased risk of adverse health outcomes, though substantial methodological heterogeneity precluded complex analyses.

CONCLUSIONS

Our interpretation was complicated by methodological variability. High folate cutoffs varied and often corresponded with normal or desirable blood concentrations. In general, a negative association appeared to exist between reported high folate status and adverse health outcomes. Consistent methods and definitions are needed to examine high folate status and ultimately inform public health interventions.

Vitamin B₁₂-containing plant food sources for vegetarians

The usual dietary sources of Vitamin B₁₂ are animal-derived foods, although a few plant-based foods contain substantial amounts of Vitamin B₁₂. To prevent Vitamin B₁₂ deficiency in high-risk populations such as vegetarians, it is necessary to identify plant-derived foods that contain high levels of Vitamin B₁₂. A survey of naturally occurring plant-derived food sources with high Vitamin B₁₂ contents suggested that dried purple laver (nori) is the most suitable Vitamin B₁₂ source presently available for vegetarians. Furthermore, dried purple laver also contains high levels of other nutrients that are lacking in vegetarian diets, such as iron and n-3 polyunsaturated fatty acids. Dried purple laver is a natural plant product and it is suitable for most people in various vegetarian groups.

Potential effects of dietary folate supplementation on oral carcinogenesis, development and progression

Folates are associated with a variety of human health benefits, while folate deficiency has been identified as a potential risk factor for many health problems and cancers, due to its role in dysregulation of DNA synthesis, repair and methylation. The US Food and Drug Administration adopted requirements for folate fortification in some food products, which has resulted in an increase in mean dietary folate intake and a concomitant reduction in the incidence of adverse health effects associated with folate deficiency. This includes a significant reduction in the incidence of folate deficiency-associated birth defects, such as spina bifida.

Lactic acid bacteria producing B-group vitamins: a great potential for functional cereals products

Wheat contains various essential nutrients including the B group of vitamins. However, B group vitamins, normally present in cereals-derived products, are easily removed or destroyed during milling, food processing or cooking. Lactic acid bacteria (LAB) are widely used as starter cultures for the fermentation of a large variety of foods and can improve the safety, shelf life, nutritional value, flavor and overall quality of the fermented products. In this regard, the identification and application of strains delivering health-promoting compounds is a fascinating field. Besides their key role in food fermentations, several LAB found in the gastrointestinal tract of humans and animals are commercially used as probiotics and possess generally recognized as safe status. LAB are usually auxotrophic for several vitamins although certain strains of LAB have the capability to synthesize water-soluble vitamins such as those included in the B group. In recent years, a number of biotechnological processes have been explored to perform a more economical and sustainable vitamin production than that obtained via chemical synthesis. This review article will briefly report the current knowledge on lactic acid bacteria synthesis of vitamins B2, B11 and B12 and the potential strategies to increase B-group vitamin content in cereals-based products, where vitamins-producing LAB have been leading to the elaboration of novel fermented functional foods. In addition, the use of genetic strategies to increase vitamin production or to create novel vitamin-producing strains will be also discussed.

Cancer risk with folic acid supplements: a systematic review and meta-analysis

Objective To explore if there is an increased cancer risk associated with folic acid supplements given orally. Design Systematic review and meta-analysis of controlled studies of folic acid supplementation in humans reporting cancer incidence and/or cancer mortality. Studies on folic acid fortification of foods were not included. Data sources Cochrane Library, Medline, Embase and Centre of Reviews and Dissemination, clinical trial registries and hand-searching of key journals. Results From 4104 potential references, 19 studies contributed data to our meta-analyses, including 12 randomised controlled trials (RCTs). Meta-analysis of the 10 RCTs reporting overall cancer incidence (N=38 233) gave an RR of developing cancer in patients randomised to folic acid supplements of 1.07 (95% CI 1.00 to 1.14) compared to controls. Overall cancer incidence was not reported in the seven observational studies. Meta-analyses of six RCTs reporting prostate cancer incidence showed an RR of prostate cancer of 1.24 (95% CI 1.03 to 1.49) for the men receiving folic acid compared to controls. No significant difference in cancer incidence was shown between groups receiving folic acid and placebo/control group, for any other cancer type. Total cancer mortality was reported in six RCTs, and a meta-analysis of these did not show any significant difference in cancer mortality in folic acid supplemented groups compared to controls (RR 1.09, 95% CI 0.90 to 1.30). None of the observational studies addressed mortality. Conclusions A meta-analysis of 10 RCTs showed a borderline significant increase in frequency of overall cancer in the folic acid group compared to controls. Overall cancer incidence was not reported in the seven observational studies. Prostate cancer was the only cancer type found to be increased after folic acid supplementation (meta-analyses of six RCTs). Prospective studies of cancer development in populations where food is fortified with folic acid could indicate whether fortification similar to supplementation moderately increases prostate cancer risk.

Estimating the impact of mandatory folic acid fortification on the folic acid intake of Australian women of childbearing age

OBJECTIVE

The primary aim of this study was to estimate the impact of mandatory folic acid (FA) fortification of bread-making flour on the FA intake of Australian women of childbearing age (16-44 years). The secondary objective was to investigate the relationship between estimated FA intake and socio-economic status (SES) and age.

METHOD

Dietary modelling was used to estimate FA intake under four mandatory fortification scenarios--no supplement use, supplement use unrelated to FA intake, supplement use only among the highest consumers of bread, and increased supplement use. Data were obtained from the 1995 National Nutrition Survey for food intake patterns, the 2007 Victorian Population Health Survey for FA supplement use, and a marketplace survey.

RESULTS

It is estimated that the National Health and Medical Research Council (NHMRC) recommendation for an additional 400 μg/day [DOSAGE ERROR CORRECTED] FA will be achieved by a minimum of 3.9, 25.4, 21.7 and 30% of the target population under scenarios 1-4, respectively. The FA upper level of intake is exceeded by a maximum of 0.1, 1.7, 6.1 and 4.1% of the target population for scenarios 1-4, respectively. Conclusions : Mandatory FA fortification is not sufficient for the NHMRC recommendations for minimum and maximum intakes to be met by all of the target population under a number of plausible behaviour scenarios.

IMPLICATIONS

Targeted nutrition education campaigns are needed for SES and age sub-groups and research of this nature should be extended to other population groups. Monitoring and evaluation of this policy will be important to ensure appropriate FA intake.

Policy statement on folic acid and neural tube defects

It now recognized that the use of folate fortification and/or supplementation before initiation of pregnancy can impact the risk of the fetus developing a neural tube defect. This document serves to update the policy statement issued by the American College of Medical Genetics and published in 2005.

Micronutrients in pregnancy: current knowledge and unresolved questions

Micronutrient status is increasingly recognized to play an important role in the health and well-being of pregnant women and in the development and long-term health of the offspring. On 26th - 28th February 2009, The Child Health Foundation invited leading experts in this area to a scientific workshop at Obergurgl, Austria to review and critically discuss current knowledge, to identify issues that may need to be addressed in future recommendations, and to highlight priorities and opportunities for future research. This report summarizes updated key conclusions of the workshop with regards to micronutrients' intake and physiological role related to mother, placenta and fetus, as well as relevance for adverse pregnancy and long-term outcomes.

Biomarkers of cobalamin (vitamin B12) deficiency and its application

Cobalamin (vitamin B12) deficiency in the elderly is an under recognized problem in daily clinical practice. It seems to be important because the deficiency of this vitamin can lead to irreversible neurological damage, anemia, osteoporosis, and cerebrovascular and cardiovascular diseases. Some clinical abnormalities that we thought were related to the normal aging changes may actually be caused by cobalamin deficiency, such as lack of ankle jerk reflex. The prevalence of cobalamin deficiency increases with age (ranges from 0.6% to 46% depending on the population studies and criteria for diagnosis). Other than clinical manifestations, there are some biomarkers for detection of cobalamin deficiency: the red blood cell mean corpuscular volume (MCV); serum cobalamin level; plasma holotranscobalamin; serum methylmalonic acid (MMA) levels and serum homocysteine levels. The interpretation and the application of these biomarkers are here presented.

Perinatal folate supply: relevance in health outcome parameters

The importance of physiological supply of folate is well recognized in human health; the crucial roles of folate in one-carbon metabolism for physiological DNA synthesis and cell division, as well as in the conversion of homocysteine (Hcy) to methionine, and subsequently, to S-adenosylmethionine, have been convincingly demonstrated. Improved folate status may reduce the risk of macrocytic anaemia, cardiovascular diseases, neuropsychiatric disorders and adverse pregnancy outcomes. Inadequate folate status results in a decrease in the methylation cycle and in increased blood levels of the neurotoxic Hcy. The aim of this review is to provide insight into the influence of folate status on pregnancy health outcomes, and to consider increasing evidence of a link between the extent of genome/epigenome damage and elevated risk for adverse obstetrical endpoints. Pregnant women are at risk for folate insufficiency because of the increased need for folate for rapid fetal growth, placental development and enlargement of the uterus. Inadequate folate status may cause fetal malformations, impaired fetal growth, pre-term delivery and maternal anaemia. Even some diseases of the placenta may arise from folate deficiencies. Fetal growth seems to be vulnerable to maternal folate status during the periconception period, because it has the potential to affect both the closure of the neural tube and several epigenetic mechanisms within the placenta and the fetus. Mainly on the basis of the well recognized link between maternal folate status and fetal neural tube defects, women are advised to receive folic acid supplement during the periconceptional period. Because an adequate folate supply seems to play an important role in the implantation and development of the placenta and in improving endothelial function, folic acid supplementation in the late first trimester or early second trimester might also be beneficial.

Circulating unmetabolized folic acid and 5-methyltetrahydrofolate in relation to anemia, macrocytosis, and cognitive test performance in American seniors

BACKGROUND

Folate deficiency has serious consequences for the fetus. Folic acid fortification of food addresses this problem. However, clinical consequences of vitamin B-12 deficiency may be worsened by high folic acid intakes, perhaps as a direct result of unmetabolized folic acid, which does not occur naturally in body tissues.

OBJECTIVE

We attempted to attribute associations that we previously found between higher folate status and anemia and cognitive test performance to circulating unmetabolized folic acid or 5-methyltetrahydrofolate (5MeTHF).

DESIGN

The subjects (n = 1858) were senior participants in the US National Health and Nutrition Examination Survey (1999-2002) who had normal renal function and reported no history of stroke, recent anemia therapy, or diseases of the liver, thyroid, or coronary arteries. Subjects had undergone a phlebotomy, a complete blood count, and cognitive and dietary assessments.

RESULTS

Circulating unmetabolized folic acid was detected in approximately 33% of the subjects and was related to an increased odds of anemia in alcohol users. In seniors with a serum vitamin B-12 concentration <148 pmol/L or a plasma methylmalonic acid concentration > or =210 nmol/L, the presence compared with the absence of detectable circulating unmetabolized folic acid was related to lower cognitive test scores and lower mean cell volume. In the same subgroup, higher serum 5MeTHF was related to an increased odds of anemia and a marginally significantly decreased odds of macrocytosis. In seniors with a normal vitamin B-12 status, a higher serum 5MeTHF concentration was related to higher cognitive test scores.

CONCLUSION

Results of this epidemiologic study were somewhat consistent with reports on the folic acid treatment of patients with pernicious anemia, but some findings were unexpected.

High frequency of vitamin B12 deficiency in a Brazilian population

OBJECTIVE

There are few studies regarding vitamin B12 deficiency in developing countries. In Brazil, a late diagnosis of vitamin B12 deficiency progressing to severe neurological damage is common. Thus, the aim of the present study was to verify the frequency of vitamin B12 deficiency in two Brazilian populations (elderly and adult participants) and to compare different methods of vitamin B12 deficiency detection.

DESIGN

Five hundred participants were recruited from health centres from south-east Brazil and were separated into two groups: 60 years old or more and 30-59 years old. Vitamin B12 and folate concentrations were measured using electrochemiluminescence immunoassay (ECI) and RIA. Methylmalonic acid (MMA) was measured by LC coupled to tandem MS. Full blood counts were acquired using standard methods.

RESULTS

All participants had normal blood count results and mean cell volume less than 99 fl; none of them presented folate deficiency according to the results, which were all greater than 3 ng/ml. Cobalamin levels less than 200 pmol/l were identified by one of the two or by both methods in 7.2 % of the participants aged 60 years or more and 6.4 % of the participants aged 30-59 years. MMA levels were higher in older subjects (P = 0.007) compared with younger subjects. A greater correlation of MMA v. RIA was observed than of MMA v. ECI (P = 0.0017 v. P = 0.014). MMA quantification estimated that cobalamin deficiency was present in more than 11 % of the subjects for both studied groups.

CONCLUSIONS

The study shows that vitamin B12 deficiency is frequent in Brazilian adults and suggests that RIA is more sensitive than ECl for measuring cobalamin levels.

Increases in plasma holotranscobalamin can be used to assess vitamin B-12 absorption in individuals with low plasma vitamin B-12

Low plasma concentrations of vitamin B-12 are common in Indians, possibly due to low dietary intakes of animal-source foods. Whether malabsorption of the vitamin contributes to this has not been investigated. A rise in the plasma holotranscobalamin (holo-TC) concentration after a standard dose of oral vitamin B-12 has been proposed as a measure of gastrointestinal absorption in people with normal plasma vitamin B-12 concentrations. We studied 313 individuals (children and parents, 109 families) in the Pune Maternal Nutrition Study. They received 3 doses of 10 microg (n = 191) or 2 microg (n = 122) of cyanocobalamin at 6-h intervals. A rise in plasma holo-TC of > or =15% and >15 pmol/L above baseline was considered normal vitamin B-12 absorption. The baseline plasma vitamin B-12 concentration was <150 pmol/L in 48% of participants; holo-TC was <35 pmol/L in 98% and total homocysteine was high in 50% of participants (>10 micromol/L in children and >15 micromol/L in adults). In the 10 microg group, the plasma holo-TC concentration increased by 4.8-fold from (mean +/- SD) 9.3 +/- 7.0 pmol/L to 53.8 +/- 25.9 pmol/L and in the 2 microg group by 2.2-fold from 11.1 +/- 8.5 pmol/L to 35.7 +/- 19.3 pmol/L. Only 10% of the participants, mostly fathers, had an increase less than the suggested cut-points. Our results suggest that an increase in plasma holo-TC may be used to assess vitamin B-12 absorption in individuals with low vitamin B-12 status. Because malabsorption is unlikely to be a major reason for the low plasma vitamin B-12 concentrations in this population, increasing dietary vitamin B-12 should improve their status.

Bacterial vitamin B2, B11 and B12 overproduction: An overview

Consumers are becoming increasingly health conscious and therefore more discerning in their food choices. The production of fermented food products with elevated levels of B-vitamins increase both their commercial and nutritional value, and eliminate the need for subsequent fortification with these essential vitamins. Such novel products could reduce the incidence of inadequate vitamin intake which is common in many parts of the world, not only in developing countries, but also in many industrialised countries. Moreover, the concept of in situ fortification by bacterial fermentation opens the way for development of food products targeted at specific groups in society such as the elderly and adolescents. This review looks at how vitamin overproduction strategies have been developed, some of which have successfully been tested in animal models. Such innovative strategies could be relatively easily adapted by the food industry to develop novel vitamin-enhanced functional foods with enhanced consumer appeal.