Nutritional Folate Deficiency Research Articles

The impact of nutritional vitamin B12, folate and hemoglobin deficiency on school performance of elementary school children

Deficiencies of nutrients such as vitamin B12, folic acid and iron are frequently associated with impairment of memory, concentration and learning ability. Deficiencies of these micronutrients are very rare in Western countries, whereas they are common in developing countries. This study was carried out to determine the impact of vitamin B12 deficiency, folic acid deficiency and/or anemia on the academic achievement of elementary school children from a low socio-economic population, i.e., impoverished Bedouin population living in southern Israel. Sixty-seven elementary school children, nine to eleven years of age, were randomly tested. Serum levels of vitamin B12, folic acid, and hemoglobin were measured using automated chemiluminescence systems. An individual questionnaire was filled out for each student, which included information on number of meat meals consumed per week, the number of people in the family and information about the father's employment status. Significant positive correlations were observed between number of meat meals consumed per week and low vitamin B12 levels and attainment of low marks in school, respectively. There was a negative correlation between the total number of family members and the attainment of low marks in school. No correlation between anemia or low folic acid levels and school performance was observed. Despite the small sample number, results indicated a high prevalence of vitamin B12 deficiency among these elementary school children, which could be linked to inadequate meat meal intake. This ultimately affected school performance of these children.

Nutritional B vitamin deficiency alters the expression of key proteins associated with vascular smooth muscle cell proliferation and migration in the aorta of atherosclerotic apolipoprotein E null mice.

Low B vitamin status is linked with human vascular disease. We employed a proteomic and biochemical approach to determine whether nutritional folate deficiency and/or hyperhomocysteinemia altered metabolic processes linked with atherosclerosis in ApoE null mice. Animals were fed either a control fat (C; 4% w/w lard) or a high-fat [HF; 21% w/w lard and cholesterol (0/15% w/w)] diet with different B vitamin compositions for 16weeks. Aorta tissue was prepared and global protein expression, B vitamin, homocysteine and lipoprotein status measured. Changes in the expression of aorta proteins were detected in response to multiple B vitamin deficiency combined with a high-fat diet (P<0.05) and were strongly linked with lipoprotein concentrations measured directly in the aorta adventitia (P<0.001). Pathway analysis revealed treatment effects in the aorta-related primarily to cytoskeletal organisation, smooth muscle cell adhesion and invasiveness (e.g., fibrinogen, moesin, transgelin, vimentin). Combined B vitamin deficiency induced striking quantitative changes in the expression of aorta proteins in atherosclerotic ApoE null mice. Deregulated expression of these proteins is associated with human atherosclerosis. Cellular pathways altered by B vitamin status included cytoskeletal organisation, cell differentiation and migration, oxidative stress and chronic inflammation. These findings provide new insight into the molecular mechanisms through which B vitamin deficiency may accelerate atherosclerosis.

Influence of Physiologic Folate Deficiency on Human Papillomavirus Type 16 (HPV16)-harboring Human Keratinocytes in Vitro and in Vivo

Although HPV16 transforms infected epithelial tissues to cancer in the presence of several co-factors, there is insufficient molecular evidence that poor nutrition has any such role. Because physiological folate deficiency led to the intracellular homocysteinylation of heterogeneous nuclear ribonucleoprotein E1 (hnRNP-E1) and activated a nutrition-sensitive (homocysteine-responsive) posttranscriptional RNA operon that included interaction with HPV16 L2 mRNA, we investigated the functional consequences of folate deficiency on HPV16 in immortalized HPV16-harboring human (BC-1-Ep/SL) keratinocytes and HPV16-organotypic rafts. Although homocysteinylated hnRNP-E1 interacted with HPV16 L2 mRNA cis-element, it also specifically bound another HPV16 57-nucleotide poly(U)-rich cis-element in the early polyadenylation element (upstream of L2L1 genes) with greater affinity. Together, these interactions led to a profound reduction of both L1 and L2 mRNA and proteins without effects on HPV16 E6 and E7 in vitro, and in cultured keratinocyte monolayers and HPV16-low folate-organotypic rafts developed in physiological low folate medium. In addition, HPV16-low folate-organotypic rafts contained fewer HPV16 viral particles, a similar HPV16 DNA viral load, and a much greater extent of integration of HPV16 DNA into genomic DNA when compared with HPV16-high folate-organotypic rafts. Subcutaneous implantation of 18-day old HPV16-low folate-organotypic rafts into folate-replete immunodeficient mice transformed this benign keratinocyte-derived raft tissue into an aggressive HPV16-induced cancer within 12 weeks. Collectively, these studies establish a likely molecular linkage between poor folate nutrition and HPV16 and predict that nutritional folate and/or vitamin-B(12) deficiency, which are both common worldwide, will alter the natural history of HPV16 infections and also warrant serious consideration as reversible co-factors in oncogenic transformation of HPV16-infected tissues to cancer.

Pneumocystis jiroveci Pneumonia in an Infant With Severe Folate Deficiency

Pneumocystis jiroveci pneumonia is rare in immunocompetent children. Severe folate deficiency affects T cell function, potentially increasing susceptibility to opportunistic pathogens. We report the case of an 11-month-old child who developed P. jiroveci pneumonia in the setting of severe nutritional folate deficiency and review the literature regarding the influence of folate on immunity.

Short-term nutritional folate deficiency in rats has a greater effect on choline and acetylcholine metabolism in the peripheral nervous system than in the brain, and this effect escalates with age

The hypothesis of this study is that a folate-deficient diet (FD) has a greater effect on cholinergic system in the peripheral nervous system than in the brain, and that this effect escalates with age. It was tested by comparing choline and acetylcholine levels in male Sprague Dawley rats fed either control or folate-deficient diets for 10 weeks, starting at age 4 weeks (the young group) or 9 months (the adult group). Folate-deficient diet consumption resulted in depletion of plasma folate in both age groups. In young folate-deficient rats, liver and lung choline levels were significantly lower than those in the respective controls. No other significant effects of FD on choline and acetylcholine metabolism were found in young rats. In adult rats, FD consumption markedly decreased choline levels in the liver, kidneys, and heart; furthermore, choline levels in the cortex and striatum were moderately elevated, although hippocampal choline levels were not affected. Acetylcholine levels were higher in the heart, cortex, and striatum but lower in the hippocampus in adult folate-deficient rats, as compared to controls. Higher acetylcholine levels in the striatum in adult folate-deficient rats were also associated with higher dopamine release in the striatal slices. Thus, both age groups showed higher cholinergic metabolic sensitivity to FD in the peripheral nervous system than in the brain. However, compensatory abilities appeared to be better in the young group, implicating the adult group as a preferred model for further investigation of folate-choline-acetylcholine interactions and their role in brain plasticity and cognitive functions.

Nutrition, Epigenetics and Complex Birth Defects

Birth defects are a global problem that affects ~6% of births worldwide. In the U.S., birth defects are the leading cause of pediatric hospitalizations, medical expenditures, and death in the first year of life. Globally, at least 3.3 million children &lt;5 years die each year because of a birth defect. Indeed, birth defects are one of, if not the leading healthcare concern for the youngest members of society. Neural tube defects (NTDs) are the 2nd most common of all human birth defects, annually affecting approximately 324,000 births worldwide and 3,000 pregnancies in the U.S.We have explored the potential role of environmental factors that alter maternal epigenetic homeostasis and contributes to birth defects. We believe that environmental exposures or nutritional status can impact production of reactive oxidative molecules, the availability of methyl groups, methyltransferase activity, inflammation and endocrine disruption which all have epigenetic implications during the process of neural tube closure. Such exposures may modify multiple biological processes that affect epigenetic mechanisms, including DNA methylation, histone codes, and miRNA expression. These changes may, in turn, modify chromatin organization and condensation, gene expression, and adversely affect pathogenetic processes in the developing embryo. Such factors may interact and act synergistically, such as a nutritional folate deficiency may create altered immune responses that compromise neural tube closure. An in depth exploration of the epigenetic relationship between environmental toxicants, nutritional status and the developmental impact on the embryo will be the focus of this presentation.Supported by NIH grants DE016315 and NS050249

Folate Receptor Alpha Defect Causes Cerebral Folate Transport Deficiency: A Treatable Neurodegenerative Disorder Associated with Disturbed Myelin Metabolism

Sufficient folate supplementation is essential for a multitude of biological processes and diverse organ systems. At least five distinct inherited disorders of folate transport and metabolism are presently known, all of which cause systemic folate deficiency. We identified an inherited brain-specific folate transport defect that is caused by mutations in the folate receptor 1 (FOLR1) gene coding for folate receptor alpha (FRalpha). Three patients carrying FOLR1 mutations developed progressive movement disturbance, psychomotor decline, and epilepsy and showed severely reduced folate concentrations in the cerebrospinal fluid (CSF). Brain magnetic resonance imaging (MRI) demonstrated profound hypomyelination, and MR-based in vivo metabolite analysis indicated a combined depletion of white-matter choline and inositol. Retroviral transfection of patient cells with either FRalpha or FRbeta could rescue folate binding. Furthermore, CSF folate concentrations, as well as glial choline and inositol depletion, were restored by folinic acid therapy and preceded clinical improvements. Our studies not only characterize a previously unknown and treatable disorder of early childhood, but also provide new insights into the folate metabolic pathways involved in postnatal myelination and brain development.

Folate Deficiency Induces Genomic Uracil Misincorporation and Hypomethylation But Does Not Increase DNA Point Mutations

Epidemiologic studies have linked nutritional folate deficiency to an increased risk of cancer, but recent trials suggest that folate supplementation does not protect against tumor formation. Our aim was to analyze the genetic and epigenetic consequences of folate deficiency and to investigate whether impairment of the uracil base excision repair pathway can enhance its effects. Wild-type mice and those deficient in uracil DNA glycosylase (Ung(-/-)) were placed on a folate-deficient diet for 8 months. We measured tumor incidence in major organs, DNA mutation rates, DNA mutation spectra, local DNA methylation, and global DNA methylation in colon epithelial cells. The experimental diet increased plasma homocysteine (60%, P< .001) and DNA uracil content (24%, P< .05) but not tumor formation. Global DNA methylation was slightly decreased in splenocytes (9.1%) and small intestinal epithelial cells (4.2%), and significantly reduced in colon epithelial cells (7.2%, P< .04). No gene-specific changes in methylation were detected at the mouse B1 element, the H19 DMR, or the Oct4 gene. By lambda CII assay and sequencing analysis of 730 mutants, we found that Ung(-/-) mice had a higher frequency of point mutations and increased C:G to T:A transitions at non-CpG sites. However, folate deficiency had no additional effect on the DNA mutation frequency or spectrum in Ung(-/-) or wild-type mice. Contradicting current concepts, these findings indicate that the effects of a low-folate diet on DNA methylation and point mutations are insufficient to promote tumor development, even in the presence of Ung deficiency.

Molecular and cellular biology of the human reduced folate carrier

The natural folates are water-soluble members of the B class of vitamins that are essential for cell proliferation and tissue regeneration. Since mammalian cells cannot synthesize folates de novo, tightly regulated and sophisticated cellular uptake processes have evolved to sustain sufficient levels of intracellular tetrahydrofolate cofactors to support the biosynthesis of purines, pyrimidines, serine, and methione. Membrane transport is also a critical determinant of the antitumor activity of antifolate therapeutics (methotrexate, Tomudex) used in cancer chemotherapy, and impaired uptake of antifolates is a frequent mode of drug resistance. The reduced folate carrier is the major transport system for folates and classical antifolates in mammalian cells and tissues. This review summarizes the remarkable advances in the cellular and molecular biology of the human reduced folate carrier over the past decade, relating to its molecular structure and transport function, mechanisms of transcriptional and posttranscriptional regulation, and its critical role in antifolate response and resistance. Many key in vitro findings have now begun to be extended to studies of reduced folate carrier levels and function in patient specimens, paving the way for translating basic laboratory studies in cultured cells to improvements in human health and treatment of disease. The results of research into the human reduced folate carrier should clarify the roles of changes in expression and function of this system that accompany nutritional folate deficiency and human disease, and may lead to improved therapeutic strategies for enhancing drug response and circumventing resistance in cancer patients undergoing chemotherapy with antifolates.

Folate deficiency reduces the GPI-anchored folate-binding protein in rat renal tubules.

A folate-binding protein (FBP) anchored to cell membranes by a glycosyl phosphatidylinositol (GPI) adduct is constitutively expressed in some transformed and cultured cell lines. Its expression is upregulated when these cells are grown in medium containing low folate, but whether this occurs in vivo with nutritional folate deficiency is unknown. To address this question, the GPI-FBP in the liver, kidney, and brain of rats on control and folate-deficient (FD) diets was measured. The GPI-FBP in the kidney of FD rats decreased significantly in contrast to the upregulation of this protein in cultured cells. Northern blot analysis and nuclear run-on assays indicated that transcription of the GPI-FBP gene in the kidney was not reduced by folate deficiency. This decrease of the GPI-FBP appears to result from its proteolysis, similar to the enzymatic degradation of the apoprotein that occurs in vitro. Because the GPI-FBP is on the brush borders of the proximal renal tubules and provides for the reabsorption of folate, this function diminishes when the protein decreases in folate deficiency.

Nutritional folate deficiency augments the in vivo mutagenic and lymphocytotoxic activities of alkylating agents

To investigate the interaction of folate deficiency and alkylating agents in vivo, weanling Fischer 344 rats were maintained for 5 weeks on a folate replete, moderately folate deficient, or a severely folate deficient diet. Mutant frequencies at the HPRT locus in splenic lymphocytes were 1.2+/-0.6, 1.9+/-1.1, and 6.4+/-4.0 x 10(-6), respectively (P < 0.01). N-nitroso-N-ethylurea (ENU), 100 mg/kg body weight, was much more mutagenic with progressive folate deficiency (5.0+/-2.4 vs. 16.2+/-7.3 vs. 39.2+/-21.0 x 10(-6)), suggesting a synergistic interaction (P << 0.01). Neither moderate nor severe folate deficiency significantly enhanced the mutagenic effects of cyclophosphamide, 50 mg/kg body weight (18.0+/-7.9 vs. 6.0+/-2.8 vs. 28.5+/-28.2 x 10(-6)). The number of cloning cells/ spleen were reduced 68% in moderately folate deficient rats and by 87% in severely deficient animals (P < 0.05). The combination of folate deficiency and cyclophosphamide reduced the total number of cloning cells further, but ENU alone, or in combination with folate deficiency, did not. These findings indicate that folate deficiency increases the risk of somatic mutations and is lymphocytotoxic in rats. Folate deficiency enhances the mutagenic but not the lymphotoxic effects of ENU, while it increases the lymphotoxic but not the mutagenic activity of cyclophosphamide. Correction of folate deficiency may decrease the immunologic and genetic damage caused by some alkylating agents.

Effects of folate deficiency and supplementation on methylnitrosourea-induced rat mammary tumors.

There are metabolic and epidemiologic data consistent with the hypothesis that folate deficiency increases the likelihood of cancer. Conversely, it is also known that folate is necessary for cancer growth, but few experiments in laboratory animals have evaluated the effects of folate deficiency on the development of chemically induced cancers. Our purpose was to determine the effects of nutritional folate deficiency in female Fischer 344 rats on initiation and early promotion of methylnitrosourea (MNU)-induced mammary cancer. Rats (age, 27 days) were fed a folic acid-deficient diet (AIN-76A) supplemented with glycine and succinylsulfathiazole [FA(0)]; the FA(0) diet supplemented with 2 or 40 mg of folic acid per kilogram [FA(2) or FA(40), respectively]; or the FA(0) diet supplemented with 20 mg of folinic acid per kilogram [FL(20)]. At 57 days of age, each diet-treated group (30 rats in each group) received MNU (50 mg/kg) by intravenous injection. Immediately after MNU treatment, all animals were fed the AIN-76A complete diet containing 2 mg of folic acid per kilogram. Control groups were fed the AIN-76A complete diet throughout the entire experiment. After 4 weeks, folate deficiency, but not anemia or growth suppression, was documented by lower folate levels in plasma and red blood cells in the group receiving the FA(0) diet. Cancer multiplicity (i.e., number of mammary cancers per number of tumor-bearing animals) at 180 days after MNU injection was 1.32, 1.90, 2.14, and 2.73 mammary cancers per tumor-bearing animal in the FA(0), FA(2), FA(40), and FL(20) groups, respectively; the value in the FA(0) group was statistically significant compared with the values in the other groups. The time required for 50% of the rats to develop palpable mammary cancer was 170, 142, 100, and 85 days, respectively. The value of 170 days for the FA(0) group was statistically significant compared with the values of 100 and 85 days. Mammary cancer incidence was 63%, 70%, 72%, and 73%, respectively; these percentages were not significantly different. Folate deficiency suppresses and folate supplementation enhances initiation or early promotion of MNU-induced mammary cancer in rats, even when the folate-deficient rats do not have anemia or growth suppression. Since the rat is relatively resistant to folate deficiency anemia, other animal models should be used to test the effect of folate nutriture on carcinogenesis.

Effects of nutritional folate deficiency on the adhesive properties of murine melanoma cells

Folate deficient murine B16 melanoma cells adhered more rapidly and in higher percentages to plastic plates or dishes coated with laminin or fibronectin than folate replete cells. These changes in the adhesive properties of murine melanoma cells induced by nutritional folate deficiency were not mediated by changes in cell size, proliferative capacity or cell cycle distribution. While melanoma cells served as a suitable surface for prothrombinase complex formation, folate deficiency did not alter this membrane function, suggesting that the membrane changes associated with folate deficiency are relatively specific.

Nutritional folate deficiency in Chinese hamster ovary cells. I. Characterization of the pleiotropic response and its modulation by nucleic acid precursors.

Nutritional folate deficiency in Chinese hamster ovary (CHO)-K1 cells inhibited population growth rate and caused growth arrest within 3 days of culture in Fol- medium [without folate, hypoxanthine (Hx), and thymidine (TdR)]. Coincident with impaired population growth was a transient delay in cell cycle progression through S phase and an increase in cell size. The growth-arrested population of predominantly G1 phase cells exhibited an increased adhesion to the culture substratum. There was a time-dependent loss of cell reproductive capacity. All these various perturbations of cellular phenotype induced by folate deficiency were prevented by the addition of folate or a combination of TdR and Hx to the Fol- medium. However, the singular presence of each nucleotide precursor differentially affected the pleiotropic response. The addition of Hx to Fol- medium exacerbated the aforementioned abnormalities, producing a threefold increase in mean cell volume, a 72 hr accumulation of cells in the S phase of the cell cycle, and a rapid demise in cell clonogenicity. Unexpectedly, we found reduced cell adhesion in these cultures. In contrast, folate-deficient cells supplemented with TdR exhibited a general amelioration of cell perturbations with respect to cell size, cell cycle distribution, and reproductive viability. Notably, such populations were not released from growth inhibition or subsequent growth arrest, and the cells became elongated and highly adherent with time. When cell populations from each of the three conditions of folate-deficient culture were released from growth arrest by addition of complete medium, the respective profiles of synchronous cell cycle progression were distinctive.

Effect of folate deficiency on vitamin B12 absorption.

In three different groups of patients presenting severe folate deficiency (purely nutritional folate deficiency, chronic alcoholism or various intestinal diseases), vitamin B12 absorption has been tested by Schilling test in order to investigate the possible effect of folate deficiency on B12 absorption. Following this study, it appears that folate deficiency in itself, even severe, cannot induce vitamin B12 malabsorption, since in the first group, consisting of malnourished old people, the Schilling test was always normal even in those who presented a lowered B12 serum level; in the group of patients with intestinal disease, the Schilling test was abnormal as expected in some patients; 3 alcoholics out of 12 presented a malabsorption of B12 on the Schilling test; the follow-up of 2 of them exhibited complete correction after normal diet and alcohol suppression. Consequently, folate deficiency does not seem responsible for a secondary B12 malabsorption unless another etiological factor is present, such as alcohol or ileopathy.

Reversible malabsorption of folic acid in the elderly with nutritional folate deficiency.

In normal subjects, the folic acid absorption (TRIFA test) was independent of age and sex. Among 53 geriatric patients with nutritional folate deficiency, impaired absorption of folic acid was present in 19 (36%). After treatment with folic acid for 4 weeks, the absorption returned to normal. It is concluded that folate deficiency per se can produce a malabsorption syndrome resulting in further depletion of folate. Protein deficiency and weight loss alone do not impair the absorption of folic acid.

Malabsorption of dietary folate (Pteroylpolyglutamates) in adult coeliac disease and dermatitis herpetiformis.

Tests of absorption of folic acid (pteroylglutamic acid) and of dietary folates (pteroylpolyglutamates) were performed in 10 patients with untreated adult coeliac disease, five with dermatitis herpetiformis, and three with nutritional folate deficiency. Absorption of pteroylglutamic acid was impaired in eight patients with coeliac disease and in two with dermatitis herpetiformis. Absorption of pteroylpolyglutamates was impaired in all 10 coeliac patients and in four of the five patients with dermatitis herpetiformis. Absorption of both forms of folate was normal in all three patients with nutritional folate deficiency.

Nutritional folate deficiency in the United Kingdom.

Nutritional folate deficiency in the United Kingdom.

Nutritional Folate Deficiency

Nutritional Folate Deficiency

Nutritional folate deficiency.

Nutritional folate deficiency.