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Query: UMLS:C0240066 (iron deficiency)
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Twenty-two percent of women in the United States are iron deficient. Iron deficiency adversely affects immune function as well as physical and cognitive performance. Although the risk of developing iron deficiency is high for female soldiers, this risk can be minimized with proper nutritional guidance. Recommended dietary modifications include (1) heme iron consumption, (2) ingestion of vitamin C and protein with meals, and (3) discontinued tea and coffee consumption with meals.
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PMID:Iron supplementation and the female soldier. 1667 42

The objective of this update is to give an overview of the effects of dietary nutrients on the structure and certain functions of the brain. As any other organ, the brain is elaborated from substances present in the diet (sometimes exclusively, for vitamins, minerals, essential amino-acids and essential fatty acids, including omega- 3 polyunsaturated fatty acids). However, for long it was not fully accepted that food can have an influence on brain structure, and thus on its function, including cognitive and intellectuals. In fact, most micronutrients (vitamins and trace-elements) have been directly evaluated in the setting of cerebral functioning. For instance, to produce energy, the use of glucose by nervous tissue implies the presence of vitamin B1; this vitamin modulates cognitive performance, especially in the elderly. Vitamin B9 preserves brain during its development and memory during ageing. Vitamin B6 is likely to benefit in treating premenstrual depression. Vitamins B6 and B12, among others, are directly involved in the synthesis of some neurotransmitters. Vitamin B12 delays the onset of signs of dementia (and blood abnormalities), provided it is administered in a precise clinical timing window, before the onset of the first symptoms. Supplementation with cobalamin improves cerebral and cognitive functions in the elderly; it frequently improves the functioning of factors related to the frontal lobe, as well as the language function of those with cognitive disorders. Adolescents who have a borderline level of vitamin B12 develop signs of cognitive changes. In the brain, the nerve endings contain the highest concentrations of vitamin C in the human body (after the suprarenal glands). Vitamin D (or certain of its analogues) could be of interest in the prevention of various aspects of neurodegenerative or neuroimmune diseases. Among the various vitamin E components (tocopherols and tocotrienols), only alpha-tocopherol is actively uptaken by the brain and is directly involved in nervous membranes protection. Even vitamin K has been involved in nervous tissue biochemistry. Iron is necessary to ensure oxygenation and to produce energy in the cerebral parenchyma (via cytochrome oxidase), and for the synthesis of neurotransmitters and myelin; iron deficiency is found in children with attention-deficit/hyperactivity disorder. Iron concentrations in the umbilical artery are critical during the development of the foetus, and in relation with the IQ in the child; infantile anaemia with its associated iron deficiency is linked to perturbation of the development of cognitive functions. Iron deficiency anaemia is common, particularly in women, and is associated, for instance, with apathy, depression and rapid fatigue when exercising. Lithium importance, at least in psychiatry, is known for a long time. Magnesium plays important roles in all the major metabolisms: in oxidation-reduction and in ionic regulation, among others. Zinc participates among others in the perception of taste. An unbalanced copper metabolism homeostasis (due to dietary deficiency) could be linked to Alzheimer disease. The iodine provided by the thyroid hormone ensures the energy metabolism of the cerebral cells; the dietary reduction of iodine during pregnancy induces severe cerebral dysfunction, actually leading to cretinism. Among many mechanisms, manganese, copper, and zinc participate in enzymatic mechanisms that protect against free radicals, toxic derivatives of oxygen. More specifically, the full genetic potential of the child for physical growth ad mental development may be compromised due to deficiency (even subclinical) of micronutrients. Children and adolescents with poor nutritional status are exposed to alterations of mental and behavioural functions that can be corrected by dietary measures, but only to certain extend. Indeed, nutrient composition and meal pattern can exert either immediate or long-term effects, beneficial or adverse. Brain diseases during aging can also be due to failure for protective mechanism, due to dietary deficiencies, for instance in anti-oxidants and nutrients (trace elements, vitamins, non essential micronutrients such as polyphenols) related with protection against free radicals. Macronutrients are presented in the accompanying paper.
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PMID:Effects of nutrients (in food) on the structure and function of the nervous system: update on dietary requirements for brain. Part 1: micronutrients. 1706 9

Recombinant human erythropoietin (rHuEPO) has transformed the management chronic renal failure (CKD) and considerably improved the outcome of patients on regular chronic dialysis. However, a significant number of patients fail to respond to high of Erythropoiesis-stimulating agents (ESAs) and several causes of inadequate response to epoetin therapy have been identified. Some factors, such as gender, age, length of time on dialysis, type of dialysis and co-morbidities such as hemoglobinopathy, are not susceptible to clinical intervention. However, many other factors can be adjusted. Iron deficiency, whether functional or absolute, is the most common factor that limits the response to rHuEPO. Monitoring of iron parameters and a large use of iron supplementation result in an efficient epoetin response. Infection and inflammation have been shown to reduce responsiveness to ESAs by disrupting iron metabolism and increasing the release of pro-inflammatory cytokines that inhibit erythropoiesis. Increase dialysis dose is associated with improvements in anemia correction and reduced requirements for ESAs. Severe hyperparathyroidism and aluminum overload lead to a reduced number of responsive erythroid progenitor cells. Finally, a number of nutritional factors, such as deficiencies of carnitine, vitamin B12, folic acid, and vitamin C, are susceptible to alter erythropoiesis. Optimizing patient response to ESAs therefore requires consideration of many of well-established factors and is important for both patient outcomes and cost of treatment.
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PMID:[Factors affecting the response to erythropoiesis-stimulating agents]. 1737 70

Approximately 5-10% of patients with chronic kidney disease demonstrate hyporesponsiveness to erythropoiesis-stimulating agents (ESA), defined as a continued need for greater than 300 IU/kg per week erythropoietin or 1.5 mug/kg per week darbepoetin administered by the subcutaneous route. Such hyporesponsiveness contributes significantly to morbidity, mortality and health-care economic burden in chronic kidney disease and represents an important diagnostic and management challenge. The commonest causes of ESA resistance are non-compliance, absolute or functional iron deficiency and inflammation. It is widely accepted that maintaining adequate iron stores, ideally by administering iron parenterally, is the most important strategy for reducing the requirements for, and enhancing the efficacy of ESA. There have been recent epidemiologic studies linking parenteral iron therapy to an increased risk of infection and atherosclerosis, although other investigations have refuted this. Inflammatory ESA hyporesponsiveness has been reported to be improved by a number of interventions, including the use of biocompatible membranes, ultrapure dialysate, transplant nephrectomy, ascorbic acid therapy, vitamin E supplementation, statins and oxpentifylline administration. Other variably well-established causes of ESA hyporesponsiveness include inadequate dialysis, hyperparathyroidism, nutrient deficiencies (vitamin B12, folate, vitamin C, carnitine), angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, aluminium overload, antibody-mediated pure red cell aplasia, primary bone marrow disorders, myelosuppressive agents, haemoglobinopathies, haemolysis and hypersplenism. This paper reviews the causes of ESA hyporesponsiveness and the clinical evidence for proposed therapeutic interventions. A practical algorithm for approaching the investigation and management of patients with ESA hyporesponsiveness is also provided.
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PMID:Erythropoiesis-stimulating agent hyporesponsiveness. 1763 45

The objective of this study was to estimate the amount of bioavailable iron (FeBIO) in the diet of Mexican children aged 12-59 mo through the application of algorithms that use dietary variables and analyze the association between estimated FeBIO and hemoglobin (Hb) concentration. Data were analyzed for 919 children aged 12-59 mo old who participated in a national probabilistic survey on nutrition, in which a 24-h dietary recall was applied and Hb concentration was determined through the use of portable photometers. Dietary intakes were determined for total iron, heme and nonheme iron, vitamin C, phytates, and meat (red meat, poultry, and fish). Using these dietary variables and distinct scenarios on body iron reserves, we used algorithms to estimate the amount of FeBIO in the diet. Linear regression models were adjusted to evaluate the association between FeBIO and Hb. The mean iron intake was 6.2 +/- 4.4 mg/d and the mean estimated FeBIO ranged between 0.14 and 0.37 mg/d depending on different assumptions about iron reserves, representing 2.7-6.1% of total iron intake. The Hb concentration, adjusted for altitude and presence of diarrhea, was positively associated with FeBIO in children 12-23 mo old (P < 0.05) but not in children 24-59 mo old. The estimated FeBIO is low in relation to physiological requirements and is compatible with existing high iron deficiency prevalence rates in Mexico. Although Hb is not a specific indicator of iron status, it was significantly associated with FeBIO.
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PMID:Bioavailable dietary iron is associated with hemoglobin concentration in Mexican preschool children. 1788 15

Provision of sufficient available iron is a prerequisite to ensure the bodys optimal response to recombinant human erythropoietin (epoetin). Functional iron deficiency (a state when iron supply is reduced to meet the demands for increased erythropoiesis) is a common cause of poor response to epoetin in dialysis patients who have normal iron status, even when they are iron-overloaded. Iron supplementation is not justified for this hyporesponsiveness in patients with iron overload due to the potential hazards of iron overload aggravated by intravenous iron therapy. Furthermore, in vivo studies have indicated that the promising effect of intravenous iron medication to overcome iron-deficient erythropoiesis is not observed in iron-overloaded hemodialysis (HD) patients. Vitamin C, a water-soluble antioxidant as well as a reducing agent, has a number of associations with iron metabolism. Recent research highlights that vitamin C can potentiate the mobilization of iron from inert tissue stores and facilitates the incorporation of iron into protoporphyrin in HD patients being treated with epoetin. Interest has turned towards the use of vitamin C as an adjuvant therapy in this field. This review focuses on the improvement of epoetin response by administration of vitamin C and discusses its clinical implications and potential issues for internal medicine doctors.
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PMID:Novel aspects of vitamin C in epoetin response. 1790 48

Searching for economical, nonconventional sources of iron is important in underdeveloped countries to combat iron deficiency and anemia. Our objective was to study iron, vitamin C, and phytic acid composition and also iron bioavailability from 4 species of marine algae included in a rice-based meal. Marine algae (Ulva sp, Sargassum sp, Porphyra sp, and Gracilariopsis sp) were analyzed for monthly variations in iron and for ascorbic acid and phytic acid concentrations. A total of 96 subjects received rice-based meals containing the 4 species of marine algae in different proportions, raw or cooked. All meals contained radioactive iron. Absorption was evaluated by calculating the radioactive iron incorporation in subjects' blood. Iron concentrations in algae were high and varied widely, depending on the species and time of year. The highest iron concentrations were found in Sargassum (157 mg/100 g) and Gracilariopsis (196 mg/100 g). Phytates were not detected in the algae and ascorbic acid concentration fluctuated between 38 microg/g dry weight (Ulva) and 362 microg/g dry weight (Sargassum). Algae significantly increased iron absorption in rice-based meals. Cooking did not affect iron absorption compared with raw algae. Results indicate that Ulva sp, Sargassum sp, Porphyra sp, and Gracilariopsis sp are good sources of ascorbic acid and bioavailable iron. The percentage of iron absorption was similar among all algae tested, although Sargassum sp resulted in the highest iron intake. Based on these results, and on the high reproduction rates of algae during certain seasons, promoting algae consumption in some countries could help to improve iron nutrition.
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PMID:High iron content and bioavailability in humans from four species of marine algae. 1802 85

Morbid obesity is a health problem that has been shown to be refractory to diet, exercise, and medical treatment. Surgeries designed to promote weight loss, termed bariatric surgery and typically involving a gastric bypass procedure, have recently been implemented to treat obesity with high success rates. However, long-term sequelae can result in micronutrient deficiencies. This review will focus on iron deficiency and its association with obesity and bariatric surgery. Iron deficiency develops after gastric bypass for several reasons including intolerance for red meat, diminished gastric acid secretion, and exclusion of the duodenum from the alimentary tract. Menstruating women, pregnant women, and adolescents may be particularly predisposed toward developing iron deficiency and microcytic anemias after bypass surgery. Preoperative assessment of patients should include a complete hematological work-up, including measurement of iron stores. Postoperatively, oral iron prophylaxis and vitamin C in addition to a multivitamin should be prescribed for bypass patients, especially for vulnerable populations. Once iron deficiency has developed, it may prove refractory to oral treatment, and require parenteral iron, blood transfusions, or surgical interventions. Bariatric surgery patients require lifelong follow-up of hematological and iron parameters since iron deficiency and anemia may develop years after surgery.
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PMID:Obesity, bariatric surgery, and iron deficiency: true, true, true and related. 1806 40

Phytosiderophores (PS) are strong iron chelators, produced by graminaceous plants under iron deficiency. The ability of released PS to chelate iron(III), and subsequent uptake of this chelate into roots by YS1-type transport proteins, are well-known. The mechanism of iron release from the stable chelate inside the plant cell, however, is unclear. One possibility involves the reduction of ferric PS in the presence of an iron(II) chelator via ternary complex formation. Here, the conversion of ferric PS species by ascorbate in the presence of the intracellular ligand nicotianamine (NA) has been investigated at cytosolic pH (pH 7.3), leading to the formation of a ferrous NA chelate. This reaction takes place when supplying Fe(III) as a chelate with 2'-deoxymugineic acid (DMA), mugineic acid (MA), and 3-epi-hydroxymugineic acid (epi-HMA), with the reaction rate decreasing in this order. The progress of the conversion of ferric DMA to ferrous NA was monitored in real-time by high resolution mass spectrometry (FTICR-MS), and the results are complemented by electrochemical measurements (cyclic voltammetry), which allows detecting reactive intermediates and their change with time at high sensitivity. Hence, the combined results of electrochemistry and mass spectrometry indicate an ascorbate-mediated mechanism for the iron release from ferric PS, which highlights the role of ascorbate as a simple, but effective plant reductant.
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PMID:Investigation of ascorbate-mediated iron release from ferric phytosiderophores in the presence of nicotianamine. 1832 53

Iron deficiency (ID) is the most prevalent micronutrient deficiency in the world, particularly in developing countries. Blood samples and a qualitative FFQ on Fe- and vitamin C-rich foods were obtained in 180 adolescent girls aged 12 to 17 years living in two boarding schools from south Benin. ID, defined as serum ferritin either 73 micromol/l or transferrin saturation<20%, was found in 32% of subjects. Anaemia (Hb<120 g/l) was found in 51% of adolescents, while 24% suffered from iron-deficiency anaemia (IDA) (ID and Hb<20 g/l). After adjusting for confounding factors (age, mother's and father's occupation, household size) in a logistic regression equation, subjects having a low meat consumption (beef, mutton, pork) (<4 times/week) were more than twice as likely to suffer from ID (OR=2.43; 95% CI 1.72, 3.35; P=0.04). Adolescents consuming less fruits (<4 times/week) also had a higher likelihood of suffering from ID (OR=1.53; 95% CI 1.31, 2.80; P=0.03). Finally, subjects whose meat consumption was low were twice as likely to suffer from IDA (OR=2.24; 95% CI 1.01, 4.96; P=0.04). The prevalence of ID represents an important health problem in these Beninese adolescent girls. A higher consumption of Fe-rich foods and of promoters of Fe absorption (meat factor and vitamin C) is recommended to prevent ID deficiency in these subjects.
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PMID:Iron status of adolescent girls from two boarding schools in southern Benin. 1832 33


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