Prevalence of iron deficiency in the United States

Plasma micronutrient concentrations in infants undergoing therapy for phenylketonuria

Twenty-seven infants with classical phenylketonuria were evaluated longitudinally for 6 mo while ingesting Phenex-1 Amino Acid Modified Medical Food With Iron as their primary protein source. Intake of selected nutrients and biochemical indices of trace and ultratrace mineral status and plasma retinol and alpha-tocopherol concentrations were evaluated. The means of iron status indices (complete blood count, plasma ferritin, iron, transferrin saturation, total iron binding capacity) and the plasma concentrations of trace and ultratrace minerals (copper, manganese, molybdenum, selenium, zinc) and plasma retinol and alpha-tocopherol were in the reference ranges. Vitamin A intakes (r = 0.49, p < 0.05) and plasma retinol-binding protein concentrations (r = 0.42, p < 0.05) were positively correlated with plasma retinol concentrations at 3 mo of study. At 6 mo, concentrations of plasma transthyretin (r = 0.72, p < 0.01) and retinol-binding protein (r = 0.48, p < 0.05) were positively correlated with plasma retinol concentrations. At 6 mo, concentrations of plasma transthyretin (r = 0.52, p < 0.05) were positively correlated with retinol-binding protein concentrations. Phenex-1 supports normal mean iron status indices and mean concentrations of trace and ultratrace minerals, retinol, and alpha-tocopherol when fed in adequate amounts.

Micronutrients prevent cancer and delay aging

Approximately 40 micronutrients are required in the human diet. Deficiency of vitamins B12, folic acid, B6, niacin, C, or E, or iron, or zinc, appears to mimic radiation in damaging DNA by causing single- and double-strand breaks, oxidative lesions, or both. The percentage of the US population that has a low intake (< 50% of the RDA) for each of these eight micronutrients ranges from 2% to > or = 20%; half of the population may be deficient in at least one of these micronutrients. Folate deficiency occurs in approximately 10% of the US population, and in a much higher percentage of the poor. Folate deficiency causes extensive incorporation of uracil into human DNA (4 million/cell), leading to chromosomal breaks. This mechanism is the likely cause of the increased cancer risk, and perhaps the cognitive defects associated with low folate intake. Some evidence, and mechanistic considerations, suggest that vitamin B12 and B6 deficiencies also cause high uracil and chromosome breaks. Micronutrient deficiency may explain, in good part, why the quarter of the population that eats the fewest fruits and vegetables (five portions a day is advised) has approximately double the cancer rate for most types of cancer when compared to the quarter with the highest intake. Eighty percent of American children and adolescents and 68% of adults do not eat five portions a day. Common micronutrient deficiencies are likely to damage DNA by the same mechanism as radiation and many chemicals, appear to be orders of magnitude more important, and should be compared for perspective. Remedying micronutrient deficiencies is likely to lead to a major improvement in health and an increase in longevity at low cost. Aging appears to be due, in good part, to the oxidants produced by mitochondria as by-products of normal metabolism. In old rats mitochondrial membrane potential, cardiolipin levels, respiratory control ratio, and overall cellular O2 consumption are lower than in young rats, and the level of oxidants (per unit O2) is higher. The level of mutagenic aldehydes from lipid peroxidation is also increased. Ambulatory activity declines markedly in old rats. Feeding old rats the normal mitochondrial metabolites acetyl carnitine and lipoic acid for a few weeks, restores mitochondrial function, lowers oxidants to the level of a young rat, and increases ambulatory activity. Thus, these two metabolites can be considered necessary for health in old age and are therefore conditional micronutrients. This restoration suggests a plausible mechanism: with age-increased oxidative damage to proteins and lipid membranes causes a deformation of structure of key enzymes, with a consequent lessening of affinity (Km) for the enzyme substrate; an increased level of the substrate restores the velocity of the reaction, and thus restores function.

Heterozygosity for the C282Y mutation in the hemochromatosis gene is associated with increased serum iron, transferrin saturation, and hemoglobin in young women: a protective role against iron deficiency?

Genetic hemochromatosis (GH) is the most common autosomal-recessive disorder (1 in 300 in populations of Celtic origin). Homozygosity for a C282Y mutation in the hemochromatosis (HFE) gene is the underlying defect in ∼80% of patients with GH, and 3.2–13% of Caucasians are heterozygous for this gene alteration. Because the high frequency of this mutation may result from a selection advantage, the hypothesis was tested that the C282Y mutation confers protection against iron deficiency in young women. To address this question the genotype of codon 282 was determined in a cohort of 468 unrelated female healthcare workers, ages 18–40 years. In all study participants, a complete blood count was obtained, and erythrocyte distribution width, serum iron, transferrin, transferrin saturation, and ferritin were measured. Two individuals were homozygous for the C282Y mutation, 44 were heterozygous, and 416 were homozygous for the wild-type allele. Heterozygous women had significantly higher values for hemoglobin (P = 0.006), serum iron (P = 0.013), and transferrin saturation (P = 0.006) than women homozygous for the wild-type allele. Our data provide evidence for a protective role of the C282Y mutation in the HFE gene against iron deficiency in young women and suggest that a more efficient utilization of nutritional iron may have contributed to the high prevalence of the mutation in Caucasian populations.

Meatless diets in female athletes: a red flag

Physically active adolescent girls and young women may eliminate meat from their diets to achieve or maintain low body weight. By doing so, they risk developing protein, iron, and zinc deficiencies. Further, meatless diets in this population may signal the possibility of amenorrhea and/or disordered eating, with the attendant risk of osteoporosis. Educating young women and their parents and coaches regarding the risks of a meatless diet and using the preparticipation exam to screen for these problems can promote preventive measures.

Evaluation of the gastrointestinal tract in premenopausal women with iron deficiency anemia

PURPOSE

Iron deficiency anemia is often attributed to menstrual blood loss in premenopausal women. The aims of this study were to determine the diagnostic yield of endoscopy and to evaluate the clinical outcome in these women.

METHODS

Charts, endoscopy records, and pathology reports were reviewed in consecutive premenopausal women with documented iron deficiency anemia who were referred for diagnostic endoscopy. Follow-up was obtained by telephone contact and review of medical records.

RESULTS

Endoscopy revealed a clinically important lesion in 23 (12%) of 186 patients. An upper gastrointestinal source was identified in 12 patients, most commonly due to gastric cancer (3%) or peptic ulcer disease (3%). A colonic lesion was detected in 11 patients, with colon cancer in six (3%). No patient had a lesion identified in both the upper and lower gastrointestinal tract. Small bowel biopsies and radiography were normal in all patients in whom they were obtained. Independent predictors for having a gastrointestinal lesion identified by endoscopy include a positive fecal occult blood test, a hemoglobin of <10 g/dL, and abdominal symptoms. Long-term follow-up data suggested a favorable prognosis, and iron deficiency anemia resolved with appropriate therapy in nearly all patients.

CONCLUSIONS

Endoscopy yields important findings in premenopausal women with iron deficiency anemia, which should not be attributed solely to menstrual blood loss.

Diagnostic utility of serum transferrin receptors measurement in assessing iron status

Serum transferrin receptors (TfR) are a sensitive index of tissue iron availability, increasing progressively in response to functional iron deficiency. Unlike conventional laboratory tests of iron status, serum TfR are unaffected by underlying acute or chronic infection. Therefore, serum TfR measurement is particularly promising for evaluation of iron status when iron deficiency is simultaneously present with overt or subclinical infection or inflammation--a scenario often seen in patients seeking medical care, in elderly persons, and in persons living in developing countries. This test is also promising for assessment of iron status in pregnancy because it is not confounded by gestational effects. With the exception of conditions associated with markedly enhanced erythropoiesis which can increase TfR independently (e.g., megaloblastic anemia, thalassemia), serum TfR determination is a specific test of iron status. Serum TfR measurement is also reliable; a single, small amount of blood sample is adequate for its accurate determination. These sensitivity, specificity, and reliability characteristics of serum TfR measurement enable it to enhance confidence in iron status assessment in complex situations with the standard repertoire of laboratory tests.

Iron status of Asian children aged 2 years living in England

Haemoglobin and ferritin values were analysed in blood from 1057 children, aged 2 years, of Asian parents living in England. Children who had thalassaemia trait or a current/recent infection were excluded. Twenty nine per cent of Pakistani, 25% of Bangladeshi, and 20% of Indian children had haemoglobin < 110.0 g/l. The recent national diet and nutrition survey of preschool children found a prevalence of 12% of 2 year olds with haemoglobin < 110.0 g/l. No single factor accounted for more than a small proportion of the variance in haemoglobin and ferritin values, but the most significant factors that had a negative effect on iron status included the amount of cows' milk consumed, the use of a baby bottle, and mother's place of birth being outside of the UK. Taking vitamin or iron supplements was positively associated with iron status in one or more of the three groups.

The remedying of iron deficiency: what priority should it have?

Fe deficiency is considered to be the commonest of nutritional deficiencies worldwide. Adverse effects are stated to include lower growth rate and impaired cognitive scores in children and poor pregnancy outcome and lower working capacity in adults. In the present review, Fe intake, stores of the element, the magnitude of deficiencies and the benefits from interventions, as reflected in the results of clinical trials, are discussed. Because of inadequacies of knowledge in numerous respects, more information is needed regarding the extent to which clinical trials relate to public health realities, before introducing regional or national supplementation programmes. While Fe supplements are needed in certain groups, and in particular regions, increased dietary intakes could be supplied by food fortification, as well as by individual improvements in intake.