Search

Background: Oral iron supplementation with ferrous sulfate (FeSO₄) at dosage levels suggested by the international guidelines poses a safety hazard to young children with malaria. Exposure to loosely bound iron in the circulation has been advanced as a potential factor. Objective: To evaluate the kinetics of circulating concentrations of plasma iron and non-transferrin-bound iron (NTBI) in response to oral iron administration in healthy adults. Methods: Plasma samples were collected at 90-minute intervals over a period of 270 minutes from 10 healthy Guatemalan men after oral administration of water or 100 mg of iron from each of three iron compounds: FeSO₄, sodium iron ethylenediaminetetraacetic acid (NaFeEDTA), and iron polymaltose. The four tests were administered in an individually randomized sequence. Serum iron concentration was measured spectrophotometrically by the ferrozine method, and NTBI concentration was measured by a fluorometric competitive binding assay. The kinetic response and the maximal and cumulative changes in circulating concentrations of the biomarkers of interest were compared. Results: Serum iron and NTBI responses to oral administration of FeSO₄ were significantly greater than responses to plain water or the other two iron compounds. NTBI concentrations after NaFeEDTA or iron polymaltose ingestion were not different from those determined after water intake. Conclusions: Administration of two iron compounds of proven bioavailability, but with complex absorption characteristics, is associated with a negligible NTBI response, potentially mitigating the safety concerns associated with iron supplementation in malarial areas. [ABSTRACT FROM AUTHOR]

Background: Urinary biomarkers are used in assessment of severe, clinical oxidative stress. Little is known, however, about their diagnostic value within the normative range.Objective: To evaluate the response of urinary thiobarbituric acid reactive substances (TBARS) and 8-hydroxy-2-deoxyguanosine (8-OHdG) as indicators of systemic oxidation in response to short-term oral iron and antioxidant supplementation.Methods: Five healthy adult men participated in the pilot study phase and 12 in the definitive intervention trial. For 7 days each, separated by 12-day washouts, the subjects received different treatment regimens, consisting of 120 mg of iron, 120 mg of iron in refined palm oil, and 120 mg of iron in palm oil combined with one of the two doses of Carotino Tocotrienol Carotene Mixed Concentrate (CTCMC). Creatinine-normalized urinary TBARS and 8-OHdG concentrations were quantified in samples taken from subjects with and without active supplementation. Temporal and correlative associations between TBARS and 8-OHdG were explored.Results: Daily intake of supplemental iron failed to produce any increment in urinary excretion of TBARS or 8-OHdG. However, a significant within-individual correlation between the urinary biomarkers was observed (Spearman r = 0.697, p < .0001, n = 466). Both doses of CTCMC significantly lowered urinary excretion of both oxidation indicators.Conclusions: Despite the lack of effect of oral iron on the biomarkers of systemic oxidation, they show a strong and significant mutual association within the nonpathological range of oxidative stress in healthy male adults. [ABSTRACT FROM AUTHOR]

Background: The World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) 1997 recommendations for cancer prevention were meant to apply to children as well as adults.Objective: To assess the concordance of behaviors and body composition of urban Guatemalan schoolchildren with the tenets of the WCRF/AICR 1997 recommendations.Methods: A survey was conducted involving determination of 24-hour consumption of foods and beverages by a pictorial registry and height and weight measurements in 355 third- and fourth-grade schoolchildren in the western highland city of Quetzaltenango, Guatemala. Based on a previous, exhaustive parsing of the population goal recommendations of the WCRF/AICR 1997 report, 25 subcomponents were identified. Eleven could be evaluated with the survey data collected. Adult population criteria could be applied in seven, whereas four components had unique criteria adapted to this juvenile survey setting.Results: The study sample was concordant on seven components-nutrient adequacy, total variety of foods consumed, plant-based diets, body mass index, vegetable and fruit intake, limitation of red meat consumption, and limitation of total fat consumption, and nonconcordant on four-variety of fruits and vegetables consumed, variety of starchy foods consumed, total intake of starchy foods, and limitation of sugar consumption.Conclusions: Educational and public health actions need to be conceived and implemented to further improve the rate of concordance of these 11 components with the WCRF/AICR 1997 recommendations for cancer prevention. [ABSTRACT FROM AUTHOR]

The vulnerability of large segments of Asia's population to micronutrient deficiency is more a consequence of cultural evolution and demography than of economic inequities. We evolved in a hunter-gatherer lifestyle with vigorous energy expenditure, wide dietary variety and a nutrient-dense diet (meat, viscera), and wound up 10,000 years ago as agriculturalists cultivating cereal and tuber crops for 70% of our dietary calories. Obtaining rice, maize and wheat is less energy intensive than needed for hunters' fare, while grains are distinctly less rich in available vitamins and minerals. Recurrent infectious episodes, transmitted in crowded societies, further deplete micronutrient nutriture. A fast-track option to address historically unprecedented life conditions includes chemical- or bio-fortification of ubiquitous condiments or widely consumed staples. With little or no change in habitual eating individuals will consume recommended micronutrient intakes and uptakes. Generous intakes of nutrients such as vitamin A and zinc counteract the adverse environmental effects on quality of life and survival in poverty situations. One size may not fit all, and over-consumption of certain micronutrients in heterogeneous societies is to be avoided. For the rice bowl to support the descendants of the caveman in the third millennium requires both imagination and technological ingenuity. [ABSTRACT FROM AUTHOR]

BACKGROUND: Deuterated retinol dilution (DRD) gives quantitative estimates of total body stores of vitamin A. OBJECTIVES: In elderly people, we studied 1) the time when an oral dose of deuterated vitamin A equilibrates with body stores, 2) whether serum ratios of deuterated to nondeuterated retinol (D:H) at 3 or 6 d postdosing predicted body stores, and 3) the ability of DRD to detect changes in the size of the body vitamin A pool. DESIGN: A 10-mg oral dose of [2H4]retinyl acetate was administered to 60-81-y-old Guatemalans (n = 47); percentage enrichment of serum retinol with deuterated retinol was determined at 1-3 time points per subject at 3, 6, 7, 14, 20, 21, and 54 d. In subjects from whom blood was obtained at 3 and 21 d (n = 15) and at 6 and 20 d (n = 9), total body stores were calculated by using the formula of Furr et al (Am J Clin Nutr 1989;49:713-6) with 21- or 20-d data and correlated with serum D:H at 3 or 6 d postdosing. Nine subjects received diets containing 982+/-20 microg RE (x+/-SEM) plus 800 microg RE as retinyl acetate supplements for 32 d. DRD, serum retinol, and relative dose response were used to assess vitamin A status before and after the intervention. RESULTS: Deuterated retinol equilibrated with the body pool by 20 d postdosing. Vitamin A supplementation for 32 d increased body stores, although unexplained exaggerated increases were seen in some subjects. An inverse linear relation was found between estimates of body stores and serum D:H at 3 d postdosing (r = -0.75, P = 0.002); at 6 d postdosing, the correlation was weaker. CONCLUSIONS: DRD can detect changes in total body stores of vitamin A, although factors affecting serum D:H need to be elucidated. Serum D:H 3 d postdosing might be used as an early indicator of total body stores of vitamin A, although a predictive equation will need to be developed. Copyright (c) 1999 American Society for Clinical Nutrition [ABSTRACT FROM AUTHOR]

The use of discretionary salt, which is salt added during cooking and at the table, as a suitable vehicle for iodine intake was assessed by measuring salt consumption using the lithium-marker technique in rural areas of Guatemala and Benin. In both countries, we studied boys aged 6-12 y and their mothers. Subjects used lithium-labeled salt after all unlabeled salt was removed from their households. In Guatemala, 24-h urine samples for 9 mother-son pairs were collected at baseline and on days 7, 8, and 9 during the use of lithium-labeled salt. Total maternal salt intake averaged 5.2 +/- 1.7 g/d (mean +/- SD), of which 77 +/- 24% came from discretionary sources, whereas Guatemalan boys consumed 1.8 +/- 0.6 g salt/d, of which 72 +/- 12% came from discretionary sources. In Benin, urine collection from 13 mother-son pairs took place at baseline and on days 5 and 7. Beninese mothers had a total salt intake of 9.0 +/- 2.9 g/d and their sons had an intake of 5.7 +/- 2.8 g/d; discretionary salt contributed 52 +/- 14% and 50 +/- 13%, respectively, of total salt consumed. Therefore, fortification of household salt appears to be an appropriate method of controlling iodine deficiency in both countries, although fortification of other salt sources could be considered in Benin. Copyright (c) 1998 American Society for Clinical Nutrition [ABSTRACT FROM AUTHOR]

OBJECTIVES: The prevalence of vitamin A deficiency has traditionally been assessed through xerophthalmia or biochemical surveys. The cost and complexity of implementing these methods limits the ability of nonresearch organizations to identify vitamin A deficiency. This study examined the validity of a simple, inexpensive food frequency method to identify areas with a high prevalence of vitamin A deficiency. METHODS: The validity of the method was tested in 15 communities, 5 each from the Philippines, Guatemala, and Tanzania. Serum retinol concentrations of less than 20 micrograms\dL defined vitamin A deficiency. RESULTS: Weighted measures of vitamin A intake six or fewer times per week and unweighted measures of consumption of animal sources of vitamin A four or fewer times per week correctly classified seven of eight communities as having a high prevalence of vitamin A deficiency (i.e., 15% or more preschool-aged children in the community had the deficiency) (sensitivity = 87.5%) and four of seven communities as having a low prevalence (specificity = 57.1%). CONCLUSIONS: This method correctly classified the vitamin A deficiency status of 73.3% of the communities but demonstrated a high false-positive rate (42.9%). [ABSTRACT FROM AUTHOR]