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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
31

Food-based strategies to improve dietary iron intake and biochemical iron status in 12-24 month old New Zealand children

Szymlek-Gay, Ewa Anna, n/a January 1900 (has links)
Adequate nutrition is fundamental to optimal physical and cognitive growth in the second year of life. Toddlers, however, are particularly vulnerable to poor nutrition due to their high nutrient needs in relation to their body size and energy intakes. Nutrient-dense diets are therefore essential during this period. However, no practical quantitative food-based dietary guidelines directed at this age group are available to help caregivers choose nutrient-rich foods for their toddler. Such guidelines are needed not only to ensure adequate intakes of all nutrients during the period of dietary transition from infant to family foods, but also to emphasise intakes of nutrients for which toddlers are at particular risk of deficiency. Biochemical evidence suggests that iron nutrition requires special attention in New Zealand toddlers. The overall aim of this thesis was to design and assess the efficacy of practical food-based strategies for toddlers to ensure optimal nutritional status of 12-24 month old New Zealand children, with a specific focus on iron nutrition. To achieve these overall aims, the research was carried out in three stages. In the first stage, secondary data analysis of food intake data for New Zealand toddlers identified the foods commonly consumed by New Zealand toddlers, the serving sizes and frequency of consumption of these foods, and the nutrients that New Zealand toddlers are at risk of consuming in suboptimal amounts. The food intake data were obtained from 3-day weighed food intakes that had been collected on non-consecutive days in an earlier community-based cross-sectional survey of 188 randomly selected non-breastfeeding 12-24 month old urban South Island New Zealand children. In addition to describing the food consumption patterns of New Zealand toddlers, the secondary data analysis also identified that nearly 40% of New Zealand toddlers were at risk of suboptimal iron intakes. The results of these analyses were used in the second stage of the thesis to develop three food-based strategies. To do this a 4-phase approach based on linear and goal programming was used to design and hypothetically evaluate three sets of food-based strategies for 12-24 month old non-breastfeeding New Zealand children, and to identify the key problem nutrients for each set of strategies. The three sets of strategies were based on: (1) all foods consumed by toddlers including iron-fortified infant and toddler foods, (2) family foods only, or (3) family foods that are not fortified with iron. The mathematical modelling confirmed that iron was the key problem nutrient in the diets of New Zealand toddlers. The analysis showed that only food-based strategies that included a recommendation for the replacement of non-fortified cow�s milk with an iron-fortified toddler milk (500 mL), i.e. strategy set 1, achieved the Australian-New Zealand Recommended Dietary Intakes for all nutrients, including iron. In fact, inclusion of a recommendation for a substantially increased consumption of flesh foods was identified as the only possible alternative to the iron-fortified toddler milk recommendation for improving iron nutrition in New Zealand toddlers. Although the set of strategies including this flesh food recommendation did not provide as much total iron as those including the iron-fortified toddler milk recommendation, the bioavailability of the iron is likely to be greater because flesh foods provide highly bioavailable haem iron (red meat being a particularly rich source) and have an enhancing effect on the absorption of non-haem iron. The two key recommendations for achieving New Zealand toddlers� iron needs were, therefore, a recommendation to consume an iron-fortified toddler milk and a recommendation to consume substantial amounts of red meat. In the third stage, the efficacy of an increased intake of red meat or the use of an iron-fortified milk for improving biochemical iron status in healthy non-anaemic 12-20 month old New Zealand children was investigated in a 20-week partial double-blind randomised placebo-controlled intervention trial. The study also examined the effect of these two interventions on dietary iron intakes and growth, and investigated the association between the amount of meat consumed and biochemical iron parameters. Participants (n=225) were assigned to one of three groups: Meat Group (n=90), Fortified Milk Group (n=45), or Placebo Group (n=90). Children in the Meat Group were encouraged to consume two red meat dishes per day (~ 2.6 mg of iron). In the Fortified Milk Group and Placebo Group, the children�s regular milk was replaced with iron-fortified cow�s milk (1.5 mg of iron per 100 g of prepared milk), or non-fortified cow�s milk (< 0.1 mg of iron per 100 g of prepared milk), respectively. Geometric mean dietary iron intakes (95% CI) increased from 4.7 (4.1, 5.3) to 5.3 (4.7, 6.0) mg per day in the Meat Group (P=0.007), and from 4.3 (3.7, 5.0) to 10.4 (9.0, 12.2) mg per day in the Fortified Milk Group (P<0.001). These increased iron intakes differed significantly from the Placebo Group (both P<0.001), which declined from 5.1 (4.5, 5.7) to 4.6 (4.1, 5.2) mg per day during the intervention (P=0.047). Over 20 weeks, adjusted geometric mean serum ferritin concentration increased by 44% (95% CI: 14%, 82%) in the Fortified Milk Group (P=0.002), tended to decrease in the Placebo Group (14% decrease (95% CI: -27%, 1%; P=0.063)), and did not significantly change in the Meat Group (10% increase (95% CI: -7%, 30%; P=0.241)). However, because iron status declined in the Placebo Group, both groups fared significantly better than the Placebo Group: serum ferritin concentration at 20 weeks was 68% (95% CI: 27%, 124%; P<0.001) greater in the Fortified Milk Group than in the Placebo Group, and 29% (95% CI: 2%, 63%; P=0.033) greater in the Meat Group than in the Placebo Group. There were no intervention effects on haemoglobin or serum transferrin receptor concentration. The cross-sectional analysis showed that a daily intake of 1 g of red meat was associated with 0.65% (95% CI: 0.18%, 1.11%; P=0.007) higher serum ferritin concentration. No adverse effects of the interventions on the toddlers� growth were detected. In conclusion, this thesis shows that food-based strategies can be designed that, if adhered to, should ensure adequate iron status in New Zealand toddlers. Although both the iron-fortified milk recommendation and the increased red meat recommendation are likely to prevent the decline in body iron stores that can occur during the second year of life, only consumption of iron-fortified milk can successfully increase iron stores. Therefore, food-based strategies for New Zealand toddlers will need to include a recommendation that encourages the consumption of foods developed specifically for toddlers that are fortified with iron.
32

Iron status and behavioral factors relative to dietary source of protein intake among female athletes at Virginia Tech /

Garman, Lucy S., January 1992 (has links)
Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 113-120). Also available via the Internet.
33

The Copper and Iron Intake and Hemoglobin of Student Nurses

Badgett, Lula Mae Starnes January 1948 (has links)
The object of this study is to determine the effect, if any, of the copper and iron intake upon the hemoglobin levels of student nurses on self-chosen diets.
34

Iron status and behavioral factors relative to dietary source of protein intake among female athletes at Virginia Tech

Garman, Lucy S. 23 December 2009 (has links)
Sixty-two female athletes at Virginia Tech participated in an investigation to compare iron status among those whose primary source of dietary protein was red meat (M), lacto-ovovegetarian (V), or poultry and fish (PF). Subjects' blood was collected three times over the six-month study period and analyzed for hemoglobin, hematocrit, serum iron, transferrin saturation, total iron~binding capacity, serum ferritin, free erythrocyte protoporphyrin, mean corpuscular volume, and red blood cell count. Means for all dietary groups were within normal limits for all blood variables. There were no significant differences among the dietary groups for any of the hematological parameters. Six of the sixty-two subjects were found to be in stage 1 iron deficiency; two from Group M, one from Group V, and three from Group PF. None of the subjects was in stage 2 or 3 iron deficiency. Subjects completed two 3-day dietary recalls which were analyzed for nutrient content. Group M consumed a significantly greater percent of kcals from protein than Group V and significantly more grams of protein than both Groups V and PF. There were no significant differences among the groups for intake of iron; however, only Group H consumed the current RDA for iron for adult women. Three subjects from each dietary group were interviewed to identify factors considered most important in the adoption of their dietary patterns. Primary factors identified were: Group H; habit, taste preference, and health; Group Vi athletic performance and ethical treatment of animals, and Group PF; taste preference and health. Iron status in this population does not appear to be affected by source of dietary protein. / Master of Science
35

Molecular analysis of genes involved in iron overload implicated in oesophageal cancer

Human, Veronique 03 1900 (has links)
Thesis (MSc (Genetics))--University of Stellenbosch, 2007. / Oesophageal cancer is a disease characterised by a disproportionate presentation in certain ethnic groups, with squamous cell carcinoma (SCC) occuring more often in Blacks and adenocarcinoma (ADC) being more prevalent in Caucasians. Several factors have been attributed to the development of OC, including an excess of iron (leading to enhanced tumour growth), oesophageal injury and chronic inflammation. The main aim of this study was to establish the mutation spectrum of six genes (including HFE, HMOX1, SLC40A1, HAMP, CYBRD1 and HJV) involved in iron metabolism, in the Black South African OC population. The patient cohort comprised of 50 (25 male and 25 female) unrelated patients presenting with SCC of the oesophagus, with the control group consisting of 50 unrelated, healthy population-matched individuals. The mutation detection techniques employed included polymerase chain reaction (PCR) amplification, heteroduplex single-stranded conformational polymorphism (HEX-SSCP) analysis, restriction fragment length polymorphism (RFLP) analysis and bi-directional semi-automated DNA sequencing analysis of variants identified.
36

Inflammation, immune suppression, and iron status in endurance athletes and the effects of antioxidant supplementation

Hopkins, Dawn Marie Weseli 19 February 2003 (has links)
During extreme exercise, athletes experience increased inflammation that is similar to the acute phase response. Endurance athletes, distance runners in particular, are also more susceptible to compromised iron stores. This study evaluated inflammation, immune function and iron status in athletes completing a 50K ultramarathon. Twenty-two well-trained distance runners, 11 males and 11 females, were randomized in a double blind manner into--1) those who consumed 300 mg vitamin E and 1000 mg vitamin C (500 mg twice daily) or 2) placebos--for six weeks before and one week following a 50K ultramarathon race. Blood samples were obtained on 13 separate occasions throughout the study: before supplementation, during supplementation, the day before the race, pre-race, mid-race, immediately post-race, 2 hours following the race, and daily for six days following the race. Plasma levels of ascorbic acid and ��-tocopherol were measured by HPLC with electrochemical detection. Inflammatory cytokines, interleukin-6 (IL-6), tumor necrosis factor-�� (TNF-��), and interleukin-1�� (IL-1��) were measured using standard clinical assays. Each subject recorded immune function in an activity log and incidence of illness was tabulated as number of days ill. Ferritin was measured by enzyme immunoassay. Hemoglobin, hematocrit, and total-iron binding capacity (TIBC) and serum total iron were analyzed by standard procedures. Plasma concentrations of ascorbic acid and ��-tocopherol increased significantly in supplemented subjects (p<0.0001). Although the ultramarathon race elicited an inflammatory response, antioxidant supplementation did not alter the responses of IL-6 and TNF-��, which both increased from pre-race to mid-race, post- and post-2 h (Scheffe post-hoc analysis, p<0.0001) and returned to pre-race concentrations by 1 day after the race. Male supplemented subjects had lower IL-1�� concentrations compared to females consuming the supplement or to males consuming the placebo (ANCOVA, gender/time/treatment interaction; p<0.01) at mid-race (p<0.05 females, p<0.005 males), post 1 and 2 days (all p<0.002). Males had significantly higher ferritin levels than the female subjects (ANOVA, p<0.0001); supplementation resulted in lower ferritin concentrations at post-5 days (p<0.02, ANCOVA treatment time interaction, p<0.005). Supplementation did not reduce the days illness among those consuming antioxidants compared to those consuming the placebos. Ferritin not only increases during inflammation, it also is a measure of iron stores. Females had significantly lower levels of iron than the male subjects for each of the iron parameters measured (hemoglobin and hematocrit both p<0.0001, ferritin p<0.001, TIBC p<0.02) excluding serum total iron. The ferritin concentrations measured in the women were indicative of depleted iron stores (<12 ��g/l), and antioxidant supplementation increased hematocrit levels in the female subjects (p<0.05). This investigation indicates that female distance runners need to be aware of an increased susceptibility to iron depletion compared to their male counterparts. Antioxidant supplementation improved hematocrit levels (p<0.05) among female runners and may improve iron status among females with depleted stores. Although other investigations have suggested that antioxidant vitamins decrease exercise induced inflammation, no profound benefit of supplementation was found in this investigation though a response similar to the acute phase response was elicited by the ultramarathon race. Improvements in IL-i and ferritin in response to antioxidant supplementation may indicate that the supplementation was beneficial, but more research is needed to draw definitive conclusions. / Graduation date: 2003
37

Iron Status of Students at North Texas State University

Orgeron, Judy 05 1900 (has links)
Hematocrit, serum-iron and iron-binding capacity were used to test the iron status of a sample of fifty-six volunteer students. Subjects completed a questionnaire to examine whether a correlation exists between iron status and iron knowledge. The sample, including 20 males and 36 females, consisted of ten nutrition majors , eight biology majors, thirty-eight other majors, and eight vegetarians. The four measures revealed that a high prevalence of iron deficiency did not exist in this student population. Other findings: sex and iron status are not related; no correlation exists between iron knowledge and iron status; and vegetarians have an iron status comparable to that of non-vegetarians.

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