The objectives of the present study in rural Nepali pregnant women living in the terai were: 1) to identify the risk factors of severe anemia and investigate whether risk factors for anemia without iron deficiency, iron deficiency without anemia and iron deficiency anemia (IDA) were different; 2) to examine the effect of vitamin A supplementation, alone or combined with iron, on hemoglobin (Hb) and soluble transferrin receptor (sTfR); and 3) to identify the risk factors of low birth weight (LBW) and preterm delivery, focusing on maternal Hb concentrations. The prevalence of severe anemia (Hb < 8.0 g/dl) in this population (n = 3531) was 4.2% and that of iron deficiency was 31%. Logistic regression analyses indicated that risk factors of severe anemia included hookworm infestation, impaired dark adaptation, lack of iron supplement intake, a diet low in heme iron and malnutrition manifested by thinness and short stature. These same factors differed among non-iron-deficient anemic, iron deficient non-anemic, and iron-deficient anemic pregnant women. We found a significant positive correlation between Hb and retinol concentrations (Pearson r = 0.212, P < 0.0001) and one fourth of our anemic subjects were also vitamin A deficient. There was no evidence that vitamin A alone significantly increased Hb and decreased the prevalence of anemia (n = 498). However, vitamin A, when given together with iron, had an added beneficial effect on Hb but not sTfR. In addition, women with initially compromised iron status benefited more from iron and vitamin A supplementation. The prevalence of LBW and preterm delivery was 22% and 20%, respectively (n = 915). There was an increased risk of LBW associated with short stature, thinness and impaired dark adaptation. The association between Hb measured during the second trimester and risk of LBW had a U-shaped distribution, with risk increasing significantly with Hb < 8.0 g/dl. Based on our findings, we recommend that Hb is evaluated during the second trimester as an indicator of increased LBW risk. While vitamin A supplementation to all pregnant women is recommended, routine supplementation of iron and deworming during pregnancy are essential.

Thesis (MAppSc (Medical Laboratory Science)) --University of South Australia, 1992

Corrigenda tipped to title page. / Includes bibliographical references (leaves 313-353). / xxvii, 353 leaves : ill. (some col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Investigates the iron status and dietary intakes in 6-24 month old children in Australia and Ghana and assesses the effects of dietary calcium on intestinal iron absorption. The true prevalence of non-anaemic iron deficiency (NAID) and iron deficiency anaemia (IDA) and dietary intakes in infants and toddlers from a broad socio-economic background were assessed by haematological and biochemical parameters, semi-quantitative diet recall and anthropometric measurements. The high prevalence of iron deficiency and anaemia found in Australian and Ghanaian children can be attributed to the low intake of bioavailable iron in weaning diets which are often ingested with large amounts of calcium. While calcium has been shown to inhibit the absorption of iron, its mechanism of interaction with iron absorption at the intestinal level is not known. The rat was used as an experimental model to investigate the effects of dietary calcium on duodenal iron uptake. The results indicate there is a critical period during weaning when the consumption of high dietary calcium with low iron can retard growth potential. Dietary calcium significantly inhibits non-haem iron absorption at the intracellular level by up-regulating villus enterocyte ferritin concentrations under iron deficiency conditions. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Science, 1998

Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Science, 1998? / Corrigenda tipped to title page. Bibliography: leaves 313-353.

Thesis (M.S.)--University of Michigan, 1976.

Thesis (D.P.H.)--University of Michigan, 1994.

Thesis (M.S.)--University of Michigan, 1976.

Thesis (D.P.H.)--University of Michigan, 1994.

Corrigenda tipped to title page. Bibliography: leaves 313-353. This study investigated the iron status and dietary intakes in 6-24 month old children in Australia and Ghana and assessed the effects of dietary calcium on intestinal iron absorption. The true prevalence of non-anaemic iron deficiency (NAID) and iron deficiency anaemia (IDA) and dietary intakes in infants and toddlers from a broad socio-economic background were assessed by haematological and biochemical parameters, semi-quantitative diet recall and anthropometric measurements. The high prevalence of iron deficiency and anaemia found in Australian and Ghanaian children can be attributed to the low intake of bioavailable iron in weaning diets which are often ingested with large amounts of calcium. While calcium has been shown to inhibit the absorption of iron, its mechanism of interaction with iron absorption at the intestinal level is not known. The rat was used as an experimental model to investigate the effects of dietary calcium on duodenal iron uptake. The results indicate there is a critical period during weaning when the consumption of high dietary calcium with low iron can retard growth potential. Dietary calcium significantly inhibits non-haem iron absorption at the intracellular level by up-regulating villus enterocyte ferritin concentrations under iron deficiency conditions.

In order to examine the effects of prelatent/latent iron deficiency on physical work capacity and selected muscle enzyme activities, forty female subjects were studied before and after eight weeks of supplementation with either oral iron or a matching placebo. Initially, female volunteers engaged in regular endurance running were screened for iron deficiency by blood analysis (serum ferritin and hemoglobin). Forty non-anemic subjects with deficient iron stores underwent physiological and anthropometric tests to obtain a comprehensive profile. The specific physical work capacity tests were alactic and lactacid power on the Wingate cycle ergometer test, lactacid capacity on the anaerobic speed test, anaerobic (ventilatory) threshold using gas exchange variables, V0₂ max. and the max. treadmill velocity during the V0₂ max. test. Muscle biopsy samples pre-, and post- treatment were assayed for citrate synthase and alpha-glycerophosphate dehydrogenase activity. Treatment was oral iron supplementation (320 mg ferrous sulfate = 100 mg elemental iron taken as SLOW-Fe® twice a day) or a matching placebo. The subjects were randomly assigned to one of the treatment groups and a double-blind method of administration of the supplements was used. It was hypothesized that work capacity would be enhanced following oral iron supplementation, possibly due to the repletion of iron containing oxidative enzymes important in energy production. Results could not strongly support this hypothesis with the difference between the two groups on the work capacity and enzyme activity variables being statistically nonsignificant. Serum ferritin values rose from a mean of 12.4+4.5 to 37.7+19.7 ngml⁻¹ for the experimental group and 12.2±4.3 to 17.2±8.9 for the controls; (p=0.0025). Hemoglobin levels remained fairly constant for both treatment groups; 13.4±0.6 to 13.5±0.5 gdl⁻¹ (experimental), and 13.0±0.6 to 13.1+0.5 (control); (p=0.6). Pre to post values on the work capacity variables, experimental vs control respectively were: Alactic power, 8.8 to 8.4 watts-kg⁻¹ body wt. vs 8.4 to 8.2; lactacid capacity, 6.9 to 6.9 watts-kg⁻¹ body wt. vs 7.0 to 6.0; anaerobic speed test, 41.3 to 45.1 seconds vs 43.7 to 44.8; anaerobic threshold, 7.4 to 7.5 mileshour⁻¹ vs 7.2 to 7.2; V0₂ max, 51.3 to 52.7 ml-kg⁻¹ min⁻¹ vs 50.6 to 50.6; max velocity during V0₂ max, 9.8 to 9.8 mileshour⁻¹ vs 9.6 to 9.5. Except for alactic power, the change in work capacity favored the iron treated group. Noting this trend, further study may be warranted. Prelatent/latent iron deficiency appeared not to depress the activities of the two enzymes measured. Cytoplasmic alpha-glycerophosphate dehydrogenase activity rose from 0.066 to 0.085 units for the experimental group (p=.58) vs .058 to .066 for the control group and citrate synthase activity changed from 0.047 to 0.048 (experimental) vs 0.039 to 0.042 (control). It can be concluded that eight weeks of iron supplementation to prelatent/latent iron deficient, physically active females does not significantly enhance work capacity nor the activity of 2 oxidative muscle enzymes (citrate synthase and cytoplasmic alpha-glycerophosphate dehydrogenase). Within the limitations of this study the presence of a serum ferritin below 20 ng-ml⁻¹ does not pose a significant handicap to anaerobic or aerobic capacity. / Graduate and Postdoctoral Studies / Graduate