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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.
111

Concentrações séricas de vitamina D em lactentes saudáveis / Serum vitamin D concentrations in healthy infants

Almeida, Ane Cristina Fayão 26 January 2018 (has links)
Introdução: Uma elevada prevalência de deficiência de vitamina D (DVD) em crianças tem sido observada em todo o mundo, mas poucos são os estudos com relação ao estado nutricional da vitamina D (VD) em lactentes saudáveis. A principal causa da deficiência em crianças saudáveis é o aleitamento materno sem suplementação e a falta ou insuficiência de exposição solar. Objetivos: Determinar as concentrações séricas de VD e verificar sua associação com concentrações de paratormônio (PTH), fosfatase alcalina (FA), cálcio (Ca), fósforo (P) e albumina e uso da suplementação de VD em lactentes saudáveis com idades entre >= 6 e <= 24 meses atendidos em duas Unidades Básicas de Saúde do município de Ribeirão Preto, SP, Brasil. Métodos: Estudo transversal, observacional e analítico em que foram determinadas as concentrações séricas de 25 (OH)D, PTH, FA, Ca, P e albumina de 155 lactentes saudáveis. Informações sobre exposição solar, aspectos sociodemográficos das mães e características clínico-nutricionais dos lactentes foram obtidas por entrevistas com os responsáveis dos lactentes. Concentrações séricas de 25(OH)D maiores que 20ng/ml foram consideradas adequadas, entre 12 a 20ng/ml insuficientes e < 12ng/ml deficientes. Resultados: Dez lactentes (6,5%, Intervalo de Confiança 95% 3,5-11,4) apresentaram insuficiência de VD e nenhum apresentou DVD. Nenhuma alteração nas concentrações séricas de P, Ca e albumina foram detectadas. Apenas um lactente apresentou aumento nas concentrações séricas de PTH e 35,5% dos lactentes apresentaram FA elevada, porém nenhum apresentou DVD ou insuficiência de VD. Não foram encontradas associações entre as concentrações séricas de 25(OH)D e as de FA, Ca e albumina. Houve associação entre concentrações séricas de 25(OH)D e PTH mesmo após ajuste para sexo, idade e Índice de Massa Corporal; também foi observada associação entre concentrações séricas de 25(OH)D e P apenas após o ajuste pelas covariáveis. Não foram verificadas associações entre insuficiência de VD, exposição solar e suplementação de VD. Conclusões: Uma baixa prevalência de concentrações insuficientes de 25(OH)D foi observada. Não foram encontradas associações entre as concentrações séricas de 25(OH)D e PTH, FA, Ca, P e albumina. Da mesma forma, não foram encontradas associações entre de concentrações séricas de 25(OH)D, exposição solar e suplementação de VD. / Introduction: A high prevalence of vitamin D deficiency (VDD) in children has been observed worldwide, but there are few studies on the nutritional status of vitamin D (VD) in healthy infants. The main cause of deficiency in healthy children is breastfeeding without supplementation and lack or insufficiency of sun exposure. Objective: To determine serum concentrations of VD and verify its association with parathyroid hormone (PTH) levels and use of VD supplementation in healthy infants aged >= 6 to <= 24 months attended at two Basic Health Units in Ribeirão Preto city, São Paulo, Brazil. Methods: A cross-sectional, observational and analytical study was performed in which were determined serum concentrations of 25 (OH) D, PTH, alkaline phosphatase (AP), calcium (Ca), phosphorus (P) and albumin of 155 healthy infants. Information of sun exposure, sociodemographic aspects of mothers and clinical and nutritional characteristics of infants were obtained through interviews with responsible for infants. Serum concentrations of 25(OH)D greater than 20ng / ml were considered adequate, between 12 to 20ng / ml insufficient and <12ng/ml, deficient. Results: Ten infants (6.5%, 95% Confidence Interval 3.5-11.4) presented VD insufficiency and none presented DVD. Only one infant had an increase in PTH serum concentrations and 35.5% of infants had high AP but none presented DVD or VD insufficiency. No changes in serum P, Ca and albumin concentrations were detected. No associations were found between serum concentrations of 25 (OH) D and AP, Ca and albumin. There was an association between serum concentrations of 25(OH)D and PTH even after adjusting for sex, age and body mass index; an association between serum concentrations of 25(OH)D and P was observed only after adjustment for covariates. There were no associations between VD insufficiency, sun exposure and VD supplementation. Conclusions: A low prevalence of insufficient concentrations of 25 (OH)D was observed. No associations were found between serum concentrations of 25 (OH)D and PTH, FA, Ca, P and albumin. Likewise, no associations were found between serum concentrations of 25 (OH)D, sun exposure and VD supplementation.
112

Investigation of vitamin B12 deficiency in ruminants : a thesis in fulfilment of the requirements for admission to the degree of Doctor of Philosophy of the University of Adelaide / by Wendy Babidge.

Babidge, Wendy Joy January 1993 (has links)
Includes bibliographical references (leaves 202-21). / 2 v. (xxiv, 409 leaves) : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Experiments were designed for the early detection of vitamin B12 deficiency in sheep and cattle. Metabolic indicators were examined in animals where deficiency was induced with either nitrous oxide (N2O) or by feeding diets of low cobalt content. Results showed that vitamin B12 dependent enzymes in the liver of ruminants appeared to be affected only at a late stage of deficiency. However changes in concentrations of metabolites of these pathways occured earlier. / Thesis (Ph.D.)--University of Adelaide, Dept. of Animal Sciences, 1994
113

Association between Serum Vitamin D Concentrations and Depression in the US Population: National Health and Nutrition Examination Survey, 1988-1994

Milone, Cristiana 14 September 2009 (has links)
Background: The role of nutrients in mental health has recently been recognized and investigated. Vitamin D has been known to play a role in a wide range of diseases, such as bone, cardiovascular, and autoimmune diseases, and cancers. Recently, its role in cognitive function and mental health has been reported. Vitamin D receptor and hydroxylases have been mapped throughout the brain, suggesting a role for vitamin D in brain tissue. An inverse association between vitamin D and depression was observed in European epidemiologic studies. There is a paucity of data on the association between vitamin D concentrations and depression in the U.S. population. Objective: The objective of this study was to investigate the association between serum vitamin D concentrations and depression in a large, nationally representative sample survey, the third National Health and Nutrition Examination Survey 1988-1994 (NHANES III). Methods: The study sample included 7970 adults, ages 15-39 years, who completed the Diagnostic Interview Schedule for depression and had vitamin D concentrations measured. SAS and SUDAAN statistical software packages were used in data analysis. Multivariate logistic regression was used to estimate the likelihood of having depression in vitamin D deficient persons in relation to vitamin D sufficient persons, after taking several confounding variables into consideration. Significance was set at α < 0.05. Results: The prevalence of vitamin D deficiency was higher in women than in men (24 % vs. 15%), higher in African-Americans than in whites (60% vs. 10%), higher in people living in metropolitan rather than in rural areas (25% vs. 14%), and higher in subjects below the poverty threshold than in higher income subjects (29% vs. 14%). The prevalence of vitamin D deficiency increased as BMI increased. The diagnostic variables for depression did not show an association with vitamin D deficiency after adjusting for several confounding factors. However, subjects having a depressive episode at the time of the interview, were significantly more likely to exhibit vitamin D deficiencies (OR = 1.85; P = 0.0210). Conclusions: This is the first large epidemiologic study on the association between vitamin D and depression in a US representative sample survey. A significant positive association was found between subjects having an episode of depression and vitamin D deficiency. However, a causal relationship could not be established due to the cross-sectional nature of the study. Further studies need to investigate the mechanistic and causal relation between vitamin D and depression.
114

The role of retinol dehydrogenase 10 in vitamin A metabolism

Farjo, Krysten Michelle. January 2009 (has links) (PDF)
Thesis (Ph. D.)--University of Oklahoma. / Bibliography: leaves 150-172.
115

The effect of vitamin B-6 deficiency on the bioavailability of zinc in the rat.

Moodley, Dhanabaikum. January 1990 (has links)
No abstract available. / Thesis (M.Sc.)-University of Durban-Westville, 1990.
116

An overview of sodium, calcium, and vitamin D dietary-related behaviors of Chinese Canadians in Edmonton

Yu, Yan Han Unknown Date
No description available.
117

Vitamin A supplementation reduces reinfection with Ascaris in indigenous Panamanian preschool children

Payne, Leslie G. January 2005 (has links)
Vitamin A deficiency and intestinal parasitism coexist in developing countries. This study evaluated whether a national program of vitamin A supplementation (200,000IU retinyl palmitate every 6 months), if combined with deworming (400mg albendazole), slows reinfection with Ascaris . A baseline survey of 595 indigenous preschool children in the Bocas del Toro region of Panama showed high rates of stunting (61%) and nematode infection (Ascaris 79.5%, Trichuris 19%). All children were dewormed and 328 were included in the 5 month follow-up study. Of these, 106 children received vitamin A supplementation through the Ministry of Health (Vit A S+) and 222 children received no supplementation (Vit A S-). At 3 months post deworming, both the prevalence (P= 0.0004) and intensity (P= 0.0124) of Ascaris infection were higher in Vit A S- children than in Vit A S+ children, indicating that reinfection occurred more slowly in supplemented children. When the two supplement groups were further sub-divided by stature, Vit A S+ resulted in lower reinfection rates (P=0.0002) only in normal height children, and not in stunted children. Despite the tendency of public health policy to target malnourished children our study provides evidence of increased benefit of vitamin A supplementation in normal height children living in areas with chronic parasitosis.
118

Epidemiological and clinical studies of vitamin A in Black South African pre-school children.

Coutsoudis, Anna. January 1993 (has links)
The ocular complications of vitamin A deficiency have been known for many years, however, recent studies have suggested that marginal vitamin A status enlarges the risk of common childhood infections and increases mortality. It is therefore important to assess the vitamin A status, and some of its consequences, in children who are most likely to be at risk for vitamin A deficiency as this has important implications for promoting the health of children and for formulating appropriate primary health care policies. In South Africa very little data is available on vitamin A nutrition of communities; therefore one of the objectives of this research programme was to document the vitamin A status of African children who, because of historical inequities, are most likely to be at risk for deficiency. Sound, epidemiologically based surveys of vitamin A intake and body levels were conducted in a typical established township (using dietary intake as the measuring tool) and in a typical peri-urban informal settlement (using serum retinol and conjunctival impression cytology as the measuring tools). These studies revealed that the majority (97%) of children living in the established township surveyed had an adequate intake of vitamin A, whereas 44% of the children in the informal settlement had low serum retinol levels (20 ug/dL), and 18% had insufficient vitamin A, as assessed by 2 abnormal disc specimens, using the conjunctival impression cytology test. In order to investigate the interrelationsnips between vitamin A, other micronutrients and some risk factors, an analysis was undertaken of anthropometry, parasite infestation and blood concentrations of vitamin E, calcium, magnesium, phosphorous, albumin, haemaglobin, serum iron and ferritin and percent transferrin saturation. Significant positive correlations were found between serum retinol and all the biochemical indicators of iron metabolism studied except for serum ferritin. Ninety one percent of the children sampled were infested with parasites. These results highlight the fact that in this population close interconnections exist among nutrients and suggest that attempts at correcting vitamin A deficiency in such communities should be based on comprehensive intervention programmes rather than on single nutrient replacement. The impact of infections on blood levels of vitamin A was investigated in African children with severe measles. In addition, substances related to vitamin A metabolism such as other micronutrients (zinc, vitamin E) and proteins (retinol binding protein, prealbumin, albumin) were measured in serum. In addition the changes induced in these substances by vitamin A supplementation (offered in a randomised, double blind, placebo controlled trial) were studied. Serum retinol as well as the other nutrients measured were significantly reduced early in the exanthem in measles patients as compared to healthy controls. Vitamin A and prealbumin levels on day 8 (of the intervention trial) were significantly increased in the supplemented group compared to the placebo group. vitamin A levels in serum correlated with those of retinol binding protein (RBP), prealbumin and zinc. These findings strengthen the hypothesis that hyporetinaemia during measles is the consequence of impaired mobilisation of retinol stores from the liver. The effect of reversing the temporary lowering of serum retinol concentrations during acute measles infections by supplementation with vitamin A was investigated in a hospital based, randomized, double-blind, placebo controlled trial. The two groups were comparable in known covariates of measles severity : weight/age centiles; overcrowding; rash; total 90% of the patients had blood lymphocytes; serum levels pre-albumin, RBP, vitamins A and E. of zinc, albumin, hyporetinaemia. Integrated Morbidity Scores ( IMS) derived from diarrhoea, herpes and respiratory tract infection (radiologically confirmed) were assigned on day 8, at 6 weeks and 6 months - these were reduced by 82%, 61% and 85% respectively in the supplemented group. This was mainly due to reduced respiratory tract infection. There was one death in the placebo group. At 6 weeks there was significant weight gain in the supplemented group. Despite the selected sample, attention to multiple covariates enhances the validity of the data obtained and supports the current WHO recommendations for vitamin A supplementation during measles. There are several mechanisms by which vitamin A is thought to have its effect of reducing morbidity, one of which is by improving immune responsiveness. This particular mechanism has not been adequately studied in children; most of the studies having been conducted in animals. The effect of vitamin A supplementation on selected factors of immunity in African children with complicated measles was therefore investigated during the randomized double-blind, placebo controlled, intervention trial described above. Placebo and treated groups had similar baseline characteristics. In the treated group there was a significant increase in total number of lymphocytes (day 42, P = .05) and measles IgG antibody concentrations (day 8, p = .02), both of which have consistently been shown to correlate more closely with outcome in measles than other immunological, clinical and radiological factors. Interleukin-2 (IL-2) and plasma complement (C3 ) values were unaffected by vitamin A supplement.at.Lon , These findings reinforce results from animal studies which show that the pathways of vitamin A activity in decreasing morbidity and mortality are partly founded on selective immunopotentiation. In conclusion epidemiological and biochemical methods which were used to assess the vitamin A status of African children in South Africa revealed that overt vitamin A deficiency is not a Public health issue to the extent it is in the poor rice eating nations of the world. Marginal vitamin A deficiency is however prevalent in informal settlements. Interventions to reverse this marginal vitamin A deficiency should be incorporated in comprehensive programmes to ensure food security. Infections such as measles which increase utilisation and inhibit mobilisation from body stores are damaging to vitamin A homeostasis in the individual. The morbidity associated with measles can be reversed by high dose vitamin A supplementation during the acute phase of the infection. Improving immune responsiveness is one of the likely paths of vitamin A activity in decreasing morbidity from measles. / Thesis (Ph.D.)-University of Natal, Durban, 1993.
119

Association between Serum Vitamin D Concentrations and Depression in the US Population: National Health and Nutrition Examination Survey, 1988-1994

Milone, Cristiana 14 September 2009 (has links)
Background: The role of nutrients in mental health has recently been recognized and investigated. Vitamin D has been known to play a role in a wide range of diseases, such as bone, cardiovascular, and autoimmune diseases, and cancers. Recently, its role in cognitive function and mental health has been reported. Vitamin D receptor and hydroxylases have been mapped throughout the brain, suggesting a role for vitamin D in brain tissue. An inverse association between vitamin D and depression was observed in European epidemiologic studies. There is a paucity of data on the association between vitamin D concentrations and depression in the U.S. population. Objective: The objective of this study was to investigate the association between serum vitamin D concentrations and depression in a large, nationally representative sample survey, the third National Health and Nutrition Examination Survey 1988-1994 (NHANES III). Methods: The study sample included 7970 adults, ages 15-39 years, who completed the Diagnostic Interview Schedule for depression and had vitamin D concentrations measured. SAS and SUDAAN statistical software packages were used in data analysis. Multivariate logistic regression was used to estimate the likelihood of having depression in vitamin D deficient persons in relation to vitamin D sufficient persons, after taking several confounding variables into consideration. Significance was set at α < 0.05. Results: The prevalence of vitamin D deficiency was higher in women than in men (24 % vs. 15%), higher in African-Americans than in whites (60% vs. 10%), higher in people living in metropolitan rather than in rural areas (25% vs. 14%), and higher in subjects below the poverty threshold than in higher income subjects (29% vs. 14%). The prevalence of vitamin D deficiency increased as BMI increased. The diagnostic variables for depression did not show an association with vitamin D deficiency after adjusting for several confounding factors. However, subjects having a depressive episode at the time of the interview, were significantly more likely to exhibit vitamin D deficiencies (OR = 1.85; P = 0.0210). Conclusions: This is the first large epidemiologic study on the association between vitamin D and depression in a US representative sample survey. A significant positive association was found between subjects having an episode of depression and vitamin D deficiency. However, a causal relationship could not be established due to the cross-sectional nature of the study. Further studies need to investigate the mechanistic and causal relation between vitamin D and depression.
120

Breastfeeding practices, anemia and vitamin A deficiency of South African mothers and their young infants

Sibeko, Lindiwe N. January 2002 (has links)
The prevalence of sub-clinical vitamin A deficiency (VAD) and anemia of lactating women (n = 113) and their breastfed infants aged 1--6 months was measured among a peri-urbanite South African sample. Mother's mean hemoglobin (Hb) was 12.4 +/- 1.3 g/dL with 32% anemia (Hb < 12g/dL). Retinol in serum was 49.8 +/- 13.2 mug/dL and 66.0 mug/dL (median) in breast milk; no evidence of sub-clinical VAD. Infants, 62% &le; 3 months, had mean Hb of 10.9 +/- 1.1 g/dL (with anemia present (<11g/dL), in 50%). Mean infant serum retinol was 26.9 +/- 7.2 mug/dL (10% prevalence of marginal VAD). No infants were exclusively breastfed. Weaning foods and breast milk substitutes were introduced early and infant intake of traditional medicines was common (52%). Our data suggest that anemia was present in both mothers and infants while VAD was evident only in infants. This early occurrence of micronutrient deficiencies may be attributed to less than optimal breastfeeding practices.

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