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Item Follow-up study of the dietary intake, anthropometric measurements, and blood pressure in children born to women in the Manawatu pregnancy study : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Nutritional Science at Massey University(Massey University, 2001) Al-Shami, EntesarWhen the proposal of the pilot study presented in this thesis was finally formulated, one of the first and important requirements was to obtain approval from accredited ethics committees. This proved to be a long and demanding process, but at the same time an interesting and useful experience. It was also somehow different from what was previously experienced in Kuwait, the researcher's home country. That was how the idea of presenting this thesis in two parts came into being. In the first part, the development of ethics codes and ethics committees was reviewed, a comparison of the process to obtain an ethical approval in New Zealand and in Kuwait was made, and the proposals presented to Massey University Human Ethics Committee (MUHEC) and to Manawatu-Whanganui Committee (MWEC) were outlined. Bioethics is a young discipline; the term "medical ethics" was first used at the beginning of the 19th century. However, codes of ethics of human research were only introduced towards the end of the first half of the 20th century. Hectic debates over these codes took place during the second half of the 20th century. On one side, there were growing concerns for the rights and safety of research participants, physically, psychologically and culturally, and on the other there were fears that scientific merits and benefits might be eroded by the limitations that research bioethics may enforce. These debates have resulted in amendments and changes in ethics codes, changes that probably will continue to develop during the 21st century. [From Introduction]Item Vitamin D and preschool children -- predictors of status and relationship with allergic and respiratory diseases in New Zealand : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Nutritional Science at Massey University, Albany, New Zealand(Massey University, 2015) Cairncross, Carolyn TinaBackground The role of vitamin D in allergic and respiratory conditions is increasingly being recognised through an immune-modulatory role. The current evidence is inconsistent, with very limited data in preschool children, a target group with high prevalence of early childhood allergic and respiratory disease. There are little data on the vitamin D status and factors associated with vitamin D deficiency in the preschool age group in New Zealand. Knowledge of these factors can assist prediction of preschool children at risk of vitamin D deficiency, improving health outcomes. Aims and Objectives To describe the vitamin D status of a self-selected sample of preschool children and determine predictors of vitamin D deficiency in order to develop a predictive questionnaire to assess vitamin D deficiency in this age group, and to investigate the relationship of vitamin D status and prevalence of allergic diseases - eczema, food allergy, allergic rhinoconjunctivitis and asthma – and respiratory infections. Method A cross-sectional sample of 1329 preschool children aged 2 to <5 years from throughout New Zealand enrolled during late-winter to early-spring in 2012. 25-hydroxyvitamin D (25[OH]D) was analysed from dried blood spots collected using capillary sampling. Caregivers completed a survey describing their child’s demographics, factors known to affect vitamin D status and medical history of allergic and respiratory diseases. Predictors of vitamin D deficiency (25[OH]D <25nmol/L) were identified using multivariable logistic regression in a randomly selected sub-sample (n=929) for development of a predictive questionnaire, which was then validated by receiver operating characteristics (ROC) analysis (n=400). Results Mean (SD) dried blood spot 25(OH)D concentration was 52 (19)nmol/L. Vitamin D deficiency was present in 86 (7%) and vitamin D insufficiency (25[H]D <50nmol/L) in 642 (48%)children. Factors independently associated with the risk of vitamin D deficiency were female gender (OR=1.92, 95%CI 1.17-3.14), children of other non-European ethnicities (not including Maori or Pacific) (3.51, 1.89-6.50), children whose mothers had less than secondary school qualifications (5.00, 2.44-10.21), who had olive-dark skin colour (4.52, 2.22-9.16), who did not take vitamin D supplements (2.56, 1.06-6.18) and who lived in more deprived households (1.27, 1.06-1.53). There were no children who drank toddler milk with 25(OH)D concentrations <25nmol/L thus these children had a zero risk of vitamin D deficiency. The predictive questionnaire had low sensitivity for the identification of children at risk of vitamin D deficiency (sensitivity 42%, specificity 97%). Children with 25(OH)D concentrations =75nmol/L had a two-fold increased risk for parent reported, doctor diagnosed food allergy (OR=2.21, 95%CI 1.33-3.68). No association was present between 25(OH)D concentration and prevalence of eczema, allergic rhinoconjunctivitis, asthma or respiratory infection. Conclusion Dried blood spot methods facilitated the measurement of 25(OH)D concentrations in a large sample of preschool children from throughout New Zealand. Prevalence of deficiency in winter was low (7%). The predictors of deficiency were consistent with those in previous studies of other age groups in New Zealand. The predictive questionnaire identified less than half of the children with vitamin D deficiency, so has limited diagnostic ability. In this sample of preschool children, vitamin D deficiency was not associated with allergic diseases or respiratory infections. In contrast, high vitamin D concentrations were associated with a two-fold increased risk of food allergy. This relationship between vitamin D status and allergic diseases is complex, and needs to be further investigated in the preschool age group.