Dissertations / Theses on the topic 'Vitamin A deficiency in children. Vitamin A in the body. Children'

Background: Between 1961-1971 vitamin D deficiency was recognized as a public health issue in the UK, because of the lack of effective sunlight and the population mix [1, 2]. In recent years, health care professionals have cited evidence suggesting a re-emergence of the vitamin D deficiency linked to a number of health consequences as a concern [3-6]. Evidence from observational studies has linked low vitamin D status with impairment in glucose homeostasis and immune dysfunction [7-9]. However, interventional studies, particularly those focused on paediatric populations, have been limited and inconsistent. There is a need for detailed studies, to clarify the therapeutic benefits of vitamin D in these important clinical areas. Objective: The aims of this PhD thesis were two-fold. Firstly, to perform preliminary work assessing the association between vitamin D deficiency and bone status, glucose homeostasis and immune function, and to explore any changes in these parameters following short term vitamin D3 replacement therapy. Secondly, to assess the effectiveness of an electronic surveillance system (ScotPSU) as a tool to determine the current incidence of hospital-based presentation of childhood vitamin D deficiency in Scotland. Methods: Active surveillance was performed for a period of two years as a part of an electronic web-based surveillance programme performed by the Scottish Paediatric Surveillance Unit (ScotPSU). The validity of the system was assessed by identifying cases with profound vitamin D deficiency (in Glasgow and Edinburgh) from the regional laboratory. All clinical details were checked against those identified using the surveillance system. Thirty-seven children aged 3 months to 10 years, who had been diagnosed with vitamin D deficiency, were recruited for the bone, glucose and immunity studies over a period of 24 months. Twenty-five samples were analysed for the glucose and bone studies; of these, 18 samples were further analysed for immune study. Treatment consisted of six weeks taking 5000 IU units cholecalciferol orally once a day. At baseline and after completion of treatment, 25 hydroxyvitamin D (25(OH)D), parathyroid hormone (PTH), alkaline phosphatase (ALP), collagen type 1 cross-linked C-telopeptide (CTX), osteocalcin (OCN), calcium, phosphate, insulin, glucose, homeostasis model assessment index, estimated insulin resistance (HOMA IR), glycated hemoglobin (HbA1c), sex hormone binding globulin (SHBG), lipids profiles, T helper 1 (Th1) cytokines (interleukin-2 ( IL-2), tumor necrosis factors-alpha (TNF-α), interferon-gamma (INF-γ)), T helper 2 (Th2) cytokines (interleukin-4 (IL-4), interleukin-5 (IL-5), interleukin-6 (IL-6)), T helper 17 (Th17) cytokine (interleukin-17 (IL-17)), Regulatory T (Treg) cytokine (interleukin-10 (IL-10)) and chemokines/cytokines, linked with Th1/Th2 subset balance and/or differentiation (interleukin-8 (IL-8), interleukin-12 (IL-12), eosinophil chemotactic protein ( EOTAXIN), macrophage inflammatory proteins-1beta (MIP-1β), interferon-gamma-induced protein-10 (IP-10), regulated on activation, normal T cell expressed and secreted (RANTES), monocyte chemoattractant protein-1(MCP-1)) were measured. Leukoocyte subset analysis was performed for T cells, B cells and T regulatory cells and a luminex assay was used to measure the cytokiens. Results: Between September 2009 and August 2011, 163 cases of vitamin D deficiency were brought to the attention of the ScotPSU, and the majority of cases (n = 82) were reported in Glasgow. The cross-validation checking in Glasgow and Edinburgh over a one-year period revealed only 3 (11%) cases of clearly symptomatic vitamin D deficiency, which had been missed by the ScotPSU survey in Glasgow. While 16 (67%) symptomatic cases had failed to be reported through the ScotPSU survey in Edinburgh. For the 23 children who are included in bone and glucose studies, 22 (96%) children had basal serum 25(OH)D in the deficiency range (< 50 nmol/l) and one (4%) child had serum 25(OH)D in the insufficiency range (51-75 nmol/l). Following vitamin D3 treatment, 2 (9%) children had final serum 25(OH)D lower than 50 nmol/l, 6 (26%) children had final serum 25(OH)D between >50-75 nmol/l, 12 (52%) children reached a final serum 25(OH)D >75-150 nmol/l and finally 3 (13%) exceeded the normal reference range with a final 25(OH)D >150 nmol/l. Markers for remodelling ALP and PTH had significantly decreased (p = 0.001 and <0.0001 for ALP and PTH respectively). In 17 patients for whom insulin and HOMA IR data were available and enrolled in glucose study, significant improvements in insulin resistance (p = 0.04) with a trend toward a reduction in serum insulin (p = 0.05) was observed. Of those 14 children who had their cytokines profile data analysed and enrolled in the immunity study, insulin and HOMA IR data were missed in one child. A significant increase in the main Th2 secreted cytokine IL-4 (p = 0.001) and a tendency for significant increases in other Th2 secreted cytokines IL-5 (p = 0.05) and IL-6 (p = 0.05) was observed following vitamin D3 supplementation. Conclusion: An electronic surveillance system can provide data for studying the epidemiology of vitamin D deficiency. However, it may underestimate the number of positive cases. Improving vitamin D status in vitamin D deficient otherwise healthy children significantly improved their vitamin D deficient status, and was associated with an improvement in bone profile, improvements in insulin resistance and an alteration in main Th2 secreting cytokines.

Papua New Guinea has been classified by the World Health Organisation as an area where clinical vitamin A deficiency (VAD) exists. This is at variance with the experience of the local physicians who do not encounter classical VAD in clinical practice. This pilot study was carried out to resolve this contradiction, since many suggestions have been made to fortify foods with Vitamin A. If done in the absence of concrete data to back up this classification, it could take the focus away from the real problem as well as potentially create problems of Vitamin A toxicity. Therefore, answers from this study could have far reaching implications in a country such as PNG, which has high childhood mortality and limited financial and manpower resources. The objective of this study was to determine the vitamin A status and identify risk factors of VAD in children aged 6 months to 6 years in a rural area of Papua New Guinea. The survey was carried out in the Ramu region of Madang province. Households and children were randomly selected and standard questionnaires were used to collect information about diet, previous illnesses and night blindness. The weight and height of all children was recorded and an ocular and physical examination carried out by trained personnel. In addition, haemoglobin estimation and examination of blood films for malaria parasites was carried out in all the children. In a randomly selected number of children, estimations of serum retinol and other micronutrient levels were carried out. Results: A total of 609 children were enrolled in the study. Biochemical parameters were studied in 106 of them .The mean age of the children was 35 months. Possible night blindness was reported in 4 children. No xerophthalmia was seen. The prevalence of serum retinol levels ( 0.7 (mol/L (WHO suggested cut off values for subclinical VAD) was 10.3%. Anthropometric indicators indicated a high proportion of the children had stunting and wasting or both. Analysis of dietary patterns, maternal literacy, food availability and other surrogate indicators indicated that the population is at mild-moderate risk of developing VAD. In conclusion, no evidence of clinical vitamin A deficiency was found. Subclinical vitamin A deficiency seemed to occur in this population at a level of mild-moderate public health importance. Further studies need to be carried out to assess the situation in different areas in PNG before policy decisions can be made with regards to mass vitamin A supplementation.

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.

Background: With usual supplementation practices, most children are Vitamin D Deficient (VDD) following Congenital Heart Disease (CHD) surgery and alternative regimens need consideration. Methods/Results: i) A systematic review identified 88 pediatric trials of high dose vitamin D. Studies evaluating the Institute of Medicine (IOM) Tolerable Upper Intake Level (UL) did not rapidly normalize levels, while loading therapy (≥ 40000 IU) did so within 3 days. Hypercalcemia occurred more often with doses above 400000 IU. ii) A double blind RCT was designed to determine whether pre-operative administration of the IOM UL can prevent post-operative VDD. Results after the first 30 participants completed study procedures demonstrated it was possible to recruit (1.8 patients per month) and complete study procedures (i.e. blood collection). Unfortunately few participants (45%) received more than 30 doses of study drug. Conclusion: Prevention of post-operative VDD in the majority of CHD patients will require alternatives to the IOM recommendations.

Objective: To identify the magnitude of anaemia and deficiencies of Fe (ID) and vitamin A (VAD) and their associated factors among rural women and children. Design: Cross-sectional, comprising a household, health and nutrition survey and determination of Hb, biochemical (serum concentrations of ferritin, retinol, C-reactive protein and alpha(1)-acid glycoprotein) and anthropometric parameters. Multivariate logistic regression examined associations of various factors with anaemia and micronutrient deficiencies. Setting: Kalale district, northern Benin. Subjects: Mother-child pairs (n 767): non-pregnant women of reproductive age (15-49 years) and children 6-59 months old. Results: In women, the overall prevalence of anaemia, ID, Fe-deficiency anaemia (IDA) and VAD was 47.7, 18.3, 11.3 and 17.7%, respectively. A similar pattern for anaemia (82.4 %), ID (23.6%) and IDA (21.2%) was observed among children, while VAD was greater at 33. 6%. Greater risk of anaemia, ID and VAD was found for low maternal education, maternal farming activity, maternal health status, low food diversity, lack of fruits and vegetables consumption, low protein foods consumption, high infection, anthropometric deficits, large family size, poor sanitary conditions and low socio-economic status. Strong differences were also observed by ethnicity, women's group participation and source of information. Finally, age had a significant effect in children, with those aged 6-23 months having the highest risk for anaemia and those aged 12-23 months at risk for ID and IDA. Conclusions: Anaemia, ID and VAD were high among rural women and their children in northern Benin, although ID accounted for a small proportion of anaemia. Multicentre studies in various parts of the country are needed to substantiate the present results, so that appropriate and beneficial strategies for micronutrient supplementation and interventions to improve food diversity and quality can be planned.

The Maasai of East Africa traditionally consume a diet of milk, meat, and blood. Previous studies have found the Maasai to suffer from vitamin A deficiency (VAD). This micronutrient deficiency compromises systemic immunity and increases morbidity and mortality. A semi-quantitative food frequency questionnaire (FFQ) was used to investigate the vitamin A intake of small Maasai children in Loita, Kenya. On average, children consumed 596mug/dayRAE from retinoid sources and 956mug/dayRAE when coupled with beta-carotene sources. The measles virus (MV) has yet to be eradicated from East Africa and remains a threat to young children. The Maasai have developed methods to deal with this disease and improve systemic immunity by introducing medicinal plants into the diet. Plant species added to the milk and soups of small children were determined using the FFQ. Antiviral properties of the seven most common dietary plants were then investigated, measuring MV neutralization and MV production, and compared to 7 arbitrarily selected non-medicinal plants. Significant differences (X2 p < 0.05) were found between the antiviral actions of medicinal and non-medicinal species.

The overall aim of the research described in this thesis was to evaluate the effect of vitamin A supplementation on respiratory health, assessed by lung function in children aged 6--9 years. It comprises three studies.
The first study determined the magnitude of vitamin A deficiency in the target population in Wukro wereda, Northern Ethiopia. Of the 1339 eligible children identified by house to house surveys, 824 had complete data for vitamin A indicators and anthropometry. Xerophthalmia was detected in 5.8% of the children, 8.4% had serum retinol levels <0.35 mumol/L and 51.1% between 0.35--0.70 mumol/L. Liver vitamin A reserve was also found to be low in 41.0% of the children using the Modified Relative Dose Response (MRDR) and in about 85% of the children, the daily vitamin A intake was below the FAO/WHO basal requirement (<250 RE/day).
The second study found that in comparison with children with adequate vitamin A reserve (MRDR < 0.06), those with low reserve (MRDR ≥ 0.06) had forced expiratory volume in one second (FEV1) 48.8 ml (p = 0.006) lower when unadjusted, 23.1 ml (p = 0.04) when partially adjusted for age, gender and height and 14.1 ml (p = 0.20) when fully adjusted for demographic, general health, lung function and household related characteristics.
The third study describes the results of a randomized controlled trial (RCT) to evaluate the impact of vitamin A supplementation on respiratory health as assessed by change in FEV1 at 4 months. The average change was 53.3 ml (n = 496) and 53.8 ml (n = 501) in the vitamin A and placebo groups respectively. After adjusting for baseline covariates, the difference between them was -3.6 ml (95%CI: -21.6, 14.4). In sub-analysis of the data, gender and vitamin A status subcategories were found to be effect modifiers.
In conclusion, high dose vitamin A supplementation did not show an effect on change in FEV1 at 4 months in children aged 6--9 years with high prevalence of vitamin A deficiency. Sub-analysis findings suggest that the benefits to vitamin A intervention in the study setting can probably be achieved if the other nutritional deficiencies such as zinc are addressed. Moreover, the results also suggest that the effects of vitamin A supplementation on respiratory health status are complex and these need to be taken into account in future studies to assess the clinical and public health implications of vitamin A supplementation in this age group.

Introduction: Bone health development and maintenance is important in children to reduce the risk for osteoporosis later in life. Knowledge on the vitamin D and bone health status of preadolescent children in South Africa is limited. Vitamin D and body composition both play important roles in bone health, but the relationship between adiposity and bone mass in children has been debated. The objective of this study was firstly, to describe the bone health status, body composition and vitamin D status of preadolescent children in Pretoria, South Africa. Secondly, the study examined bone health in relation to body composition and vitamin D status. Methods: A cross-sectional study, using conveniently sampled preadolescent black children aged 5-10, was conducted. Body weight was measured with the Seca medical body composition analyser and height using the Seca 274 stadiometer. Dual x-ray absorptiometry (DXA) was used for bone health (bone mineral content (BMC), areal bone mineral density (BMD) and bone area at the total body less the head (TBLH) and lumbar spine (LS) sites) and body composition (body fat percentage, fat mass and lean mass) assessments (n = 84). Vitamin D status (25(OH)D2 and 25(OH)D3) was determined from blood spot analysis (n = 59). To compare bone health means between vitamin D status groups, children were grouped as sufficient (25(OH)D ? 30 ng/ml), insufficient (25(OH)D = 21-29 ng/ml) or deficient (25(OH)D ? 20 ng/ml) accordingly. To compare bone health means between body composition groups, children were grouped as normal (BMIfor- age Z-score ? 1) or over-nourished (BMI-for-age Z-score > 1). Simple linear regression models were used in defining the relationship between bone health parameters and body composition components. Adjustments of bone health parameters for height-for-age, gender, age and body composition components was done using multiple linear regression. Comparison between adjusted bone health parameters of normal and over-nourished were made using the student’s two sample t-test. Results: The 59 children in the vitamin D study groups had a 24% prevalence of low BMD for chronological age and 7% presented with a low BMC for chronological age. A peculiar finding was that LS-BMAD differed significantly between the vitamin D insufficient and deficient groups. There was no relationship between any bone health parameters at all sites measured and serum levels of 25(OH)D (p > 0.05). Fat mass (FM) and body fat percentage least explained the observed variation in bone health parameters, whereas lean mass (LM) was the most important body composition component in explaining the variations observed in bone health parameters. The relationship between LS bone health parameters and body composition components was weaker than the relationship between TBLH bone health parameters and body composition components. Summary and / or Conclusion: In this population, 66% of preadolescents were vitamin D insufficient or deficient, but with a healthy bone health status and 40% of the preadolescents were over-nourished with greater crude BMD than those with healthy BMI Z-scores. Vitamin D status does not appear to be associated with parameters of bone health. Lean mass was the greatest body compositional determinant for variations observed in bone health parameters. Bone health parameters of healthy and over-nourished children did not differ after adjusting for body composition.
Dissertation (MSc)--University of Pretoria, 2017.
Food Science
MSc
Unrestricted

Vitamin D deficiency is one of the most commented health issues at the moment, given the number of discoveries about its function in various tissues and organs. The principal action of vitamin D is related to calcium absorption and its implication in bone homeostasis, but, besides this, it has been implicated in several other diseases. Despite this huge interest in vitamin D, there are still few studies talking about vitamin D deficiency in children in our country, and especially in our region. Knowing the prevalence of vitamin D deficiency in specific place or region, it will be possible plan actions focusing prevention, early diagnosis and treatment, and thus to reduce complications and costs to public health. This study aims to determine the prevalence of vitamin D deficiency and the factors associated in healthy children of the outpatient pediatrics clinic of a university hospital in the central region of Rio Grande do Sul. This analytical cross-sectional study included 138 healthy children of the pediatrics clinic of the University Hospital of Santa Maria. The serum 25 (OH) D was performed by the Clinical Laboratory of the University Hospital. The associated factors were obtained through a questionnaire conducted by telephone. The results showed that the overall prevalence of vitamin D deficiency in the population studied was 42.7%, 12.3% with deficiency and 30.4% with insufficiency in vitamin D. The highest percentage of children with adequate levels occurred among infants, followed by preschoolers, schoolers and adolescents. The majority, 65.9%, received vitamin D supplementation on average by 21.6 (± 15.6) months. The principal risk factors identified were: the age group (preschoolers, schoolers and adolescents); residence in urban areas; no supplemental of vitamin D and lack of sun exposure. We conclude that the prevalence of vitamin D deficiency is high in the region studied, especially among adolescents. Besides age, no vitamin D supplementation and inadequate sunlight exposure are risk factors that increase the chance of insufficiency/deficiency in vitamin D.
A deficiência de vitamina D é um dos assuntos mais comentados da área da saúde na atualidade, face às várias descobertas sobre a sua função em diversos tecidos e órgãos. A ação mais conhecida da vitamina D é na absorção do cálcio e sua implicação na homeostase óssea, mas além disso, tem estudos comprovando a relação da vitamina D com diversas outras doenças. Apesar desse enorme interesse sobre a vitamina D, ainda existem poucos trabalhos na literatura falando sobre a deficiência de vitamina D em crianças em nosso país, e principalmente na nossa região. Conhecendo a prevalência da hipovitaminose D, em determinado local ou região, pode-se pensar em medidas de prevenção, diagnóstico precoce e tratamento, buscando assim reduzir as complicações e os custos para a saúde pública. Assim, o presente estudo tem por objetivo conhecer a prevalência de deficiência de vitamina D e os fatores associados à esta, em crianças saudáveis em seguimento em um ambulatório de pediatria de um hospital universitário, na região central do Estado do Rio Grande do Sul. Este estudo transversal analítico incluiu 138 crianças saudáveis em seguimento no ambulatório de pediatria do Hospital Universitário de Santa Maria. A dosagem sérica de 25(OH)D foi realizados pelo Laboratório de Análises Clínicas do HUSM, utilizando a coleta para exames de rotina já estabelecidos no ambulatório. Os fatores associados foram obtidos através de questionário realizado por telefone. Os resultados mostraram que a prevalência geral de hipovitaminose D na população estudada foi de 42,7%, sendo 12,3% das crianças deficientes e 30,4% insuficientes em vitamina D. O maior percentual de crianças com níveis adequados ocorreu entre os lactentes, seguido dos pré-escolares, escolares e adolescentes. A maioria, 65,9%, recebeu suplementação de vitamina D, em média, por 21,6 (±15,6) meses. Os fatores de risco identificados com maior significância foram: a faixa etária de pré-escolar/escolar/adolescente; residência em zona urbana; não suplementação de vitamina D e exposição solar. Conclui-se que a prevalência de hipovitaminose D é alta na região estudada, especialmente entre adolescentes. Além da faixa etária, a não suplementação de vitamina D e a exposição solar inadequada são fatores de risco, que aumentam a chance de insuficiência/deficiência em vitamina D.

Thesis (Ph. D.)--Ohio State University, 2004.
Title from first page of PDF file. Document formatted into pages; contains xiv, 133 p.; also includes graphics (some col.) Includes bibliographical references (p. 107-133). Available online via OhioLINK's ETD Center

Vitamin A deficiency (VAD) is a nutritional deficiency that can be caused by insufficient intake of food sources of vitamin A, or due to problems in their absorption, transport or use. This is a problem of great importance because of the deleterious consequences that require the body, such as compromising the immune system, increasing susceptibility to infections, damage caused in the process of growth and development, and affect vision and may cause from night blindness to irreversible blindness nutritional. Children under five years are one of the largest groups of biological vulnerability, particularly in post-weaning. It is therefore of fundamental importance to establish the prevalence of vitamin A deficiency in this group to enable appropriate information to the planning of measures to prevent and control this situation. The objective was to estimate the prevalence of vitamin A deficiency in children from 0 to 59 months of the semiarid region of Alagoas. For that, it was determined the serum retinol by high performance liquid chromatography resolution on a probability sample comprised 652 children. The prevalence of inadequate plasma retinol levels (<20μg/dL) was 44.8%. There was no significant difference in mean retinol by age. There was a statistically significant difference (p = 0009) in relation to gender, with higher rates of inadequacy among girls (55.4%). The World Health Organization states that a VAD prevalence of less than 20% characterized the situation as serious public health problem. Thus, this condition is more than set for the semiarid region of Alagoas, in that more than twice the cutoff point. Considering the existence of a national program established by the Ministry of Health directed the control of VAD, these results demonstrate the need for this to be properly assessed as to its operation and effectiveness.
Fundação de Amparo a Pesquisa do Estado de Alagoas
A deficiência de vitamina A (DVA) é uma carência nutricional que pode ser causada pela ingestão insuficiente de alimentos fontes de vitamina A, ou devido a problemas em sua absorção, transporte ou utilização. Trata-se de um problema de grande importância devido às conseqüências deletérias que impõe ao organismo humano, tais como o comprometendo do sistema imune, aumentando a susceptibilidade às infecções, os prejuizos causados no processo de crescimento e desenvolvimento, além de afetar a visão, podendo causar desde a cegueira noturna até a cegueira nutricional irreversível. As crianças menores de cinco anos constituem um dos grupos biológicos de maior vulnerabilidade, sobretudo no período pós-desmame. Assim, é de fundamental importância estabelecer a prevalência de hipovitaminose A nesse grupo de modo a possibilitar informações adequadas para o planejamento de medidas de prevenção e controle dessa carência. O objetivo deste trabalho foi estimar a prevalência de hipovitaminose A nas crianças de 0 a 59 meses da região semi-árida de Alagoas. Para isso, determinou-se o retinol sérico por cromatografia líquida de alta resolução em amostra probabilística formada por 652 crianças. , A prevalência de níveis inadequados de retinol (< 20μg/dL) foi de 44,8%. Não houve diferença significativa das médias de retinol por faixa etária. Foi observada uma diferença estatisticamente significante (p= 0,009) em relação ao gênero, com maior taxa de inadequação entre as meninas (55,4%). A Organização Mundial de Saúde estabelece que uma prevalência de DVA igual ou superior a 20% caracteriza a situação como grave problema de saúde pública. Assim, tal condição está mais do que estabelecida para a região semi-árida de Alagoas, na medida em que ultrapassou em mais de duas vezes o referido ponto de corte. Considerando a existência de um programa nacional instituído pelo Ministério da Saúde direcionado ao controle da DVA, tais resultados demonstram a necessidade de que o mesmo seja devidamente avaliado quanto à sua operacionalização e eficácia.

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.

Objectives: To assess the association between serum 25(OH)D and body mass index (BMI) in pre- and early-adolescents and to determine whether this association varies by demographic/clinical characteristics. Methods: Vitamin D status was determined using serum 25(OH)D in healthy pre- and early adolescents in Pittsburgh, PA (deficiency=/mL, insufficiency=12-/mL, sufficiency=≥20 ng/mL). Adiposity was quantified using BMI percentile (normal=<85th, overweight=>85th-95th, obese=>95th). The relationship between serum 25(OH)D and adiposity was assessed in the total population and after stratification by gender, race, Fitzpatrick skin type, age, and Tanner stage. Results: 294 children (mean age 10.2 + 2.1 years; 60% African American; median serum 25(OH)D=27.0 ng/mL) were studied. Serum 25(OH)D was significantly lower in obese (n=72) vs. overweight (n=48) and normal weight (n=171) participants at 23.6, 29.5, and 28.2 ng/mL, respectively; p=0.015. This trend remained significant for early adolescents but did not differ after stratification by other demographic/clinical characteristics. A significant negative correlation was found between BMI and serum 25(OH)D (r = -0.315; p=0.000). Regression analysis predicted that 25% of the variance in serum 25(OH)D levels was attributed to BMI, gender, race, skin type, age, pubertal status, daily vitamin D and calcium intake, sun exposure, and sunscreen use, with Tanner stage being the only significant independent predictor. Conclusions: A significant inverse association between serum 25(OH)D and adiposity was observed in a population of pre- and early adolescents. This relationship was stronger in early adolescents. A meta-analysis to further explore this association in pediatric populations is warranted.

Introduction: Micronutrient malnutrition has been identified as a serious health problem globally and is on the rise in South Africa. This is evident from the escalating burden of vitamin A deficiency (VAD) in South Africa. Rural infants are the most affected, as their diets often lack micronutrients. Food fortification, vitamin A supplementation and dietary diversity are the strategies that have been employed in South Africa to alleviate VAD. However, these strategies have not been effective, for various reasons. Biofortification is the production of micronutrient dense staple crops to alleviate micronutrient deficiencies. This strategy could complement existing strategies in the alleviation of VAD in South Africa and in other countries, especially in sub-Saharan Africa (SSA), where VAD is prevalent. Aim: The aim of this study was to investigate the nutritional composition and acceptance of a complementary food (soft porridge) made with provitamin A-biofortified maize by female infant caregivers from the rural areas of Umgungundlovu District of KwaZulu-Natal, South Africa. Objectives: (i) To evaluate the nutritional composition of soft porridge made with provitamin A-biofortified maize compared to non-biofortified white maize porridge; (ii) To assess the sensory acceptability of soft porridge made with the biofortified maize by black African female infant caregivers of varying age; and (iii) To determine the perceptions of the black African infant caregivers about the biofortified maize relative to the non-biofortified white maize. Methods: A cross-sectional study was conducted. Grains of two provitamin A-biofortified maize varieties and one white variety (control) were used. Grain and soft porridge of each variety of maize were analysed for their nutritional composition. The sensory acceptability of the porridges were evaluated by black African female infant caregivers, using a five-point facial hedonic scale. Focus group discussions were conducted, using some of the study subjects, to determine their perceptions about the provitamin A-biofortified maize. Results: The results showed that the grains of the provitamin A-biofortified maize varieties and their soft porridges were more nutritious than the control white variety in terms of energy, fibre, fat, protein, iron, zinc and phosphorus content. The results of the sensory evaluation indicated that there was no significant difference in the sensory acceptability of the biofortified soft porridges and the white maize soft porridge, irrespective of the age of the sensory evaluation panellists. The female caregivers perceived the biofortified maize as nutritious and health-beneficial and thought that infants would like its unique yellow colour and taste. However, the black African female caregivers perceived the provitamin A-biofortified maize as an animal feed or food for the poor. Nevertheless, the female caregivers expressed a willingness to give their infants porridge made with provitamin A-biofortified maize if it was cheap, readily available and health-beneficial. Conclusion: This study suggests that provitamin A-biofortified maize has the potential to be used as a complementary food item. Biofortification of maize with provitamin A could be used as a possible complementary strategy to assist in the alleviation of VAD in SSA. Furthermore, the relatively higher energy, fibre, fat, protein, iron, zinc and phosphorus content of the biofortified maize could contribute to the alleviation of protein-energy malnutrition and mineral deficiencies, respectively, which are prevalent in children of SSA. Although the findings of this study, like other previous studies, indicate that there are some negative perceptions about the provitamin A-biofortified maize, this study shows that provitamin A-biofortified maize soft porridge is as acceptable as white maize soft porridge to female infant caregivers from the rural areas of Umgungundlovu District of KwaZulu-Natal, South Africa. The female caregivers are thus likely to accept the biofortified maize for use as an infant complementary food in the form of soft porridge. Further research is recommended to expand the study area and consumer sample size in order to increase the confidence of inferring these results for large rural populations.
Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2014.