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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.
1

The Relationship Between Vitamin D Status and Body Mass Index in a Racially Diverse Urban Population of Male and Female Pre- and Early Adolescents

Cork, Sarah M 02 June 2017 (has links)
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.
2

the Relationship between Vitamin D Statuses and Young Adult Women Asthma

Bian, Shiying 01 January 2011 (has links) (PDF)
Although maternal vitamin D status has been linked to asthma in offspring, the relationship between vitamin D status and asthma in adults still remains unclear. The current study assessed the relationship between measures of vitamin D status and self-reported asthma/wheeze in 186 healthy women aged 18-30 years. Although the risk of asthma/wheeze symptoms was three-times higher among women with low dietary vitamin D intake (<200 IU>/day) than in those with higher vitamin D intake, suboptimal serum levels of 25(OH)D ( <70 nmol>/L) were associated with a 48% lower risk of asthma/wheeze than “optimal” serum levels. These contradictory effects underscore the poor correlation between dietary vitamin D intake and serum vitamin levels and suggest that other components in vitamin D-rich foods may be protective. Alternatively, women with higher serum vitamin D levels may have spent more time outdoors, increasing their exposure to asthma triggers. This study also identified predictors of serum 25 (OH) D in this sample. In addition to total dietary vitamin D (r= 0.2; p=0.03), intake of cold cereal (p=0.02) also significantly predicted serum 25(OH)D levels. Among non-dietary factors, month of blood draw (p=0.05) and oral contraceptive use (p<0.0001) were positive predictors of serum 25(OH) D; sunscreen use (p=0.04) was a negative predictor. After adjusting for covariates, oral contraceptive use was associated with 25(OH)D levels that were on average 24 nmol/L greater than those observed in women who did not use oral contraceptives. Additional prospective studies are needed to further evaluate the relationship between vitamin D status and asthma.
3

Body composition, bone health and vitamin D status of African adults in the North West Province / Olusola Funmilayo Sotunde

Sotunde, Olusola Funmilayo January 2014 (has links)
Background In South Africa, as in many other developing countries, obesity has become a major health problem causing an increase in the incidence and prevalence of various non-communicable diseases. Research has shown that excess adiposity is associated with low vitamin D status and detrimental to bone health. Low vitamin D status has been linked to various non-communicable diseases which includes osteoporosis, and also the metabolic syndrome. Information is scarce on the role of lean mass and fat mass on bone health in the black South African population. There is also a shortage of data on the association between vitamin D status and the metabolic syndrome in the South African population. Aim The main aim of this study was to examine factors (vitamin D status, socio-economic status [SES] and lifestyle risk factors) associated with body composition, including bone health, as well as predictors of change in body composition in African adults in the North West Province of South Africa. Methods The first study that forms part of this thesis was a longitudinal study aimed at examining the effects of urbanization, socio-economic status and lifestyle factors on changes in body composition over 5 years in rural and urban black South African adults. A total of 1058 men and women above age 30 years from the Prospective Urban Rural Epidemiology study were included in this study. The second study to form part of this thesis aimed to examine the association between body composition and bone health in urban black South African women. Structured questionnaires were used to collect socio-demographic and lifestyle information including medication and tobacco use. This second study is cross-sectional in design and it included 189 postmenopausal women aged > 43 years old. Dual X-ray absorptiometry was used to assess bone mineral density, lean mass and fat mass, while structured and specific questionnaires were used to assess the habitual physical activity, food frequency and fracture risk. Habitual activity energy expenditure was also measured using an accelerometer with a combined heart rate monitor. The third study aimed to examine the association of serum 25 hydroxyvitamin D [25(OH)D] and parathyroid hormone (PTH) concentration, respectively, with the metabolic syndrome while controlling for adiposity in black women in the North West Province, South Africa. This third study is also cross-sectional in design and it included 209 HIV-negative urban women. Dual X-ray absorptiometry was used to assess adiposity, while habitual physical activity was accessed with questionnaire and habitual activity energy expenditure was also measured using an accelerometer with a combined heart rate monitor. Results Study 1: Over a 5-year period, body mass index (BMI) and waist circumference increased in both genders, but the change was significant for BMI (P<0.01) and waist circumference (P<0.001) in women only, indicating an increase in adiposity over time. Urban residency positively predicted changes in waist circumference in men (p < 0.05) and women (p < 0.001) as well as change in triceps skinfold thickness of men (p < 0.05). Being married positively predicted changes in BMI (p < 0.001) and waist circumference (p < 0.001) in men, while age negatively predicted changes in triceps skinfold thickness in women (p < 0.001). Study 2: Fat mass and lean mass were significantly positively associated with bone mineral density (BMD) and fracture risk when adjusted for potential confounders. However, lean mass and not fat mass remained significantly associated with femoral neck BMD (β = 0.49, p <0.001), spine BMD (β = 0.48, p< 0.0001) and hip BMD (β = 0.59, p< 0.0001). Lean mass was also negatively associated with fracture risk (β = -0.19 p =0.04) when both lean and fat mass were in the same model. Study 3: After adjusting for age, body fat, habitual physical activity, tobacco use and season, neither 25(OH)D nor PTH concentrations showed significant associations with having the metabolic syndrome. However, when body fat was replaced with waist circumference there was a weak positive association between 25(OH)D concentration and the metabolic syndrome. No significant association was found between PTH:25(OH)D ratio and the metabolic syndrome. Conclusion This thesis has highlighted that the prevalence of obesity among black South Africans is high particularly among women and urbanization played a significant role in the increasing adiposity of black South Africans in the North West province. Lean mass had a stronger association with bone health in comparison to fat mass in urban black South African women. Low 25(OH)D concentration was not associated with the metabolic syndrome while there was no significant association between PTH and the metabolic syndrome in our black South African women. / PhD (Dietetics), North-West University, Potchefstroom Campus, 2015
4

Body composition, bone health and vitamin D status of African adults in the North West Province / Olusola Funmilayo Sotunde

Sotunde, Olusola Funmilayo January 2014 (has links)
Background In South Africa, as in many other developing countries, obesity has become a major health problem causing an increase in the incidence and prevalence of various non-communicable diseases. Research has shown that excess adiposity is associated with low vitamin D status and detrimental to bone health. Low vitamin D status has been linked to various non-communicable diseases which includes osteoporosis, and also the metabolic syndrome. Information is scarce on the role of lean mass and fat mass on bone health in the black South African population. There is also a shortage of data on the association between vitamin D status and the metabolic syndrome in the South African population. Aim The main aim of this study was to examine factors (vitamin D status, socio-economic status [SES] and lifestyle risk factors) associated with body composition, including bone health, as well as predictors of change in body composition in African adults in the North West Province of South Africa. Methods The first study that forms part of this thesis was a longitudinal study aimed at examining the effects of urbanization, socio-economic status and lifestyle factors on changes in body composition over 5 years in rural and urban black South African adults. A total of 1058 men and women above age 30 years from the Prospective Urban Rural Epidemiology study were included in this study. The second study to form part of this thesis aimed to examine the association between body composition and bone health in urban black South African women. Structured questionnaires were used to collect socio-demographic and lifestyle information including medication and tobacco use. This second study is cross-sectional in design and it included 189 postmenopausal women aged > 43 years old. Dual X-ray absorptiometry was used to assess bone mineral density, lean mass and fat mass, while structured and specific questionnaires were used to assess the habitual physical activity, food frequency and fracture risk. Habitual activity energy expenditure was also measured using an accelerometer with a combined heart rate monitor. The third study aimed to examine the association of serum 25 hydroxyvitamin D [25(OH)D] and parathyroid hormone (PTH) concentration, respectively, with the metabolic syndrome while controlling for adiposity in black women in the North West Province, South Africa. This third study is also cross-sectional in design and it included 209 HIV-negative urban women. Dual X-ray absorptiometry was used to assess adiposity, while habitual physical activity was accessed with questionnaire and habitual activity energy expenditure was also measured using an accelerometer with a combined heart rate monitor. Results Study 1: Over a 5-year period, body mass index (BMI) and waist circumference increased in both genders, but the change was significant for BMI (P<0.01) and waist circumference (P<0.001) in women only, indicating an increase in adiposity over time. Urban residency positively predicted changes in waist circumference in men (p < 0.05) and women (p < 0.001) as well as change in triceps skinfold thickness of men (p < 0.05). Being married positively predicted changes in BMI (p < 0.001) and waist circumference (p < 0.001) in men, while age negatively predicted changes in triceps skinfold thickness in women (p < 0.001). Study 2: Fat mass and lean mass were significantly positively associated with bone mineral density (BMD) and fracture risk when adjusted for potential confounders. However, lean mass and not fat mass remained significantly associated with femoral neck BMD (β = 0.49, p <0.001), spine BMD (β = 0.48, p< 0.0001) and hip BMD (β = 0.59, p< 0.0001). Lean mass was also negatively associated with fracture risk (β = -0.19 p =0.04) when both lean and fat mass were in the same model. Study 3: After adjusting for age, body fat, habitual physical activity, tobacco use and season, neither 25(OH)D nor PTH concentrations showed significant associations with having the metabolic syndrome. However, when body fat was replaced with waist circumference there was a weak positive association between 25(OH)D concentration and the metabolic syndrome. No significant association was found between PTH:25(OH)D ratio and the metabolic syndrome. Conclusion This thesis has highlighted that the prevalence of obesity among black South Africans is high particularly among women and urbanization played a significant role in the increasing adiposity of black South Africans in the North West province. Lean mass had a stronger association with bone health in comparison to fat mass in urban black South African women. Low 25(OH)D concentration was not associated with the metabolic syndrome while there was no significant association between PTH and the metabolic syndrome in our black South African women. / PhD (Dietetics), North-West University, Potchefstroom Campus, 2015
5

Har D-vitamintillskott effekt vid behandling av Systemisk Lupus Erythematosus? : En litteraturstudie

Omoike, Gracious January 2019 (has links)
Introduktion: Systemisk Lupus Erythematosus är en prototypisk autoimmun sjukdom som gör att immunförsvarets antikroppar angriper kroppens egna vävnader, vilket leder till kronisk inflammation i kroppens organsystem. Idag finns ingen verksam behandling för Systemisk Lupus Erythematosus. Syftet med denna studie var att undersöka hur Dvitamintillskott påverkar Systemisk Lupus Erythematosus. Metod: Artiklarna hittades i databasen ”Pubmed” med sökningen ”Systemic Lupus Erythematosus and vitamin D supplementation”. Bland sökresultaten fanns sex relevanta artiklar som hade undersökt effekten av D-vitamintillskott på SLE. Resultat: Mer än hälften av patienterna i samtliga studier nådde serum 25(OH) D-nivåer som ansågs vara tillräckliga. D-vitamintillskottet minskade Th1/Th17-cellerna men ökade också Treg-celler och Th2-celler. Tre studier visade sig ha en signifikant minskning i sjukdomsaktivitet och anti-dsDNA antikroppar. Komplement C3 minskade i studie 2. Diskussion: Fem av studierna tyder på att oral administrering av D-vitamin tillskott har gett positiv inverkan på SLE. Två av de granskade studierna rapporterades inge positiv klinisk effekt hos deltagarna. Slutsats: D-vitamintillskott dämpar immunsystemet genom att öka Treg-celler och Th-2-celler men även minska Th1/Th17-celler och B-celler samt produktionen av autoantikroppar och anti-dsDNA-antikroppar. Effekten av D-vitamintillskott på komplement C3 och C4 är oklar. Det krävs dock fler studier med fler deltagarantal för att dra en slutsats om Dvitamintillskott kan användas som behandling för SLE. / Background: Systemic Lupus Erythematosus is a prototypical autoimmune disease in which antibodies attack healthy tissues in the body, causing inflammation in several organs. Aim: The aim of this literature study was to investigate the effect of Vitamin Dsupplementation on SLE. Method: The articles were searched in the database called ”Pubmed” using the search terms ”Systemic Lupus Erythematosus and Vitamin D supplementation”. Six of the articles which examined the effects of D-vitamin supplementation on SLE were relevant for this study. Result: More than half of the patients in all six studies reached sufficient serum 25(OH)D. Vitamin D-supplement reduced Th1/Th17-cells but increased Tregs-cells and Th2-cells. 3 studies showed a decrease in disease-activity and anti-dsDNA. C3 decreased in study 2. Discussion: Five studies indicated that the oral administration of vitamin-D supplementation had a positive effect on SLE. Two of the examined studies did not observe any clinical effect of the vitamin-D supplement. Conclusion: Vitamin-D supplement suppresses the immunesystem by increasing Treg cells and Th-2 cells but also reducing Th1/Th17-cells and B-cells as well as the production of autoantibodies and anti-dsDNA antibodies. The effect of vitamin D-supplement is unclear. More studies with more participants are required to determine if vitamin-D supplement can be used as a treatment for SLE.
6

Influência de polimorfismos em genes da rota da vitamina D em parâmetros antropométricos e bioquímicos

Grave, Nathália 17 December 2015 (has links)
Submitted by FERNANDA DA SILVA VON PORSTER (fdsvporster@univates.br) on 2016-08-31T19:30:52Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) 2015NathaliaGrave.pdf: 1012668 bytes, checksum: 34206baa81b06129beaa75c62787bbc4 (MD5) / Approved for entry into archive by Ana Paula Lisboa Monteiro (monteiro@univates.br) on 2016-09-05T19:29:54Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) 2015NathaliaGrave.pdf: 1012668 bytes, checksum: 34206baa81b06129beaa75c62787bbc4 (MD5) / Made available in DSpace on 2016-09-05T19:29:54Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) 2015NathaliaGrave.pdf: 1012668 bytes, checksum: 34206baa81b06129beaa75c62787bbc4 (MD5) Previous issue date: 2016-08 / Introdução: Muitos estudos tem relacionado a deficiência de vitamina D com o risco para as doenças crônicas, principalmente obesidade e dislipidemia. A vitamina D age através da ligação ao receptor de vitamina D (VDR), o qual forma heterodímeros com o receptor do retinoide X gama (RXRG). O gene GC codifica a proteína de ligação da vitamina D (DBP), a qual é responsável pelo transporte da vitamina D na corrente sanguínea. Considerando que a genética desempenha um papel importante na etiologia destas doenças, poucos estudos analisam a associação de variantes em genes da rota da vitamina D com parâmetros antropométricos e bioquímicos relacionados a estes desfechos. Objetivo: Investigar a associação entre polimorfismos de genes relacionados à rota da vitamina D, rs2228570 (gene VDR), rs2134095 (gene RXRG), rs7041 (gene GC), e parâmetros antropométricos e bioquímicos em uma amostra de adultos. Métodos: Medidas antropométricas e bioquímicas foram avaliadas em 542 indivíduos adultos de ambos os gêneros em uma amostra de base populacional. O DNA genômico foi extraído a partir de amostra de sangue e os polimorfismos foram genotipados pela reação em cadeia da polimerase (PCR) através de discriminação alélica TaqMan (Applied Biosystems, Foster City, CA). As comparações dos desfechos entre os genótipos foram feitas usando ANOVA, Kruskal-Wallis, qui-quadrado de Pearson ou teste exato de Fisher, e as interações gene-gene foram avaliadas usando modelo linear geral. Resultados: Não identificamos nenhum efeito principal dos polimorfismos nos parâmetros avaliados. No entanto, ao analisarmos as interações gene-gene, detectamos uma interação significativa entre os genes RXRG e GC sobre os níveis de colesterol LDL. Conclusões: Nossos achados evidenciaram uma interação significativa entre polimorfismos de dois genes da rota da vitamina D, rs2134095 (RXRG) e rs7041 (GC) sobre os níveis de colesterol LDL, corroborando os achados da literatura que tem consistentemente relacionado a vitamina D com o perfil lipídico. / Introduction: Many studies have related vitamin D deficiency with the risk for chronic diseases, especially obesity and dyslipidemia. Vitamin D acts by binding to the vitamin D receptor (VDR), which form heterodimers with the retinoid X receptor gamma (RXRG). The GC gene encoding the binding protein Vitamin D (BPD), which is responsible for the vitamin D transport in the bloodstream. Considering that genetics play a significant role in the etiology of these diseases, few studies have analyzed the association of variants in genes of vitamin D route anthropometric and biochemical parameters related to these outcomes. Objective: To investigate the association between gene polymorphisms related to vitamin D route, rs2228570 (VDR gene), rs2134095 (RXRG gene), rs7041 (GC gene), and anthropometric and biochemical parameters in a sample of adults. Methods: anthropometric and biochemical measures were assessed in 542 adults of both genders in a population-based sample. Genomic DNA was extracted from blood sample and polymorphisms were genotyped by polymerase chain reaction (PCR) using the TaqMan allelic discrimination (Applied Biosystems, Foster City, CA). Comparisons of outcomes between genotypes were performed using ANOVA, Kruskal-Wallis test, chi-square test or Fisher's exact test, and gene-gene interactions were assessed using general linear model. Results: We have not identified any major effect of polymorphisms in the evaluated parameters. However, when we analyze the gene-gene interactions, we detected a significant interaction between RXRG and GC genes on LDL cholesterol levels. Conclusions: Our findings showed a significant interaction between polymorphisms in two genes of vitamin D route, rs2134095 (RXRG) and rs7041 (GC) on the levels of LDL cholesterol, corroborating literature findings that have consistently related to vitamin D with the profile lipid.
7

Analys av 25-hydroxyvitamin D i primärvården

Börjesson, Emma January 2015 (has links)
Background: The interest of vitamin D has increased in the last years. That is because there is so many possible positive effects of vitamin D and also because many individuals has vitamin D deficiency. Modern man spends much time indoors which leads to lower levels of vitamin D. People who have emigrated from a sunny climate to a Nordic climate often gets a deficiency due to a more pigmented skin which requires a larger amount of UVB to get an adequate synthesis of vitamin D. Aim: The aim with this study is to compare and evaluate how similar the instrument mini VIDAS measures 25(OH)D total against the current existing method cobas e 602. A discussion about if 25(OH)D total has a place in primary health care is included in the study. Method: The comparison was based on 39 samples. The samples was analyzed on cobas e 602 and mini VIDAS. A precision test was performed. External controls from DEQAS was also included in the study. The results have been presented with simple linear regression analysis, mean value, SD and CV. Results: The comparison between cobas e 602 and mini VIDAS gave a coefficient of determination of 81,34 %. mini VIDAS was closest to the external controls target values. Conclusion: There is no obvious conclusions about if mini VIDAS fulfills the requirement to be introduced to primary health care. The coefficient of determination of 81,34 % should be at least 95 %. However is mini VIDAS closer to the external controls target values then cobas e 602. There is factors that implies that 25(OH)D total has a place in primary health care with regards to demand, use and because many individuals has vitamin D deficiency. The instrument is also user-friendly to a primary health care laboratory. / Bakgrund: Intresset för vitamin D har ökat de senare åren. Det beror dels på att det finns många eventuella positiva effekter av vitamin D och dels på att många individer har brist på vitamin D. Nutidens människa spenderar mycket tid inomhus vilket leder till lägre nivåer av vitamin D. Personer som har utvandrat från ett soligt klimat till nordiskt klimat får ofta brist på grund av en mer pigmenterad hud som behöver större mängd UVB för att få en adekvat syntes av vitamin D. Syfte: Syftet med den här studien är att jämföra och utvärdera hur lika det patientnära instrumentet mini VIDAS mäter 25(OH)D total mot befintlig metod cobas e 602. Diskussion om analysen 25(OH)D total har en plats i primärvården ingår även i studien. Metod: Jämförelsen baserades på 39 st prover. Proven analyserades på cobas e 602 och mini VIDAS. Ett precisionsförsök gjordes. Externkontroller från DEQAS inkluderades även i studien. Resultaten har presenterats genom enkel linjär regressionsanalys, medelvärde, SD och CV. Resultat: Jämförelsen mellan cobas e 602 och mini VIDAS gav en förklaringsgrad på 81,43 %. mini VIDAS var närmst externkontrollernas målvärden. Slutsats: Det går inte att dra självklara slutsatser ifall mini VIDAS uppfyller kraven att införas i primärvården. Förklaringsgraden som är på 81,43 % bör vara minst 95 %. Däremot överensstämmer mini VIDAS med externkontrollerna bättre än cobas e 602. Det finns faktorer som tyder på att analysen 25(OH)D har en plats i primärvården med avseende på efterfrågan, användningsområde och antal individer med brist. Instrumentet är dessutom användarvänligt för ett primärvårdslaboratorium.
8

Cord Blood Vitamin D Status and Neonatal Outcomes in a Birth Cohort in Quebec

Morgan, Catherine 05 November 2013 (has links)
Vitamin D status is assessed with circulating 25-hydroxyvitamin D [25(OH)D]. As some evidence suggests that low vitamin D status adversely affects neonatal health, this project aimed to determine the association between cord blood 25(OH)D levels and preterm birth (PTB; <37 weeks gestation), low birthweight (LBW; <2500 grams) and small for gestational age (SGA; <10th percentile) and to examine the relationship between maternal 25(OH)D levels during the first trimester of pregnancy and fetal 25(OH)D levels at birth in a Canadian population. This nested case-control study used serums, questionnaires and chart reviews collected in Quebec City. Compared to 25(OH)D concentrations ≥75 nmol/L, concentrations 37.5-<75, 50-<75, and <75 nmol/L were associated with lower odds of LBW, PTB and an adverse neonatal composite outcome, and PTB as well as LBW, respectively. Maternal and neonatal 25(OH)D were correlated (r=0.23, p<0.01; adjusted r=0.46, p<0.01). This study contributes to evidence for identifying further policy and research directions.
9

Investigating the links between muscle strength, sun exposure, dietary vitamin D intake and the vitamin D status of ambulatory older adults in South East Queensland

Borradale, David January 2008 (has links)
Vitamin D deficiency and insufficiency are now seen as a contemporary health problem in Australia with possible widespread health effects not limited to bone health1. Despite this, the Vitamin D status (measured as serum 25-hydroxyvitamin D (25(OH)D)) of ambulatory adults has been overlooked in this country. Serum 25(OH)D status is especially important among this group as studies have shown a link between Vitamin D and fall risk in older adults2. Limited data also exists on the contributions of sun exposure via ultraviolet radiation and dietary intake to serum 25(OH)D status in this population. The aims of this project were to assess the serum 25(OH)D status of a group of older ambulatory adults in South East Queensland, to assess the association between their serum 25(OH)D status and functional measures as possible indicators of fall risk, obtain data on the sources of Vitamin D in this population and assess whether this intake was related to serum 25(OH)D status and describe sun protection and exposure behaviors in this group and investigate whether a relationship existed between these and serum 25(OH)D status. The collection of this data assists in addressing key gaps identified in the literature with regard to this population group and their Vitamin D status in Australia. A representative convenience sample of participants (N=47) over 55 years of age was recruited for this cross-sectional, exploratory study which was undertaken in December 2007 in south-east Queensland (Brisbane and Sunshine coast). Participants were required to complete a sun exposure questionnaire in addition to a Calcium and Vitamin D food frequency questionnaire. Timed up and go and handgrip dynamometry tests were used to examine functional capacity. Serum 25(OH)D status and blood measures of Calcium, Phosphorus and Albumin were determined through blood tests. The Mean and Median serum 25-Hydroxyvitamin D (25(OH)D) for all participants in this study was 85.8nmol/L (Standard Deviation 29.7nmol/L) and 81.0nmol/L (Range 22-158nmol/L), respectively. Analysis at the bivariate level revealed a statistically significant relationship between serum 25(OH)D status and location, with participants living on the Sunshine Coast having a mean serum 25(OH)D status 21.3nmol/L higher than participants living in Brisbane (p=0.014). While at the descriptive level there was an apparent trend towards higher outdoor exposure and increasing levels of serum 25(OH)D, no statistically significant associations between the sun measures of outdoor exposure, sun protection behaviors and phenotypic characteristics and serum 25(OH)D status were observed. Intake of both Calcium and Vitamin D was low in this sample with sixty-eight (68%) of participants not meeting the Estimated Average Requirements (EAR) for Calcium (Median=771.0mg; Range=218.0-2616.0mg), while eighty-seven (87%) did not meet the Adequate Intake for Vitamin D (Median=4.46ug; Range=0.13-30.0ug). This raises the question of how realistic meeting the new Adequate Intakes for Vitamin D is, when there is such a low level of Vitamin D fortification in this country. However, participants meeting the Adequate Intake (AI) for Vitamin D were observed to have a significantly higher serum 25(OH)D status compared to those not meeting the AI for Vitamin D (p=0.036), showing that meeting the AI for Vitamin D may play a significant role in determining Vitamin D status in this population. By stratifying our data by categories of outdoor exposure time, a trend was observed between increased importance of Vitamin D dietary intake as a possible determinant of serum 25(OH)D status in participants with lower outdoor exposures. While a trend towards higher Timed Up and Go scores in participants with higher 25(OH) D status was seen, this was only significant for females (p=0.014). Handgrip strength showed statistically significant association with serum 25(OH)D status. The high serum 25(OH)D status in our sample almost certainly explains the limited relationship between functional measures and serum 25(OH)D. However, the observation of an association between slower Time Up and Go speeds, and lower serum 25(OH)D levels, even with a small sample size, is significant as slower Timed Up and Go speeds have been associated with increased fall risk in older adults3. Multivariable regression analysis revealed Location as the only significant determinant of serum 25(OH)D status at p=0.014, with trends (p=>0.1) for higher serum 25(OH)D being shown for participants that met the AI for Vitamin D and rated themselves as having a higher health status. The results of this exploratory study show that 93.6% of participants had adequate 25(OH)D status-possibly due to measurement being taken in the summer season and the convenience nature of the sample. However, many participants do not meet their dietary Calcium and Vitamin D requirements, which may indicate inadequate intake of these nutrients in older Australians and a higher risk of osteoporosis. The relationship between serum 25(OH)D and functional measures in this population also requires further study, especially in older adults displaying Vitamin D insufficiency or deficiency.
10

Effekten av vitamin D2 vs. D3 på 25(OH)D-statusen : En litteraturstudie / The effect of vitamin D2 vs. D3 on 25(OH)D status : A litterature study

Beyer, Sarah January 2018 (has links)
Bakgrund: Vitamin D finns i två olika former, det animaliska D3 (kolekalciferol) och det vegetabiliska D2 (ergokalciferol). Det har rått olika åsikter bland läkarkåren och allmänheten om vilken av de två formerna som är mest potent för att höja 25(OH)D-statusen i blodet, det värde som mäts för att avgöra vitamin D-halten i kroppen. Då vitamin D-brist är vanligt förekommande bland befolkningen i Norden är det viktigt att veta vilken form som har bäst effekt och som därför bör användas för att behandla och förebygga vitamin D-brist. Det har även betydelse för veganer som inte äter det animaliska D3, där rekommendationen kanske behöver ändras. Syfte: Syftet med studien var att ta reda på om det finns någon skillnad i potensen av D2 respektive D3 för att höja 25(OH)D-statusen i blodet och i så fall, att hitta möjliga orsaker till denna skillnad. Metod: Sex relevanta vetenskapliga originalartiklar, som har undersökt effekten av D2 vs. D3 på 25(OH)D-statusen i blodet, hittades i databasen PubMed. Studierna genomfördes mellan 2008 och 2017. Studiedeltagarna var vuxna friska människor. Resultat: Fyra av studierna pekade på att D3 var mer effektivt än D2 för att höja 25(OH)D-statusen. En studie kom fram till att det inte fanns någon skillnad i potensen mellan D2 och D3 och en studie visade att D2 var mer effektivt jämfört med D3 när det gällde daglig behandling med låga doser men att D3 uppvisade bättre effekt vid behandling med höga doser med två eller fyra veckors avstånd. Slutsats: Majoriteten av studierna visade en bättre effekt av D3 än D2 för att höja 25(OH)D-nivåer i blodet. De blandade resultaten samt det begränsade antalet studier och deltagare gör att det inte är möjligt att kunna komma fram till en tydlig slutsats. / Background: Vitamin D comes in two different forms, D3 from animals (cholecalciferol) and D2 from plants (ergocalciferol). There has been different opinions among physicians and the general public about which of the calciferols is more potent to raise 25(OH)D-levels in the blood, which is the value that is measured to determine the vitamin D-status in the body. Since vitamin D deficiency is common among the people of the Nordic countries it is important to know which form has the best effect and should be used to treat and prevent vitamin D deficiency. Furthermore, it is relevant for vegans who do not eat the animalic D3, where recommendations might have to be changed. Aim: The aim of the study was to find out if there were differences in potency of D2 vs. D3 to raise 25(OH)D status in the blood and if so, to find possible explanations for those differences. Methods: Six relevant original articles that examined the effect of D2 vs. D3 on 25(OH)D status in the blood, were found in the database PubMed. The studies where published between the years 2008 and 2017. The participants were healthy adults. Results: Four of the studies suggested that D3 is more effective than D2 in order to raise the 25(OH)D status. One study concluded that there is no difference in the effectiveness of D2 vs D3 and one study showed that D2 is more effective than D3 when it comes to daily treatment but that D3 has a better effect than D2 when treatment happens on a two or four weekly basis with large doses. Conclusion: Most of the articles suggested a better effectiveness of D3 than D2 to raise 25(OH)D levels in the blood. However, besides the mixed results, the number of studies and participants was too small to come to a clear conclusion.

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