While is important to prevent vitamin D deficiency, controversies exist about optimal vitamin D intakes and concentrations. Our aim is to evaluate safety concerns with dosages of vitamin D which are routinely promoted for unsupervised public use with over the counter products. We will do this by evaluating long-term health effects for infant vitamin D supplementation, and by using a genetic approach to evaluate the causal effects of high vitamin D and calcium concentrations.
Physiological Function Of The Novel Vitamin D Receptor Isoform
Funder
National Health and Medical Research Council
Funding Amount
$465,750.00
Summary
Vitamin D regulates a wide range of physiological systems including those involved in control of calcium blood level and bone health as well as regulation of the immune system and of cell growth. Vitamin D action is mediated through the vitamin D receptor (VDR), a member of a large family of proteins that regulate the activity of specific target genes that control numerous biological functions. A novel, larger form of the human VDR has recently been described in our laboratory. This novel form s ....Vitamin D regulates a wide range of physiological systems including those involved in control of calcium blood level and bone health as well as regulation of the immune system and of cell growth. Vitamin D action is mediated through the vitamin D receptor (VDR), a member of a large family of proteins that regulate the activity of specific target genes that control numerous biological functions. A novel, larger form of the human VDR has recently been described in our laboratory. This novel form shows differences in activity from the shorter VDR form (VDRA) and also has an unusual distribution within the nucleus of the cell that may relate to its function. The present project focuses on further analysis of the relevance of this novel VDR isoform to normal physiology. We hypothesise that the larger VDR isoform has unique characteristics that may modify how vitamin D works in different cells and tissues, on specific target genes and in response to different active forms of vitamin D. These differences depend on this novel isoform s interaction with specific nuclear proteins that regulate the actions of other hormone receptors. The specific aims of this project are to study the functions of the novel VDR isoform in comparison to VDRA: * On different target genes that are either activated or inhibited in response to vitamin D, and on different cell lines from tissues where vitamin D has important roles, like intestine, kidney and bone * In their response to natural and synthetic vitamin D compounds, because of their possible therapeutic applications * In their interactions with intranuclear regulatory proteins, to understand the underlying mechanisms The study of these two forms of the VDR will help to clarify their potentially different cellular roles and their contribution to the wide range of physiological processes regulated by the vitamin D endocrine system. This understanding may open new paths for treatments of human bone and calcium-related diseases.Read moreRead less
Effects Of Vitamin D And Calcium On Bone Strength, Balance And Falls In Elderly Women
Funder
National Health and Medical Research Council
Funding Amount
$230,900.00
Summary
Many osteoporotic fractures occur as a result of bone fragility and falls. Both falls and fractures are huge public health problems in Australia. Falls are the leading cause of injury-related hospitalization and death in person older than 65 years of age. During 1996 almost 36,000 people attended a hospital after a fall and 5% of these resulted in fracturing a bone. The incidence of fall-related hospital admission increases exponentially with age, reaching 4% per annum for men and 7% per annum f ....Many osteoporotic fractures occur as a result of bone fragility and falls. Both falls and fractures are huge public health problems in Australia. Falls are the leading cause of injury-related hospitalization and death in person older than 65 years of age. During 1996 almost 36,000 people attended a hospital after a fall and 5% of these resulted in fracturing a bone. The incidence of fall-related hospital admission increases exponentially with age, reaching 4% per annum for men and 7% per annum for women aged 85 years and older. In the community approximately one third of older people fall each year. Compared to men, women are three times more likely to be hospitalized or one and half times more likely to die from a fall-related injury. Importantly women have an increased risk of fracture and over 40% of women over the age of 50 will break a bone. Previous European and American studies suggest that calcium replacement may improve bone strength while vitamin D may reduce falls. However, the separation of these two effects has never been studied. We have previously studied elderly falling women who attended the Emergency Department of large teaching hospitals in Perth and have shown that many are calcium and vitamin D deficient. We are undertaking a short term randomized controlled trial of calcium alone or calcium with vitamin D, to study the effects on bone strength as measured non-invasively, balance and falls in this high risk group of subjects. We have already recruited 100 subjects and six subjects have completed their 6 months assessment. We plan to recruit the remaining 200 subjects during the following 12 months and give all subjects one year of treatment. At the end of this study we should be able to offer clear treatment guidelines for this high risk group of patients.Read moreRead less
Quantitiative Assessment Of Solar UV Exposure For Vitamin D Synthesis In Australian Adults
Funder
National Health and Medical Research Council
Funding Amount
$1,162,536.00
Summary
This research program will add significantly to our current scientific understanding of the dual health outcomes of UV exposure (Vitamin D and skin cancer) . This project is in line with Australia's R and D Priorities, in that it will result in direct and indirect social and economic benefits to Australia by applying the scientific knowledge gained through this research to develop public health initiatives to improve some of Australia's most significant and costly health problems.
Autocrine Vitamin D Metabolism, Activity And Bone Health
Funder
National Health and Medical Research Council
Funding Amount
$459,270.00
Summary
This project will provide the detailed understanding of the activities of vitamin D within the bone microenvironment and offers the exciting prospect of elucidating the mechanistic reasons for maintaining an adequate vitamin D status in relation to the prevention of osteoporotic hip fractures. Thus, this project has great potential to improve community health by being able to recommend vitamin D supplementation made on the basis of maintaining normal bone cell function.
Vitamin D And Genetic Susceptibility In Multiple Sclerosis
Funder
National Health and Medical Research Council
Funding Amount
$122,714.00
Summary
Vitamin D3 levels appear to predict clinical status in multiple sclerosis. The reasons for this are unclear, but may be linked to the effect of the Vitamin D Receptor (VDR) on a subset of immune cells. This project aims to identify key genes which are regulated by this receptor, by using specific gene sequencing technologies combined with knowledge of the genes which confer risk of developing MS. This may help to identify the molecular pathways underlying MS and potential treatment strategies.
The Regulation Of Vitamin D-Dependent Bone Metabolism
Funder
National Health and Medical Research Council
Funding Amount
$612,535.00
Summary
This project aims to establish the cellular basis for the importance of vitamin D in bone. This information is necessary to develop public health nutritional recommendations for improving in skeletal health and reducing the incidence of hip factures in the elderly. Furthermore our data have the potential to reveal novel activities of vitamin D that could eventuate as pharmacological targets.
Improving Vitamin D Status And Health In Young Women
Funder
National Health and Medical Research Council
Funding Amount
$607,307.00
Summary
Vitamin D deficiency is a significant public health concern, affecting up to 50% of Australian women, potentially impacting on many chronic health conditions and increasing suffering, economic loss and premature death. This study will lead to the development of safe, effective interventions to address this important health issue. In particular we will assess the effectiveness of a lifestyle intervention to safely improving vitamin D status.