None listed
Conditions
Brief summary
Observational studies, mostly from Europe and North America, suggest that people with low vitamin D status may have increased risks of some chronic diseases and death. Given that sunlight is essential for vitamin D synthesis this has prompted calls from some to relax sun protection messages or so increased population-wide vitamin D supplementation through expanded mandatory food fortification. However there is no strong evidence from clinical trials to support these measures and the International Agency for Research on Cancer has specifically called for randomised trials of high dose vitamin D supplementation for prevention of cancer and lowering of total mortality. We propose here to assess the feasibility of such a trial in the four eastern states of Australia. Participants randomly selected from the electoral roll will be invited to participate, and randomly assigned to a monthly intake of one of two vitamin D doses (60,000 IU/month or 30,000 IU/month) or placebo for 12 months. Baseline and post-intervention serum vitamin D levels will be measured. Outcomes will be recruitment rate, representativeness of the general population, change in vitamin D levels according to population subgroup and economics.
Interventions
Sponsors
Study design
Eligibility
Inclusion criteria
Residents in Queensland, New South Wales, Tasmania and Victoria aged between 60 and 85 years will be selected at random from the Commonwealth Electoral Roll. Half will be selected from capital cities and half from regional centres, selecting from postcodes that are within 20 kilometres of a pathology collection clinic. Selection will be stratified by state, region, age (in five-year age bands) and sex to ensure an equal state, region, age- and sex-distribution.
Exclusion criteria
People will be excluded if they are unable to give consent or to communicate well enough in English to understand study materials or if they indicate in an initial screening questionnaire that they: 1.Have any of the following medical conditions (which either preclude or require high dose vitamin D supplementation or prevent informed consent): hyperparathyroidism, sarcoidosis, nephrolithiasis, osteomalacia, osteoporosis, a history of renal calculi or colic 2. Are taking vitamin D at doses >600IU/day 3. Do not have a telephone (landline or mobile)