Studies from Perth 1, Hobart 2, central Victoria 3, and Adelaide 4 have recently drawn attention to the surprisingly high rates of vitamin D insufficiency and deficiency in Australia (often defined as≤ 50nmol/L and≤ 38nmol/L 25 hydroxyvitamin D3 respectively). There has been a lack of data from subtropical regions such as Queensland, where there is more intense ultraviolet radiation. Our group has an interest in vitamin D 5, and had the opportunity to examine vitamin D levels in a case-control study designed to examine risk factors for psychosis.

Within an area of south-east Queensland (latitude 27 0 south), we randomly sampled individuals with psychosis from a wide range of sites. A well control group was drawn from the same catchment area. Ultraviolet radiation levels were measured using a permanently mounted outdoor erythemal UV meter and sunshine duration was measured with a Campbell-Stokes recorder. Serum 25 hydroxyvitamin D3 levels were measured with a commercially available radioimmunoassay (DiaSorin Inc). All subjects gave written, informed consent, and the study was approved by the local Institutional Ethics Committee.