Research undertaken by the VitDAL was awarded a prestigious poster prize at the Annual Vitamin D workshop held in Boston. This conference is the largest annual gathering of researchers engaged in vitamin D research. Dr Mellanby presented the VitDAL initial research on the relationship between vitamin D status and reproductive outcomes in Soay sheep from St Kilda island which have been intensively studied by our collaborators at the Institute of Evolutionary Ecology at the University of Edinburgh, for over 30 years. This population of sheep is completely unmanaged and is geographical constrained so is an excellent study population in which to explore the relationship between vitamin D and a wide range of health outcomes. We discovered that vitamin D status, as assessed by serum 25(OH)D concentrations, was highly predictive of fecundity with sheep having twins have higher 25(OH)D concentrations than sheep with single or no lambs.