Clinical Research Directory

Inclusion Criteria: * British white European, black African/Caribbean, or South Asian (self-reported) * Living in England for \>2 months * Aged \>18 years * No significant health issues * English or Urdu speaker Exclusion Criteria: * Medical condition or history which might impact study measurements (e.g., ischaemic heart disease, type 1 and type 2 diabetes, thyroid disease, osteoporosis, haematological disease, malignancy) * Medications known to affect vitamin D metabolism (i.e., hormone replacement therapy, anti-oestrogens treatment, antiepileptic drugs, and breast cancer treatment) * Pregnant or planning pregnancy during the study period * Regular use of sun beds * Having a sun holiday one month prior to commencing study or plans for a sun holiday within the study period. A sun holiday is generally defined as a holiday in a sunny resort outside of the UK. The researchers will assess this on a case-by-case basis depending on the time of year and expected weather conditions * Reported participation in another clinical trial occurring simultaneously * Previous intolerance or allergic reaction to vitamin D