The Cork Centre for Vitamin D and Nutrition Research together with the Office of Dietary Supplements at NIH who lead the Vitamin D Standardization Program (VDSP) and several collaborating European partners have applied protocols for standardizing 25(OH)D data in a number of important European population studies. Standardized 25(OH)D data allow for more meaningful comparisons within and across European countries and also for a better estimate of true prevalence estimates of vitamin D deficiency to be generated. These new important data are presented in summary in this new interactive map. Select the population/country you are interested in by pressing on the flag symbol. The flags representing different populations are colour coded based on prevalence of vitamin D deficiency (see key below). Copyright Cashman & Higgins 2016