Scatterplot of mean 25-OH-vitamin D serum concentrations during local wintertime from Neumayer Stations 2007–2012 vs. other studies at high latitudes.

<p>Scatterplot for comparison of mean values of 25-OH-vitamin D serum concentrations during local wintertime found at Neumayer Stations 2007–2012 and other previous studies of comparable latitudes, for studies where a range of latitudes were given the mean latitude was used for this depiction, a linear regression curve has been added (grey line), ^† denotes results from study [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0144130#pone.0144130.ref061" target="_blank">61</a>], ^‡ denotes results from study [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0144130#pone.0144130.ref062" target="_blank">62</a>].