Correction to: European Journal of Clinical Nutrition https://doi.org/10.1038/ejcn.2014.209, published online 01 October 2014

In the ‘Design’ section of the original article, the following sentence “Participants’ blood was drawn for baseline values in November 2012, and then they were directly observed to take either 250,000 IU (6.25 g contained in five pills) of oral vitamin D3 (n = 14) or five pills of an identical placebo (n = 14)” was corrected to read “Participants’ blood was drawn for baseline values in November 2012, and then they were directly observed to take either 250.000 IU (6.25 mg contained in five pills) of oral vitamin D3 (n = 14) or five pills of an identical placebo (n = 14)”. The original article has been corrected.