Serum 25(OH)-Vitamin-D3 measurements.
25(OH)-Vitamin-D3 (=25(OH)VitD3) was measured in serum from baseline
visits at the Dept. of Paediatrics and Adolescent Medicine of the
Friedrich-Alexander Universität Erlangen-Nürnberg (Erlangen, Germany).
Thereby LC-MS/MS MassChrom Kit from Chromosystems was used according to
the manufacturers protocol.