The invention relates to a dimeric complex of a selectively deglycosylated vitamin D-binding protein (GcMAF) and cholecalciferol (calciol). The invention further relates to a method for producing such a complex, wherein a vitamin D-binding protein is reacted with calciol and is selectively deglycosylated before or after being reacted. The resulting product is finally separated from impurities with a larger molecular weight, in particular enzymes of the selective deglycosylation process, using a molecular sieve with a cutoff value of more than 60 kDa.