Fortifying food with a fat-soluble vitamin D₃ (cholekalcyferol) is usually carried out using some carriers that are fat derivatives. Based on the amino-acid sequence in β-lactoglobulin (β-LG) chain and on the results of research into its 3-dimensional structure, the β-lactoglobulin can be classified into a family of lipocalins. Consequently, it is possible to use β-lactoglobulin as a carrier of vitamin D₃ in food products with a reduced fat content. Under the scope of study, complex compounds of β-lactoglobulin with vitamin D₃ were developed and a preparation in the form of powder was produced. Spray drying and freeze drying processes were applied since those two methods are most frequently recommended in food industry to dry thermo-changeable substances. Next, using an HPLC analysis, the content of vitamin D₃ was determined in the complex compounds developed, and the assessment was performed of the effect of the technological process applied on the content of vitamin D₃ in the products. The research results confirmed the potential of producing complexes of β-lactoglobulin with cholecalciferol. The level of cholecalciferol in the spraydried samples was comparable to the level of D₃ in the freeze-dried sample. It was found that the material feed flux impacted the content of vitamin D₃ in the complex compounds developed, whereas the process temperature during spray-drying was found to have no impact on the content of vitamin D₃ therein.