Pharmacokinetics Evaluation of Vitamin D Formulations

Participants are randomly divided into 4 groups. The first group receives regular Vitamin D3 (1000IU), the second receives microencapsulated D3 (1000IU), the third group receives regular Vitamin D3 (2500IU), the fourth receives microencapsulated D3 (2500 IU). Plasma concentrations of Vitamin D (D3, 25(OH)D3 and D2) are measured at baseline-before treatment start (day 0), during treatment (day 14) and at end of treatment (day 30). After the end of supplementation, blood vitamin D concentrations are checked again at day 45 and day 60.