Importance of Dosing Regimen for the Effect of Vitamin D Supplementation
Status:
Completed
Trial end date:
2018-05-01
Target enrollment:
Participant gender:
Summary
Vitamin D is a hormone with effects not only on the skeleton, but on most tissues in the
body. Lack of vitamin D is associated with cardio-vascular disease (CVD), type 2 diabetes,
cancer, infectious and immunological diseases, as well as risk factors for these diseases.
However, intervention studies with vitamin D have been inconclusive regarding diseases and
risk factors. This could be due to inclusion of subjects already vitamin D sufficient, and
short and underpowered studies. In addition, there are indications that the dosing regimens
may be important, so that daily doses with vitamin D are more efficient than intermittent
doses, which so far have been generally used. This could be related to the concentration of
circulating and thereby intracellular vitamin D concentrations, which probably is dependent
on daily vitamin D doses. This will be tested in the present study where 60 subjects will be
randomized to vitamin D 160 000 once, vitamin D 4000 IU/day, or placebo for four weeks. The
primary endpoints will be effects on serum hepcidin and plasma cathelicidin after 4 weeks,
with effects on serum PTH, RNA expression and microRNA in peripheral blood, telomerase
activity in peripheral blood mononuclear cells and the ration between serum 1,25(OH)2D and
24,25(OH)2D as secondary endpoints.