Oral Vitamin D Substitution Weekly or Monthly and Adherence
Status:
Completed
Trial end date:
2018-10-31
Target enrollment:
Participant gender:
Summary
Vitamin D deficiency (defined as 25(OH)-vitamin D serum level <50 nmol/l) is cured with
supplementation by mouth. National guidelines recommend the administration of 800 IU
cholecalciferol daily for an effective treatment, especially during the winter (poor sun
exposition). Commercially available pharmaceutical forms are liquid in Switzerland (drops)
and solid forms in Germany (tablets and capsules). Because therapeutic range of vitamin D3 is
wide and toxicity is seldom reached, even after the consumption of 200'000 IU, and because
the administration of 8 drops daily is inconvenient, weekly and monthly administrations of
the cumulative amount (i.e., 5'600 IU weekly or 24'000 IU monthly) have been investigated.
Both administration schedules are therapeutic equivalent. The study aims to investigate which
form (liquid or solid) and which schedule (weekly or monthly) procure the highest adherence
behavior with outpatients under polypharmacy i.e., with 4 or more medications daily. The
investigators will use commercially available Swiss and German products.