Vitamin D Deficiency
Conditions
Keywords
adherence to medication, electronic monitoring
Brief 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.
Detailed description
Intervention study in patients with serum vitamin D \<50 nmol/l and polypharmacy, defined as ≥4 medicaments/day. Treatment duration: 6 months. Treatment groups are defined as Lm (liquid monthly 24'000 IU); Lw (liquid weekly 5'600 IU); Sm (solid monthly 20'000 IU) and Sw (solid weekly 5'600 IU). Cross-over design with identical form (liquid or solid) and switching frequence, i.e. from weekly to monthly treatment and vice versa, for 3 months each.
Interventions
DRUGVitamin D: liquid form, start weekly
Patient will start treatment with weekly schedule, and switch after 3 months to monthly schedule for another 3 months.
DRUGVitamin D: liquid form, start monthly
Patient will start treatment with monthly schedule, and switch after 3 months to weekly schedule for another 3 months.
DRUGVitamin D: solid form, start weekly
Patient will start treatment with weekly schedule, and switch after 3 months to monthly schedule for another 3 months.
DRUGVitamin D: solid form, start monthly
Patient will start treatment with monthly schedule, and switch after 3 months to weekly schedule for another 3 months.
Sponsors
University Hospital, Basel, Switzerland
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
Patient will be recruited by their general practitioners (GP) and allocated to the GP's form (liquid or solid). Patients will be randomly assigned to start weekly or monthly intake for 3 months, and switch to the other frequence for 3 more months.
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* vitamin D deficiency by serum level \<50 nmol/l * polypharmacy defined as 4 daily medicines or more * speaking German or Swiss German
Exclusion criteria
* hypercalcaemia * substitution treatment with cholecalciferol in the past 3 months * medication intake provided by a third person and not by the patient himself
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Adherence to medication | 3 months of treatment | Taking adherence: number of dosis taken divided by number of dosis prescribed. Timing adherence: number of dosis taken within a time interval (within 15% of the mean preset intake time) divided by number of dosis prescribed. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Serum level of vitamin D | 3 and 6 months | Level of serum vitamin D compared to baseline value. |
| Patients preferences | 3 months of treatment | Questionnaire with 5-point Likert scale (from 1=strongly disagree to 5=strongly agree) |
Countries
Switzerland
Outcome results
None listed