Oral Vitamin D Substitution Weekly or Monthly and Adherence

Phase 4

Completed

• Conditions: Vitamin D Deficiency

• Registration Number: NCT03141593
• Lead Sponsor: University Hospital, Basel, Switzerland

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.

Study Timeline

• Study First Submitted: 2017-03-23
• Study First Submitted QC: 2017-05-02
• Study First Posted: 2017-05-05
• Study Start: 2017-10-09
• Primary Completion: 2018-10-31
• Study Completion: 2018-10-31
• Status Verified: 2020-02
• Last Update Submitted: 2020-02-10
• Last Update Posted: 2020-02-12

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 97

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

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Primary Outcome Measures

Name	Time	Method
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 Outcome Measures

Name	Time	Method
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)

Trial Locations

Locations (1)

Pharmaceutical Care Research Group; 🇨🇭 Basel, Switzerland