Skip to main content
OpenTrials
Completed

NCT Number: NCT03141593

Oral Vitamin D Substitution Weekly or Monthly and Adherence

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.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Vitamin D Deficiency Avitaminosis Deficiency Diseases Malnutrition Nutrition Disorders Nutritional and Metabolic Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 4

Primary location

Pharmaceutical Care Research Group

Basel, 4056, Switzerland

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Vitamin D: liquid form, start weekly

Drug

Patient will start treatment with weekly schedule, and switch after 3 months to monthly schedule for another 3 months.

Other names: Vitamin D3 Streuli

Vitamin D: liquid form, start monthly

Drug

Patient will start treatment with monthly schedule, and switch after 3 months to weekly schedule for another 3 months.

Other names: Vi-De 3 Monatsdosis

Vitamin D: solid form, start weekly

Drug

Patient will start treatment with weekly schedule, and switch after 3 months to monthly schedule for another 3 months.

Other names: Dekristolvit D3

Vitamin D: solid form, start monthly

Drug

Patient will start treatment with monthly schedule, and switch after 3 months to weekly schedule for another 3 months.

Other names: Dekristol

Primary outcomes

  1. Adherence to medication

    Time frame: 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 outcomes

  1. Serum level of vitamin D

    Time frame: 3 and 6 months

    Level of serum vitamin D compared to baseline value.

  2. Patients preferences

    Time frame: 3 months of treatment

    Questionnaire with 5-point Likert scale (from 1=strongly disagree to 5=strongly agree)

Sponsors and collaborators

Lead sponsor

University Hospital, Basel, Switzerland

Other

Registry information

Official study title

Oral Vitamin D Substitution Weekly or Monthly - Which Procedure Leads to Highest Adherence? A Prospective Intervention Study in Outpatient Care

Important dates

Study start
2017
Primary completion
2018
Study completion
2018
First posted
May 5, 2017
Registry last updated
Feb 12, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.