Oral Vitamin D Substitution Weekly or Monthly and Adherence

University Hospital Basel

Status and phase: Completed; Phase 4

Conditions: Vitamin D Deficiency

Treatments: Drug: Vitamin D: liquid form, start monthly; Drug: Vitamin D: solid form, start weekly; Drug: Vitamin D: liquid form, start weekly; Drug: Vitamin D: solid form, start monthly

Study type: Interventional

Funder types: Other

Identifiers

NCT03141593

2017-00300

Details and patient eligibility

About

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.

Full 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.

Enrollment: 97 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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97 participants in 4 patient groups

Vitamin D: liquid form, start weekly

Active Comparator group

Description:

5'600 IU weekly (1.4 ml oily drops) start for 3 months, will cross-over to 24'000 IU monthly (5 ml alcoholic drops) for the following 3 months.

Treatment:

Drug: Vitamin D: liquid form, start weekly

Vitamin D: solid form, start weekly

Active Comparator group

Description:

5'600 IU weekly (1 soft capsule) start for 3 months, will cross-over to 20'000 IU monthly (1 tablet) for the following 3 months.

Treatment:

Drug: Vitamin D: solid form, start weekly

Vitamin D: liquid form, start monthly

Active Comparator group

Description:

24'000 IU monthly (5 ml alcoholic drops) start for 3 months, will cross-over to 5'600 IU weekly (1.4 ml oily drops) for the following 3 months.

Treatment:

Drug: Vitamin D: liquid form, start monthly

Vitamin D: solid form, start monthly

Active Comparator group

Description:

20'000 IU monthly (1 tablet) start for 3 months, will cross-over to 5'600 IU weekly (1 soft capsule) for the following 3 months.

Treatment:

Drug: Vitamin D: solid form, start monthly