A Study on Oral Vitamin D Megadoses

Study Overview
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Brief Summary
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The purpose of this study is to determine if infrequent administration of oral vitamin D megadoses is effective treatment to maintain serum 25-hydroxyvitamin D(3) above target levels of 50-75 nmol/L. The investigators hypothesize that 100 000 IU or at least 200 000 IU vitamin D3 in every three months would be effective and safe treatment to achieve the target levels.

Official Title
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A Randomized, Double-blind, Placebo-controlled Study on Oral Vitamin D Megadoses - 100 000 or 200 000 IU Vitamin D3 Every Three Months

Conditions
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Hypovitaminosis D

Intervention / Treatment
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* Dietary Supplement: vitamin D3 (cholecalciferol)
* Other: olive oil
* Dietary Supplement: calcium carbonate


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: female 70-80 yrs old Exclusion Criteria: disease or medication affecting calcium homeostasis renal failure (Pt-GFRe-CG < 35 ml/min)

Ages Eligible for Study
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Minimum Age: 70 Years

Sexes Eligible for Study
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Female

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: 200 000 IU vitamin D3 every three months<br> | Dietary Supplement: vitamin D3 (cholecalciferol)<br>* vitamin D3 (cholecalciferol) oil 20 000 IU/ml, oral dose of 200 000 IU or 100 000 IU (10ml or 5ml) every three months for one year.<br>* Other names: Vigantol vitamin D3 (cholecalciferol) oil 20 000 IU/ml;Dietary Supplement: calcium carbonate<br>* 1000 mg calcium per os every day for one year<br>|
| Experimental: 100 000 IU vitamin D3 every three months<br> | Dietary Supplement: vitamin D3 (cholecalciferol)<br>* vitamin D3 (cholecalciferol) oil 20 000 IU/ml, oral dose of 200 000 IU or 100 000 IU (10ml or 5ml) every three months for one year.<br>* Other names: Vigantol vitamin D3 (cholecalciferol) oil 20 000 IU/ml;Other: olive oil<br>* 10 ml (placebo group) or 5 ml (100 000 IU vitamin D3 group) oil per os every three months for one year<br>Dietary Supplement: calcium carbonate<br>* 1000 mg calcium per os every day for one year<br>|
| Placebo Comparator: placebo every three months<br> | Other: olive oil<br>* 10 ml (placebo group) or 5 ml (100 000 IU vitamin D3 group) oil per os every three months for one year<br>Dietary Supplement: calcium carbonate<br>* 1000 mg calcium per os every day for one year<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Serum 25(OH)D3 concentration in relation to the target levels of 50-75 nmol/L |  | 12 months (including 9 time points) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Decline of creatine clearance (Pt-GFRe-CG) >20% from baseline |  | 12 months (including 9 timepoints) | 
| Hypercalciuria (dU-Ca >10 mmol/24h) |  | 12 months (including 9 timepoints) | 
| Hypercalcemia (S-Ca-ion >1,3 mmol/l) |  | 12 months (including 9 timepoints) | 
| Serum PTH |  | 12 months (including 9 timepoints) | 
| Serum PINP |  | 12 months (including 5 timepoints) | 
| Serum CTX |  | 12 months (including 5 timepoints) | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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vitamin D supplementation, cholecalciferol, PTH, bone turnover markers, elderly women