Influence of Vitamin D Treatment on Multi-systemic Functions in Young Men With Vitamin D Deficiency Due to Work Conditions

Study Overview
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Brief Summary
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Vitamin D has multiple systemic effects: bone and calcium metabolism, muscle function, insulin responsiveness, body-composition regulation, cell differentiation, and the immune system. Proper status of vitamin D is found to be related to risk reduction in hypertension, cardiac and vascular diseases, autoimmune diseases, and others. Furthermore, vitamin D supplementation resulted in improved endothelial function. Limited sun exposure may lead to vitamin D deficiency, and it may be assumed that modern life styles lead to a lack of sun exposure. Long work-days may be the primary risk factor for vitamin D deficiency. The purpose of this research is to study the effect of vitamin D treatment on multi systemic functions in young healthy men with vitamin D deficiency due to working conditions.

Detailed Description
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The study has 2 stages: first stage would be survey of 400 employees, who will fill out a questionnaire to identify occupational and demographic risk factors, a nutritional questionnaire, and data from periodic checkups will be collected. Participants will sign a consent form for vitamin D level determinations, and for freezing blood samples. From this survey, the participants that have vitamin D deficiency (25(OH)D levels < 20 ng/ml) will continue to the second stage of the study - administration of vitamin D or placebo. Participants in the interventional study will sign an additional consent form. Length of follow-up: one year. All parameters will be tested at 0, 6, and 12 months.

Official Title
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Prospective, Randomized, Double Blind Placebo Controled Clinical Trial to Assess the Multi- Systemic Effect of Vitamin D Supplementation on Young Men With Vitamin D Deficiency

Conditions
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Vitamin D Deficiency

Intervention / Treatment
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* Dietary Supplement: Vitamin D
* Dietary Supplement: Placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy men between 20-65 years old For stage 2: baseline 25(OH)D levels < 20 ng/ml Exclusion Criteria: Liver dysfunction Kidney dysfunction Patients with unbalanced chronic diseases Regular use of medications that lower serum vitamin D levels, or which interfere with intestinal vitamin D absorption

Ages Eligible for Study
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Minimum Age: 25 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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Male

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: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: vitamin D<br> | Dietary Supplement: Vitamin D<br>* Oral vitamin D 100,000 IU<br>|
| Active Comparator: placebo<br> | Dietary Supplement: Placebo<br>* Placebo<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Serum level of 25(OH)D |  | 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood pressure, Endothelial function, Muscle strength. Quality of life, absence from work Laboratory measures:PTH, P1NP, β-CTx, Inflammation markers (hs-CRP), Fasting glucose levels, Insulin, Lipids profile |  | 12 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Quality of life