Effect of Vitamin D Supplementation on Muscle Mass and Function

Study Overview
=================
Brief Summary
-----------------
The study was designed to assess the effects of vitamin D supplementation during exercise training on body composition, muscle function, and glucose tolerance. The investigators hypothesis for these studies is that vitamin D supplementation enhances exercise-induced increases in strength and lean mass, potentially through enhancing insulin sensitivity and reducing inflammation.

Detailed Description
-----------------
The study was designed to assess the effects of vitamin D supplementation during exercise training on body composition, muscle function, and glucose tolerance. It was a double-blind, randomized, placebo-controlled, clinical trial with participants randomized into either a 4,000 IU/day vitamin D or placebo group and all participants completed 12 wks (3 d/wk) of exercise training.

Official Title
-----------------
Impact of Vitamin D Supplementation on Strength and Lean Mass Accumulation During an Exercise Intervention

Conditions
-----------------
Obesity, Insulin Resistance, Inflammation

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


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Physical activity scores in the low to very low category Fitness estimations in the below average or lower categories body mass index scores >24.9 indicating overweight or obesity. Exclusion Criteria: Use of tanning booths or other artificial UV light exposure High baseline vitamin D and calcium intake Plans to visit sunny/warm destinations during the winter months/study period History or presence of metabolic disease, type 2 diabetes, eating disorders, gastrointestinal disorders, pregnancy or lactation Use of drugs to treat obesity (last 12 weeks) Use of over the counter anti-obesity agents (last 12 weeks) Recent initiation of an exercise program (last four weeks).

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
-----------------
All

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Vitamin D<br>Participants in this arm consumed a 4000 IU vitamin D supplement daily for 12 weeks while participating in a resistance exercise training program. | Dietary Supplement: Vitamin D<br>* 4000 IU of vitamin D per day for 12 weeks.<br>* Other names: cholecalciferol;|
| Placebo Comparator: Placebo<br>Participants in this arm consumed a placebo (microcrystalline cellulose) daily for 12 weeks while participating in a resistance exercise training program. | Dietary Supplement: Vitamin D<br>* 4000 IU of vitamin D per day for 12 weeks.<br>* Other names: cholecalciferol;Drug: Placebo<br>* Placebo (microcrystalline cellulose) ingestion each day for 12 weeks.<br>* Other names: microcrystalline cellulose;|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Muscle Function | The primary endpoint is the change in lean mass (kilograms) after the three month resistance exercise intervention. | three months | 
| Glucose Tolerance | The primary endpoint is the change in the area under the glucose curve following an oral glucose tolerance test prior to and after the three month intervention. | three months | 
| Inflammation | The primary endpoint is the change in C reactive protein after the three month intervention | three months | 

 Terms related to the study
=================
Keywords Provided by Centre Hospitalier Valida
-----------------
25-hydroxyvitamin D, Parathyroid hormone, Lean mass, Muscular strength, Glucose tolerance