Vitamin D and Muscle Metabolic Function

Study Overview
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Brief Summary
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The purpose of this study is to identify the magnitude of muscle lipid redistribution and muscle oxygen use in individuals 60 years old or older following combined treatment of vitamin D repletion and aerobic training compared to vitamin D repletion alone, aerobic training alone, or no treatment.

Detailed Description
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The investigators plan to recruit approximately 56 aged individuals with vitamin D insufficiency for a 13 week trial. All subjects will be 60 years of age or older. Participants will be randomized to one of four groups: vitamin D (50,000IU/wk) + aerobic training (7 days during the 13th week); vitamin D (50,000IU/wk) + normal daily activity during the 13th week; placebo + aerobic training (7 days during the 13th week); or placebo + normal daily activity during the 13th week. Following screening and informed consent process a physical activity questionnaire will be administered. A blood draw will then be conducted at baseline, midpoint and endpoint. Collected blood for the purposes of this study will assess vitamin D status (25(OH)D), parathyroid hormone, ionized calcium, insulin, and a comprehensive metabolic panel. At baseline and endpoint muscle lipid will be assessed using Magnetic Resonance Spectroscopy and muscle oxygen consumption will be determined using a novel hybrid diffuse optical instrument consisting of a near-infrared spectroscopy and a diffuse correlation spectroscopy. In addition, at each study time point 3 dietary recalls will be completed and physical activity will be measured using an accelerometer.

Official Title
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Vitamin D Contribution to Muscle Metabolic Function in Aged Adults

Conditions
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Healthy

Intervention / Treatment
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* Dietary Supplement: vitamin D
* Other: aerobic training


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age: 60 and older BMI: 18.5-29 Communicates fluently in English Exclusion Criteria: Metal implant not suitable for MRI Any form of hormone replacement therapy Engage in more than 1 hr/week of vigorous activity Participated in a high-intensity resistance or aerobic training program in the last 3 months Lower extremity injury or surgery in the past 3 months Foot sores or bone conditions severely limiting ability to move or perform exercise or joint pain made worse by mild exercise Diabetes, inflammatory bowel disease, renal disease or uncontrolled hypertension. Currently have or had a history of cardiovascular or pulmonary disease that would preclude the involvement in the performance of exercise History of myopathy (including congenital myopathies) History of neurological conditions related to spinal derangement, disk disease, peripheral neuropathies, tremor and rigidity Past medical history of hyperparathyroidism, kidney stones or rhabdomyolysis Currently receiving treatment for vitamin D deficiency Vitamin D level >30ng/mL Currently smoking

Ages Eligible for Study
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Minimum Age: 60 Years

Sexes Eligible for Study
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All

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: Other
Allocation: Randomized
Intervention Model: Factorial Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: vitamin D + aerobic training<br>vitamin D capsules every weekday (10,000IU/day) and exercise | Dietary Supplement: vitamin D<br>* 50,000IU/wk of vitamin D3<br>Other: aerobic training<br>* 7 days of treadmill training during the 13th week of study<br>|
| Active Comparator: vitamin D + no aerobic training<br>vitamin D capsules every weekday (10,000IU/day) and no exercise | Dietary Supplement: vitamin D<br>* 50,000IU/wk of vitamin D3<br>|
| Active Comparator: placebo + aerobic training<br>placebo capsule every weekday and exercise | Other: aerobic training<br>* 7 days of treadmill training during the 13th week of study<br>|
| No Intervention: placebo + no aerobic training<br>placebo capsule every weekday and no exercise | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| blood measure | vitamin D | Change from Baseline in vitamin D at 13 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| muscle lipid | Intramyocellular lipid and extramyocellular lipid will be assessed using magnetic resonance spectroscopy and fat segmentation. | baseline and 13 weeks after baseline | 
| muscle oxygen consumption | Local muscle tissue oxidative capacity will be measured using a novel hybrid diffuse optical instrument consisting of a near-infrared spectroscopy (NIRS) and a diffuse correlation spectroscopy (DCS) | baseline and 13 weeks after baseline | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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MRS, Vitamin D, 25(OH)D, Aerobic training, Near-infrared spectroscopy, Diffuse correlation spectroscopy