Effect of Vitamin D Supplementation on Muscle Mass and Function

Purdue University

Status and phase: Completed; Phase 4

Conditions: Inflammation; Insulin Resistance; Obesity

Treatments: Dietary Supplement: Vitamin D; Drug: Placebo

Study type: Interventional

Funder types: Other

Identifiers

NCT01199926

GSSI-VitD (0801006402)

Details and patient eligibility

About

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.

Full 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.

Enrollment: 34 patients

Sex: All

Ages: 18 to 35 years old

Volunteers: Accepts Healthy Volunteers

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).

Trial design

Primary purpose: Prevention

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Double Blind

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34 participants in 2 patient groups, including a placebo group

Vitamin D

Experimental group

Description:

Participants in this arm consumed a 4000 IU vitamin D supplement daily for 12 weeks while participating in a resistance exercise training program.

Treatment:

Dietary Supplement: Vitamin D

Placebo

Placebo Comparator group

Description:

Participants in this arm consumed a placebo (microcrystalline cellulose) daily for 12 weeks while participating in a resistance exercise training program.

Treatment:

Drug: Placebo

Dietary Supplement: Vitamin D