Evaluation of Calcium and Vitamin D Supplementation During Marine Corps Training

Not Applicable

Completed

• Conditions: Bone Health; Nutrition Status
• Interventions: Dietary Supplement: Calcium/Vitamin D; Dietary Supplement: Placebo

• Registration Number: NCT02636348
• Lead Sponsor: United States Army Research Institute of Environmental Medicine

Brief Summary

The primary objective of this randomized, double-blind, placebo-controlled trial is to determine the efficacy and effectiveness of Ca and vitamin D supplementation provided daily throughout Marine Corps recruit training on maintenance of PTH and indices of bone strength in Marine Corps recruits. The investigators hypothesize that Ca+D will prevent elevations in PTH and result in greater increases in indices of bone strength compared to placebo.

Detailed Description

Military recruits undergoing initial military training (IMT) are 17 times more likely to develop stress fractures compared to active duty service members. Up to 800 male and female recruits will be enrolled at the MCRD, Parris Island, SC over two seasons (summer/fall and winter/spring) in order to account for seasonal variation in vitamin D status. Ca (2000 mg/d) and vitamin D (1000 IU/d) will be supplied as either capsules or a fortified food product daily throughout training. This study will provide novel data for the military, medical and scientific communities regarding the relationship between Ca and vitamin D supplementation and biomarkers of immune function, and the requirements for calcium and vitamin D to support bone health during IMT.

Study Timeline

• Study First Submitted: 2015-06-24
• Study Start: 2015-07
• Study First Submitted QC: 2015-12-16
• Study First Posted: 2015-12-21
• Primary Completion: 2016-04
• Status Verified: 2016-10
• Study Completion: 2016-10
• Last Update Submitted: 2016-10-27
• Last Update Posted: 2016-10-28

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 380

Inclusion Criteria

• Male or female Marine Corps recruit at least 17 years of age.

Exclusion Criteria

• Pregnant or breastfeeding
• History of kidney stones or kidney disease
• History of endocrine disorders
• Allergies to any component of the food product bar

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Calcium/Vitamin D Pill	Calcium/Vitamin D	Dietary supplement consumed as several capsules per day
Placebo Pill	Placebo	Placebo consumed as several capsules per day
Placebo Bar	Placebo	Placebo consumed as 2 isocaloric, unfortified snack bars per day
Calcium/Vitamin D Bar	Calcium/Vitamin D	Dietary supplement consumed as 2 calcium and vitamin D fortified snack bars per day

Primary Outcome Measures

Name	Time	Method
Serum Bone Health Biomarkers (Composite)	Measures will be taken at the beginning and end of Initial Military Training (IMT) which is approximately 12 weeks	Effect of calcium/vitamin D on the following serum biomarkers: 25(OH)D (ng/ml), parathyroid hormone (PTH) (pg/ml), C-telopeptide cross-links of type 1 collagen (CTX) (ng/ml), tartrate-resistant acid phosphatase (TRAP) (U/L), bone alkaline phosphatase (BAP) (ug/L), procollagen I N-terminal peptide (P1NP) (ug/L)

Secondary Outcome Measures

Name	Time	Method
Bone Strength Indices (Composite)	Measures will be taken at the beginning and end of Initial Military Training (IMT) which is approximately 12 weeks	Effect of calcium/vitamin D on the following indices of bone strength as assessed by peripheral quantitative computed tomography (pQCT): volumetric bone mineral density (vBMD) (mg/cm3), bone strength index (BSI) (mg/mm4), cortical bone mineral content (Crt BMC) (mg/mm), cortical volumetric bone mineral density (Crt vBMD) (mg/cm3), strength strain index (SSI) (no units)

Trial Locations

Locations (1)

Marine Corps Recruit Depot Parris Island; 🇺🇸 Parris Island, South Carolina, United States