Bone Health, Nutrition Status
Conditions
Keywords
Calcium, Vitamin D
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.
Interventions
DIETARY_SUPPLEMENTCalcium/Vitamin D
2000 mg calcium and 1000 IU vitamin D administered daily as 8 pills or 2 fortified snack bars.
DIETARY_SUPPLEMENTPlacebo
Administered daily as 8 placebo pills or 2 unfortified snack bars.
Sponsors
Uniformed Services University of the Health Sciences
United States Army Research Institute of Environmental Medicine
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
QUADRUPLE (Subject, Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
17 Years to No maximum
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| 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) |
Countries
United States
Outcome results
None listed