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| Name | Class |
|---|---|
| Uniformed Services University of the Health Sciences | FED |
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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.
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.
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| Label | Type | Description | Intervention Names |
|---|---|---|---|
| Calcium/Vitamin D Bar | Experimental | Dietary supplement consumed as 2 calcium and vitamin D fortified snack bars per day |
|
| Calcium/Vitamin D Pill | Experimental | Dietary supplement consumed as several capsules per day |
|
| Placebo Bar | Placebo Comparator | Placebo consumed as 2 isocaloric, unfortified snack bars per day |
|
| Placebo Pill | Placebo Comparator | Placebo consumed as several capsules per day |
|
| Name | Type | Description | Arm Group Labels | Other Names |
|---|---|---|---|---|
| Calcium/Vitamin D | Dietary Supplement | 2000 mg calcium and 1000 IU vitamin D administered daily as 8 pills or 2 fortified snack bars. |
|
| Measure | Description | Time Frame |
|---|---|---|
| Serum Bone Health Biomarkers (Composite) | 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) | Measures will be taken at the beginning and end of Initial Military Training (IMT) which is approximately 12 weeks |
| Measure | Description | Time Frame |
|---|---|---|
| Bone Strength Indices (Composite) | 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) |
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Inclusion Criteria:
Exclusion Criteria:
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| Name | Affiliation | Role |
|---|---|---|
| Erin Gaffney-Stomberg, Ph.D., R.D. | United States Army Research Institute of Environmental Medicine | Principal Investigator |
| Facility | Status | City | State | ZIP | Country | Contacts |
|---|---|---|---|---|---|---|
| Marine Corps Recruit Depot Parris Island | Parris Island | South Carolina | 29905 | United States |
| PubMed Identifier | Type | Citation | Retractions |
|---|---|---|---|
| 30615068 | Derived | Nakayama AT, Lutz LJ, Hruby A, Karl JP, McClung JP, Gaffney-Stomberg E. A dietary pattern rich in calcium, potassium, and protein is associated with tibia bone mineral content and strength in young adults entering initial military training. Am J Clin Nutr. 2019 Jan 1;109(1):186-196. doi: 10.1093/ajcn/nqy199. |
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| ID | Term |
|---|---|
| D002118 | Calcium |
| D014807 | Vitamin D |
| ID | Term |
|---|---|
| D008673 | Metals, Alkaline Earth |
| D004602 | Elements |
| D007287 | Inorganic Chemicals |
| D008670 | Metals |
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| Placebo | Dietary Supplement | Administered daily as 8 placebo pills or 2 unfortified snack bars. |
|
| Measures will be taken at the beginning and end of Initial Military Training (IMT) which is approximately 12 weeks |
| D001779 |
| Blood Coagulation Factors |
| D001685 | Biological Factors |
| D012632 | Secosteroids |
| D013256 | Steroids |
| D000072473 | Fused-Ring Compounds |
| D011083 | Polycyclic Compounds |