Efficacy of a Once Daily Calcium and Vitamin D Fortified Food Product to Improve Bone Microarchitecture

Overview

The primary objective of this randomized, double-blind, placebo controlled trial is to determine the efficacy of a once per day calcium (1000mg) and vitamin D (1000IU) fortified food product on bone turnover markers, including parathyroid hormone (PTH) and microarchitecture during Army basic military training (BCT). The investigators hypothesize that consumption of a once daily calcium and vitamin D fortified food product will stabilize PTH and contribute to improved bone microarchitecture compared to placebo. The results will determine the efficacy of daily supplementation with calcium and vitamin D on bone turnover markers as well as provide novel data regarding microarchitectural changes during BCT as assessed by high resolution peripheral computed tomography (HRpQCT) scanning.

Stress fractures may affect up to 2-5% of male and 8-21% of female Soldiers during training, resulting in attrition in up to 60% of affected personnel. A recent report indicates that supplemental calcium (2000mg) and vitamin D (800-1000IU) stabilizes PTH, increases tibia volumetric bone mineral density in male and female recruits undergoing Army BCT, and reduces stress fracture incidence by up to 20% in female Nacy recruits. Bone macroarchitecture has been measured in response to basic training however, the resolution of standard peripheral quantitative computed tomography (pQCT) is insufficient for assessment of microarchitectural changes, which may underlie the pathophysiology of stress fracture. With the use of HRpQCT this study will allow the investigators to evaluate microarchitectural changes within the bone tissue and assess the efficacy of a moderate daily dose of calcium and vitamin D to support bone health during BCT.