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

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.

Inclusion criteria

• Female or male US Army recruits beginning Army basic combat training at Fort Jackson, South Carolina

Exclusion criteria

• Pregnant or breastfeeding
• History of kidney stones or kidney disease
• History of amenorrhea
• History or endocrine disorders
• History of bone modifying disorders
• Currently taking, or have taken glucocorticoid drugs in the 2 years prior to study participation
• Currently diagnosed as anemic by healthcare professional
• Those allergic to any component of the snack bar