Toggle Health Problems and D

Increased Bone strength during military training – with just 800 IU of vitamin D and Calcium – RCT April 2014

A calcium and vitamin D fortified food product improves bone adaptation during military training

The FASEB Journal, vol. 28 no. 1 Supplement 634.3 April 2014
Erin Gaffney-Stomberg 2, Laura Lutz 2, Julie Hughes 2, Nancy Murphy 2, Louis Marchitelli 2, Sonya Cable1, Andrew Young2 and James McClung2
1 Initital Military Training Center of Excellence Fort Eustis VA United States
2 US Army Research Institute of Environmental Medicine Natick MA United States

Stress fracture incidence during military training is high. Prior work suggests calcium (Ca) and vitamin D (vit D) intakes above the RDA may reduce fracture incidence in female trainees. How Ca and vit D affect measures of bone density and strength during initial military training (IMT) is not known. This randomized, double-blind, placebo-controlled trial was conducted to determine whether Ca and vit D (2000 mg and 800 IU) delivered as 2 snack bars daily throughout 9 wks of IMT improved trainee bone health. Measures of bone density pre- and post-IMT and strength were assessed using peripheral quantitative computed tomography (n=20 men, n=27 women). Tibia scans were performed on the non-dominant leg at 4, 14 and 66% of the segment length proximal to the distal end plate.

Several parameters increased during training including:

  • trabecular volumetric bone mineral density (vBMD) and bone strength index at the 4% site,
  • cortical vBMD at the 14% and 66% sites, and
  • stress strain index at the 66% site suggesting bone strength improved during IMT (all P<0.05).

Those who received Ca and vit D had

  • greater increases in total vBMD at the 4% site (3.0 ± 3.3 vs. 1.2 ± 2.4%; P<0.05)
  • as well as cortical thickness (1.9 ± 2.2 vs. 0.6 ± 1.8%; P<0.05) and
  • bone mineral content (1.6 ± 1.6 vs 0.6 ± 1.8%; P<0.05) at the 14% site.

These data indicate that Ca and vit D intakes above the RDA may support bone health during periods of high turnover such as IMT.

See also VitaminDWiki