Vitamin D status, dietary intake, and bone turnover in female Soldiers during military training: a longitudinal study
Laura J Lutz, J Philip Karl, Jennifer C Rood, Sonya J Cable, Kelly W Williams, Andrew J Young and James P McClung
Journal of the International Society of Sports Nutrition 2012, 9:38 doi:10.1186/1550-2783-9-38
Published: 6 August 2012
Background: Vitamin D is an essential nutrient for maintaining bone health, to include protecting against stress fracture during periods of rapid bone turnover. The objective of this longitudinal, observational study was to assess vitamin D status, biomarkers of bone turnover, and vitamin D and calcium intake in female Soldiers (n = 91) during US Army basic combat training (BCT).
Methods: Anthropometric, biological and dietary intake data were collected at wk 0, 3, 6, and 9 of the 10 wk BCT course. Mixed models repeated measures ANOVAs were used to assess main effects of time, race, and time-by-race interactions.
Results: White volunteers experienced a decrease in serum 25(OH)D levels, whereas non-white volunteers experienced an increase during BCT.
However, serum 25(OH)D levels were lower in non-whites than whites at all timepoints (P-interaction < 0.05).
Group mean PTH levels increased (P < 0.05) during the first 3 wk of training, remained elevated for the duration of BCT, and were higher in non-whites compared to whites (P-race < 0.05).
Biomarkers of both bone formation (bone alkaline phosphatase and procollagen I N-terminal peptide) and resorption (tartrate-resistant acid phosphatase and C-terminal telopeptide) increased (P < 0.05) during BCT, indicating increased bone turnover. Estimated daily intakes of vitamin D and calcium were below recommended levels (15 mug and 1000 mg/day, respectively), both before (group mean +/- SEM; 3.9 mug/d +/- 0.4 and 887 mg/d +/- 67) and during BCT (4.1 mug/d +/- 0.3 and 882 mg/d +/- 51).
Conclusions: These findings demonstrate that female Soldiers experience dynamic changes in vitamin D status coupled with increased bone turnover and potentially inadequate vitamin D and calcium intake during military training.
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- Vitamin D levels dropped after training for white, but not black females April 2010
Perhaps the whites and Hispanics wore sunscreen
- All items in category Women and vitamin D
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