Vitamin D status, bone mineral density and risk of stress fracture in New Zealand

Vitamin D and iron deficiency in females has been linked to both physical and mental fatigue, and therefore, injury. This was a two year study assessing female army recruits during basic training.

Background and context

Decreases in iron status have been reported in military women during initial training periods of 8 to 10 weeks. The study aimed to characterise iron status and associations with physical performance in female New Zealand Army recruits during a 16-week basic combat training course.

Results and conclusions

  • Serum ferritin (sFer) (56·6 (sd 33·7) v. 38·4 (sd 23·8) µg/l) and Transferrin Saturation (38·8 (sd 13·9) v. 34·4 (sd 11·5) %) decreased (P<0·001 and P=0·014, respectively).
  • Soluble transferrin receptor (1·21 (sd 0·27) v. 1·39 (sd 0·35) mg/l) and RDW (12·8 (sd 0·6) v. 13·2 (sd 0·7) %) increased (P<0·001) from baseline to end.
  • Hb (140·6 (sd 7·5) v. 142·9 (sd 7·9) g/l) increased (P=0·009) during basic combat training.
  • At the end of basic training, Soluble transferrin receptor (sTfR) was positively (r 0·29, P=0·012) and Transferrin Saturation (TS) inversely associated (r –0·32, P=0·005) with midpoint run time.

There were no significant correlations between iron status and press-ups. Storage and functional iron parameters indicated a decline in iron status in female recruits during basic combat training. Correlations between tissue-iron indicators and run times suggest impaired aerobic fitness.

Optimal iron status appears paramount for success in female recruits during military training.

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