Vitamin D Supplementation D_SAF Pilot Study

This study is a randomised control trial (RCT) pilot study to determine the appropriate vitamin D dose for the main study. The pilot study includes three matched groups, which will form two vitamin D supplementation groups (at 25,000 IU and 50,000 IU every two months), and a third placebo supplementation group. The aim was to develop an appropriate supplementation regimen that was compatible with recruit training and maintained serum vitamin D (25OHD) status above 50 nmol/l during recruit training.