TY - JOUR T1 - Changes in vitamin D and matrix metalloproteinase-9 in submariners during a submerged patrol JF - Occupational and Environmental Medicine JO - Occup Environ Med SP - 104 LP - 108 DO - 10.1136/oemed-2013-101793 VL - 71 IS - 2 AU - A Baker AU - C L Wood AU - A M Wood AU - P Timms AU - A J Allsopp Y1 - 2014/02/01 UR - http://oem.bmj.com/content/71/2/104.abstract N2 - Objectives To quantify changes in vitamin D and matrix metalloproteinase-9 (MMP9) in submariners over a single long patrol and compare the data to a group of non-deploying servicemen from their base port. Methods A prospective time-series analysis was performed. Blood samples were taken from 49 submariners deploying on patrol and 43 shore-side controls from the base port (naval officers from base or non-deploying submariners), following a winter ashore at latitude 56° north. Samples were drawn immediately before the submarine sailed, in January, and again in the final week of patrol 85 days later. Paired pre-patrol and late samples from each individual were assayed together and changes in vitamin D and MMP9 were assessed. Results Mean pre-patrol vitamin D concentrations were 58 and 49 nmol/L for the controls and submariners, respectively. Mean vitamin D concentrations increased in controls as expected (mean increase 12.6 nmol/L), but not in the submariners (mean decrease 1.6 nmol/L). MMP9 levels were significantly higher in submariners pre-patrol, and increased significantly during the patrol. There was a significant inverse correlation between MMP9 and vitamin D levels (r=−0.41, p=0.01). Conclusions This is the first study to quantify vitamin D and MMP levels in submariners. Circulating vitamin D concentrations on board were insufficient to prevent a rise in MMP. This has potential for adverse health effects and requires further study. ER -