Submariners vitamin D levels continued to drop while on patrol (no surprise) – Dec 2013

Changes in vitamin D and matrix metalloproteinase-9 in submariners during a submerged patrol

Occup Environ Med doi:10.1136/oemed-2013-101793
A Baker 1,
C L Wood 2,
A M Wood 1,
P Timms 3,
A J Allsopp 1
1 Institute of Naval Medicine, Alverstoke, Hampshire, UK
2 Department of Child Health, Newcastle Hospitals Foundation Trust, Newcastle upon Tyne, UK
3 Department of Clinical Biochemistry, St Bartholomew's Hospital, London, UK
Correspondence to Dr C L Wood, Department of Child Health, Newcastle Hospitals Foundation Trust, Newcastle upon Tyne NE1 4LP, UK; claire.wood at ncl.ac.uk

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.

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Note: Tthe submariners were 9 nmols lower than shore-side to start with.
Suspect that their vitamin D levels had not recovered from the previous patrols.

Seem like the following photo of the UK submariners was just an experiment, not an on-going practice

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See also Vitamin D Life

• Vitamin D Supplementation in Underway Submariners PDF file , not web page
  the US NAVY paper in 2005 concluded that 400 IU was not enough for this occupation
• All items in category Shut-ins and Vitamin D 32 items
  Shut-ins: Arctic Explorers, Astronauts, prisoners, hospital patients, etc. need more vitamin D or more sunshine/UV
• 2000 IU daily raised vitamin D levels by 5 nanograms while on submarine patrol – July 2014
• Recommended increasing vitamin D for space flight – NASA Sept 2013
• Simulated Mars trip ran low on vitamin D (no supplements, no UV) – Sept 2019

See also web

• MMP9 Wikipedia
  are involved in the breakdown of extracellular matrix in normal physiological processes, such as embryonic development, reproduction, Angiogenesis, bone development, wound healing, cell migration, learning and memory, as well as in pathological processes, such as arthritis, intracerebral hemorrhage,2 and metastasis.
  MMPs such as MMP9 can be involved in the development of several human malignancies, as degradation of collagen IV in basement membrane and extracellular matrix facilitates tumor progression, including invasion, metastasis, growth and angiogenesis.