What should happen if the requirements of health and safety were to conflict with the requirements of modesty?

Let us suppose that at some time in the future, followers of Islam find their way to planets other than earth, and let us suppose that on one of these planets, in order to maintain proper levels of vitamin D, people must expose as much of their bodies as practical to the light of a different sun that emits far less ultraviolet light than our own sun, for as much of the daylight hours as possible, as no foods or supplements containing any vitamin D at all are available. Should a person maintain properly modest attire according to Islam as we know it now, in such an environment they would surely develop Vitamin D deficiency diseases. It should not be considered possible to leave such an environment - the journey would be one-way, and neither would it have been possible to anticipate prior to arrival on the new planet that such conditions might exist without vitamin D supplements being available. I have no doubt that exposing one's whole body to the light of the sun - and since work must still be done, to the view of other people - all day would be considered very immodest, but how could this as a necessity of health in this peculiar situation be reconciled with the Islamic requirement to remain modesty dressed? I would appreciate answers that reference appropriate scripture.