I'm new to vaping (3 weeks) and a lot of my issues are specific to me probably, but I still wanted to chime in here because dehydration from vaping has also been my concern.
I have an autoimmune disease that dries the mucous membranes (among doing other nasty things, such as giving me a predisposition to "lung involvement," which translates to the fact that I have had severe, ICU-demanding pneumonia twice as well as very painful pleurisy to follow). My eyes are always dry, for which I use Refresh drops (the kind you can take all day, the little cartridges without preservatives in them), have had tear duct plugs inserted (so moisture stays on my eyes instead of draining off), use an Orajel mouth gel at night, treat my humidifier like a deity, and most importantly keep water with me all the time. I drink in excess of three liters a day and usually just have just one cup of coffee in the morning.
I'm wasn't supposed to smoke at all before, but i did because i was addicted, and now I'm a new vaper ( I don't want to get lung cancer OR go back to the ER with pneumonia). At first I bought a bunch of e-juices, all PG, not understanding about PG vs VG. I immediately noticed that the dryness was a lot worse! Mainly in my eyes and also in the mouth. I've read about others' issues with dehydration on other parts of this forum. I worried that, even after quitting cigarettes finally, I wouldn't even be able to vape despite avoiding the demon tobacco, because of these dryness issues. Blending PG with VG (up to about 50/50) has really helped me.
In addition to experimenting with PG/VG blends, I have been drinking EVEN MORE water than before ... And I have to say that all is now generally well with me. I will always have dryness problems, and I know that vaping is much better for me overall than smoking. So now I drink even more water, and I drink an extra glass of water before bed especially (I always go to bed with about a liter of water that I drink off and on during the night). The main thing I do too, though, is make sure that I always rinse my mouth out after the last vape of the night. Someone suggested that in a thread on the main "general e-cigarettes" part of these forums, and that has really helped me. I have noticed that I am back to the general dryness that I always get, and not the seemingly extra amount of dehydration I was getting when I started vaping.
I also upped my vitamin B intake and my vitamin D dose. I tend toward anemia, and let me remind you, I am not a doctor in any way shape or form, but I have been dealing with dehydration and dryness issues for awhile now, and I have to say that even just a little extra water helps, as does the mouth rinsing and the vits.
I think you can probably get on top of the dehydration issue if you just really keep aware of your water intake. If someone like me, with my own unique autoimmune problems and the fact that I also live in a dry climate, can do it ... I think that others can do it too. Experiment with PG/VG mixes and always keep water handy. It's possible that all along you have simply not been hydrating sufficiently without even knowing it.
