Vitamin D has an effect? Good to know. Does it need to be through supplements/food or does natural vitamin D work too? I presume supplements, because I absorb vitamin D at a much higher rate than average people and mosquitoes still bug me. But now that I think of it, I always hear people mention they are getting bitten before I start to get bothers by them. May just be coincidence though.
One thing I find that is fun is those electric rackets. You need to actively swat it around though, so when they get bad it's pretty much a full body workout just to keep them at bay lol.
One thing I tried which failed is to put a fan on a bug zapper. Bug zappers themselves don't work for mosquitoes, but figured if I put a fan they might get sucked in. You would place it at your feet. But in basic tests I did the fan was not powerful enough. It was only running at about 7 volts though, I just wired it straight into the lithium cell so when I turn the bug zapper on the fan turns on.
I want to try this experiment on a larger scale, I'm thinking a flat panel of metal grid that is similar to those zapper rackets, and it would have like 4 120mm fans on it and you would place it at your feet or around where you're sitting. Everyone would have one. It would create some air flow that would perhaps suck them through the grid of death.
I got that idea from an experiment a coworker tried at his house, he put a big net on a box fan, and they would all get captured in. You could do electric grid with a box fan, but my idea is that if it works with just computer fans it would be portable.
As far as bug repellent, there are some natural oils etc you can use, not only are they probably safer for your skin and don't make you all sticky, but I've found that they actually work better than OFF and Muskol etc. I can't recall any specific name/brands though.
I also heard that mosquitoes are attracted to black, so avoid anything black in the area you're at.