Here's a shout-out to everyone who isn't getting enough vitamin D while living on Earth's sunny surface! Almost nobody is getting enough these days because we're not running around half-naked in the right regions or eating optimal foods, even the 400IU recommendations by most governments are just sufficient to prevent rickets. For a decade the best recommendations have been to take 2000-4000IU in supplement form.

If *that* is the big concern about moving underground, put me on the next train down!