I don't know for sure, but since many of the causes depletion are relatively new inventions, like bread and Coke, I'd guess that most trad. h/gs had better zinc/magnesium than we did. There's a list of things that deplete magnesium if you scroll down here: http://www.krispin.com/magnes.html#Deficiency
I don't know much about zinc deficiency, except that it makes you really spacy, which some vegans mistake for spiritual enlightenment. I really want to try that stuff Dan John wrote about because I haven't noticed a difference from taking zinc this go around.
I know that higher amounts of zinc and vit. D mean you need less Mg.
As far as sleeping more, which you'll need to do if you want your endocrine, cardiovascular and immune systems to work properly, here's some suggestions that work for me when I follow them:
-go to bed at the same time each night, ideally no later than 11 (but definitely no later than 1 if at all possible)
-don't work out after 1 PM
-get outside around noon...this is supposed to supress melatonin
-use only candelight or soft, dimmed lights after sunset, or at least for the hour or so before bed. get vertical for about an hour before bed--I usually just do some light reading.
-if you have to stare at bright lights or computer screens late at night, you can wear rose glasses. i found this ridiculous looking pair at the hippie store (they're called "chakra glasses") but can't bring myself to wear them around other people.
-make sure your room is completely dark without any light at all, get heavy curtains and use electrical tape to cover bright blinky things.
-try to eat your last meal about three to six hours before bed, this is supposed to make sure you don't disrupt GH surges
-a slightly warm bath before bed can cool down the metabolism and relax the nervous system, let the water cool down a bit around the end
9+ hours of sleep in a completely dark room for three days in a row is supposed to cure sleep debt.
This is all stuff I've used, but most of my info is from this tabloid book Robb keeps raving about and from this tape: http://www.botanicalmedicine.org/Tapes/03sw/03sw17.htm
Magnesium right before bed helped me get to sleep a lot at first, but now I need to do all the other things too.