I can't I on my phone.
But what I meant was that females have a lighter skin tone in real life so that they can make extra vitamin k for a baby when pregnant.
Lighter skin helps with production of vitamin D, not vitamin K. Vitamin K is produced by intestinal bacteria.
As for gender differences, remember that folate is also critical in fetal development and ultraviolet light destroys folate reserves, so lighter skin might not help much overall.
Besides, humans on Nirn didn't evolve over millions of years, and redguards are a seagoing people with plenty of access to fish as a source of vitamin D.
Uh, no. Not sure where you heard that from, but thats not at all true.
I'm guessing he got it from a study by Nina Jablonski and George Chaplin: http://www.pbs.org/wgbh/evolution/library/07/3/text_pop/l_073_04.html but its about vitamin D, not K. The difference is only 3-4% though, so not really noticeable visually.