I'm pretty sure there is a connection between circadian rhythm and ascorbate.

For example, a byproduct of ascorbate synthesis is hydrogen peroxide. So when we humans stopped synthesizing ascorbate, we began producing less hydrogen peroxide. Hydrogen peroxide is related to our circadian rhythm. It's only a small tweak, but maybe its effects are huge.

Also, collagen production is dependent on vitamin c (ascorbate). I think circadian rhythm is effected by collagen.

And parasites are believed to have their own rhythm. If they can turn off the hosts rhythm clock, and if its true that there are more parasitic cells in our bodies than there are our own cells, then we've been fully hacked.