I've seen popular science articles about the interaction between vitamin d and the free fructose in HFCS.
I haven't drilled down to scientific articles.
The same problem happens with invert sugar and agave nectar.
My understanding is that sucrose is a combination of fructose and glucose.
To make invert sugar, one processes the sucrose to separate the glucose from the fructose. this makes this sweeter. they do the same thing with agave nectar.
The free fructose acts like a radical which damages vitamin d.
I believe that the studies in this area are relatively new. If it is true then hfcs, invert sugar and other processed sugars are weeking our immune systems.
It might make an interesting article.
!BEER
RE: I Read Way Too Many Studies About Vitamin D So You Don't Have To