mrsd,
Thank you for your post. Very interesting information.
I didn't know about the effects of fructose on trapping phosphate. Here's an interesting study on soft drink consumption:
http://www.sciencenews.org/articles/20050618/food.asp
You quoted a study: "A recent study of 11 adult men found that a diet high in fructose (20% of total calories) resulted in increased urinary loss of phosphorus and a negative phosphorus balance (i.e., daily loss of phosphorus was higher than daily intake). This effect was more pronounced if the diet was also low in magnesium (3)." According to the science news article there are teenagers who may be getting 1/3 or more of their calories from soft drinks and fruit juices. I would be will to bet that their diets are low in magnesium as well.
If people consume fruit, soft drinks, fruit juice and energy bars (high fructose corn syrup is the first ingredient listed in one Power Bar I looked at), they are getting an awful lot of fructose.
I understand that hypophosphatemia is unlikely to occur in the US these days, although I am sure that it still happens. It is just very interesting to find that only now are we discovering that lack of vitamin D does not cause rickets - something that virtually no medical doctor these days knows yet, I would guess.