the phytoestrogens are much weaker physiologically than mammalian estrogen.
So I always get rather confused when articles state the horrors of soy formula.

Soy WILL complex out zinc however, and that is not good.

If formula is the ONLY source of food, I would be concerned as well. If it is a supplement to a toddler, I would expect less effect.

The estrogen issues is complex... try to understand THIS:
http://toxsci.oxfordjournals.org/cgi...stract/80/1/14

http://www.ajcn.org/cgi/content/full/79/3/396

on rats:
http://findarticles.com/p/articles/m...2/ai_n14816156

This article gives potencies of various "estrogens"
http://findarticles.com/p/articles/m...32/ai_20153477
Genestein is about 1000 times less potent than Estradiol.
I have read "thousand" before in earlier papers, and perhaps more than a thousand.

I have often wondered how much estrogen we get from meat. ???
Also the environment is full of estrogenic compounds as well. (water)
Some fire retardants are anti-thyroid in actions, for example.

Not an easy subject to understand, with many conflicting studies so far.