http://ajcn.nutrition.org/content/75/5/887.full http://ajcn.nutrition.org/content/75/5/887.full sources http://ajcn.nutrition.org/content/75/5/887.full Dietary silicon intake and absorption http://ajcn.nutrition.org/content/75/5/887.full http://ajcn.nutrition.org/content/75/5/887.full sites and sources