https://www.scientificamerican.com/article/does-eating-too-much-fiber-cause-mineral-deficiencies/

Today’s topic was proposed by Lisa, who called in on the Nutrition Diva Listener line with this great question:

“Hey Monica, I have a question about whether too much fiber causes nutrient deficiencies. I read that an excessive amount of fiber binds with minerals including calcium, magnesium, zinc, and iron preventing them from being absorbed by the body. Is there validity to these claims? What can we consider to be excessive fiber?”