AlexanderBerenyi The sewer sludge comment was made in this video.Bioavailability of iron, zinc, and other trace minerals from vegetarian diets <a href="http://www.ajcn.org/content/78/3/633S.long">http://www.ajcn.org/content/78/3/633S.long</a> (A very fair review for both sides, in my opinion)Is the iron in spinach bioavailable?