Dairy blocks iron uptake, vit C increases iron uptake. I hadn't looked into what aspect of the dairy caused the problems, but I could believe it was the calcium. When our daughter had a low iron issue, we fed her spaghetti w/ meat sauce (tomatos + beef) and lemonade to drink, just weekly for however many months before her next blood test. Punched her iron right up, was cool to see, and not constipating like an iron pill would have been.