Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinchttps://www.nap.edu/download/10026 While they have indicators to diagnose copper deficiency, there is no report that they used them to see if their recommendation of 0.9 mg causes copper deficiency! What they did was use incomplete calculations … Continue reading How the Government Determined the RDA for copper at 0.9 Milligrams