Hi, I ve been having black stools recently for the past 3 weeks, I have been taking zinc, magnesium , BCAA, green tea extract, vitamin C and milk thistle for about a month and I had checked the nutrition fact sheets about this supplements and none of them include iron in it. I am also on a low-carb with moderate protein and fiber diet. I ve been wondering if the black colour present in my stool is base on the supplements and diet i am having or there is a rupture in my stomach/gastric. Please help! Thank you. Regards, Zachary