Vit A: Dermatitis, photosensitivity reactions. Vit B
2: Yellow-orange urine discoloration. Fe: Anorexia; metallic taste; black/dark stools, bloating, constipation (may lead to fecal impaction particularly in the elderly), diarrhea, epigastric pain/discomfort, exacerbation of diarrhea (in patients w/ inflammatory bowel disease), flatulence, GI irritation, heartburn, nausea, stomach discomfort, vomiting; hemosiderosis clinically resembling hemochromatosis (in long-term administration of large amounts of Fe). Brewer's yeast: Allergic reactions; migraine headaches; flatulence, stomach discomfort.