<p>Dark stools are usual during iron therapy and nausea and other symptoms of gastrointestinal irritation such as anorexia, vomiting, discomfort, constipation and diarrhoea are sometimes encountered. Zinc may also produce a gastrointestinal upset. These timed-release capsules are designed to reduce the possibility of gastrointestinal irritation. There have been rare reports of allergic reactions</p>