Ferrous sulfate is a source of iron that is found in certain foods, such as red meat, fish, poultry, and certain beans and whole grains, or may be man-made and taken as a supplement. Iron is a mineral that is primarily responsible for the production of hemoglobin and myoglobin, two proteins that carry oxygen throughout the body. Hemoglobin provides oxygen to red blood cells, while myoglobin supplies oxygen to the muscles; therefore, an iron defiency may result in fatigue, weakness, brittle hair and nails, and fainting. If a person does not have enough iron in his or her body, he or she may be prescribed ferrous sulfate as a supplement to ensure the blood and muscles have an adequate oxygen supply. It is generally considered a safe supplement for most people, but certain ferrous sulfate side effects may occur that range from minor to potentially deadly.
The most common ferrous sulfate side effects tend to be mild and will usually not require any medical attention. When a person firsts begins taking the medication, he or she may experience slight nausea or abdominal pain. Ferrous sulfate may also affect bowel movements and may result in constipation or dark, discolored stool. If a liquid form of the medication is taken, it may also temporarily discolor the teeth. These side effects will usually subside with regular dosage of the medication as the body becomes used to it; however, if the side effects are prolonged or become worse, medical attention may then be recommended.
If proper dosage recommendations are not followed, more serious and potentially fatal ferrous sulfate side effects may occur. An overdose of the medication will typically result in severe abdominal pain, coughing up blood, difficulty breathing, dark brown vomit, pale skin, reduced pulse rate, and convulsions. Immediate emergency medical attention is advised if a ferrous sulfate overdose is suspected since it can be life-threatening, especially in children.
Although it is usually considered rare, if a person is allergic to the supplement, the reaction may also be serious and require emergency treatment. The most common ferrous sulfate side effects that occur in the event of an allergic reaction include an itchy red rash on the skin, sudden swelling in the face, tongue, lips, or throat, and having trouble breathing. In the event of these symptoms developing after taking ferrous sulfate, a medical professional should be contacted as soon as possible to restore breathing ability and prevent further complications or death.