From the Guidelines
Taking iron supplements without iron deficiency is not recommended and can be potentially harmful. The latest guideline from the European Society for Clinical Nutrition and Metabolism (ESPen) states that iron supplementation in the presence of normal or even high ferritin values is not recommended and is potentially harmful 1. This is because excess iron can accumulate in the body's organs, particularly the liver, heart, and pancreas, potentially causing serious damage over time.
Some of the potential harms of taking iron supplements without iron deficiency include:
- Iron overload or hemochromatosis, which can lead to liver disease, heart problems, diabetes, and joint pain
- Common side effects such as constipation, nausea, vomiting, abdominal pain, and black stools 1
- Interference with the absorption of other minerals like zinc and reduction of the effectiveness of certain medications including antibiotics and thyroid medications
- Increased oxidative stress in the body due to the pro-oxidant properties of iron
It is essential to get iron levels tested before starting any supplement to avoid these potential harms. The ESPen guideline recommends treating iron deficiency only when it is associated with anemia and/or low ferritin levels 1. If iron supplementation is necessary, typical doses of oral iron supplements are 100-200 mg/day, in divided doses, and alternate day dosing may be associated with better iron resorption and fewer adverse effects 1.
From the FDA Drug Label
Warnings Do not exceed recommended dosage. ... Iron-containing products may occasionally cause constipation or diarrhea. The harms of taking iron supplement without iron deficiency include:
- Gastrointestinal discomfort such as nausea
- Constipation
- Diarrhea Accidental overdose of iron-containing products can be fatal, especially in children under 6 2.
From the Research
Harms of Taking Iron Supplements Without Iron Deficiency
- Gastrointestinal side effects, such as loose stools/diarrhea, hard stools/constipation, and abdominal pain, are common in individuals taking iron supplements without iron deficiency 3
- Increased risk of adverse effects, including nausea and vomiting, although the evidence is uncertain 3
- No significant difference in the incidence of gastrointestinal side effects comparing different doses of iron supplements 4
- Hepcidin upregulation by oral iron supplementation limits the absorption efficiency of high-dose oral iron supplementation, which may lead to increased iron stores and potential toxicity 5
- Iron supplementation without iron deficiency may lead to an increased risk of iron overload, which can cause damage to organs such as the liver, heart, and pancreas, although this is not directly stated in the provided studies
Mechanisms of Iron Supplementation
- Oral iron therapy is the first line of treatment for iron deficiency anemia, but its efficacy and safety in individuals without iron deficiency are uncertain 3, 6
- Vitamin C supplementation is not essential for patients with iron deficiency anemia, and its use with oral iron supplements does not provide additional benefits 6
- Parenteral iron formulations have altered iron treatment and enable rapid, safe total-dose iron replacement, but their use in individuals without iron deficiency is not recommended 5
Clinical Implications
- Iron deficiency anemia is a common cause of anemia in children and adolescents, especially in developing countries, and its prevention is important 7
- Primary prevention can be achieved by supplementary iron or iron fortification of staple foods, and dietary counseling and nutritional education are crucial 7
- Screening for iron deficiency anemia should be performed at approximately one year of age for healthy children, and selective laboratory screening should be performed at any age when risk factors for iron deficiency anemia have been identified 7