From the Guidelines
Ferrous sulfate is the most effective oral iron supplement for treating Restless Legs Syndrome (RLS) and Periodic Limb Movements (PLMs), as suggested by the American Academy of Sleep Medicine 1. When considering iron supplements for RLS and PLMs, it's essential to note that ferrous sulfate is preferred over other options due to its efficacy and moderate certainty of evidence. The recommended dose is typically 325 mg containing 65 mg of elemental iron, taken once or twice daily.
Key Considerations for Iron Supplementation
- Iron supplementation works best for patients with low ferritin levels (below 75 ng/mL), as iron deficiency is a common underlying cause of RLS and PLMs 1.
- The therapeutic goal is to raise ferritin levels above 100 ng/mL, which often requires 3-6 months of consistent supplementation.
- Common side effects include constipation, nausea, and black stools.
- It's crucial to have iron levels monitored regularly through blood tests, as excessive iron can be harmful.
Administration and Absorption
- Iron supplements are most effective when taken on an empty stomach with vitamin C (such as orange juice) to enhance absorption 1.
- If stomach upset occurs, they can be taken with food.
- Alternative oral preparations or parenteral iron should be considered if ferrous sulfate is not tolerated 1.
Severe Cases or Intolerance
- For severe cases or when oral supplements aren't tolerated, intravenous iron formulations like iron sucrose or ferric carboxymaltose might be recommended by a healthcare provider 1.
From the Research
Iron Oral Supplements for RLS and PLMs
- Iron deficiency is a common cause of Restless Legs Syndrome (RLS) and Periodic Limb Movements (PLMs) 2, 3, 4, 5
- Iron replacement therapy is a first-line management option for RLS, especially in patients with evidence of reduced body iron stores 2, 3
- Oral iron supplements have been shown to improve RLS symptoms, including restlessness and uncomfortable leg sensations 3
- The use of iron supplements may also improve quality of life, although the evidence is limited and the certainty of this outcome is moderate to low 3
Types of Iron Oral Supplements
- There is no specific recommendation for a particular type of iron oral supplement for RLS and PLMs 3, 4, 5, 6
- However, iron supplements with high bioavailability, such as ferrous sulfate or ferrous gluconate, may be more effective in improving RLS symptoms 3
Dosage and Duration of Iron Oral Supplements
- The optimal dosage and duration of iron oral supplements for RLS and PLMs are not well established 3, 4, 5, 6
- However, studies suggest that iron supplements should be taken for at least 2-12 weeks to assess their effectiveness in improving RLS symptoms 3
Safety and Efficacy of Iron Oral Supplements
- Iron oral supplements are generally well-tolerated and safe, with a low risk of adverse events 3
- However, high doses of iron supplements can cause gastrointestinal side effects, such as nausea, vomiting, and diarrhea 3
- The efficacy of iron oral supplements in improving RLS symptoms is moderate, with a significant reduction in restlessness and uncomfortable leg sensations compared to placebo 3