From the Guidelines
Iron deficiency can contribute to restless legs syndrome (RLS) due to its role in brain dopamine function, which is affected by the blood-brain barrier, and I recommend oral iron supplementation, specifically ferrous sulfate, as the first line of treatment for RLS symptoms. For optimal symptom relief, target a serum ferritin level above 75 ng/mL 1. Iron is essential for dopamine production and function in the brain, and low iron levels can disrupt this system, leading to RLS symptoms. The blood-brain barrier regulates iron transport to the brain, and dysfunction in this transport mechanism may explain why some people with normal blood iron levels still experience RLS.
Some key points to consider when treating RLS with iron supplementation include:
- Take iron supplements between meals to enhance absorption
- Avoid taking iron supplements with calcium, dairy, coffee, or tea, as these can inhibit absorption
- Be aware of potential side effects like constipation and stomach upset
- If symptoms persist despite iron therapy, consult a healthcare provider as prescription medications like dopamine agonists (pramipexole, ropinirole) may be necessary, although their use is not recommended as a first-line treatment due to the risk of augmentation 1.
It's also important to note that the American Academy of Sleep Medicine (AASM) suggests the use of ferrous sulfate over no ferrous sulfate in patients with appropriate iron status, with a conditional recommendation and moderate certainty of evidence 1. Additionally, the AASM recommends testing serum iron studies, including ferritin and transferrin saturation, to guide the decision to use oral or intravenous (IV) iron treatment 1.
From the Research
Iron and Restless Legs Syndrome
- Restless legs syndrome (RLS) is a common neurologic disorder that is associated with peripheral iron deficiency in a subgroup of patients 2, 3, 4, 5, 6
- Iron deficiency is a known cause of RLS, and iron supplementation is often used as a treatment 2, 3, 4, 5, 6
- The pathogenesis of RLS remains unclear, but it is likely to involve central nervous system dopaminergic dysfunction, as well as other undefined contributing mechanisms 2
Blood Drain Barrier and Restless Legs Syndrome
- There is no direct evidence in the provided studies to suggest a link between the blood drain barrier and restless legs syndrome 2, 3, 4, 5, 6
- However, iron deficiency, which is associated with RLS, can affect the blood-brain barrier and lead to neurological symptoms 2, 3, 4, 5, 6
Treatment of Restless Legs Syndrome with Iron
- Iron supplementation, either oral or intravenous, has been shown to be effective in improving RLS symptoms in some patients 3, 4, 5, 6
- A systematic review and meta-analysis found that iron therapy was associated with a significant decrease in RLS symptoms, as measured by the International Restless Legs Syndrome score (IRLSS) 4
- Another study found that iron supplementation improved RLS symptoms in patients with iron deficiency anemia, with no significant difference between oral and intravenous iron 6
- However, the evidence is not consistent, and some studies have found no clear benefit of iron therapy for RLS 3, 5
Key Findings
- Iron deficiency is a known cause of RLS, and iron supplementation is often used as a treatment 2, 3, 4, 5, 6
- Iron supplementation has been shown to be effective in improving RLS symptoms in some patients, but the evidence is not consistent 3, 4, 5, 6
- Further research is needed to determine the optimal treatment for RLS and to understand the relationship between iron deficiency and RLS 2, 3, 4, 5, 6