Iron deficiency is one of the more common causes of restless legs syndrome (RLS). If you suffer from recurrent discomfort in your legs when you lie down to sleep — a feeling relieved by movement — you may be seeking treatment options. For those with low blood iron levels (as shown in a laboratory test), taking iron may be helpful. This may be especially important in women who still have regular menses. How do you use iron supplements to treat restless legs?
Tests to Determine Iron Levels in Restless Legs
It's often difficult to determine the cause of restless legs syndrome, leading to the label of "idiopathic" (meaning that the cause is unknown). There are also identified causes that can lead to RLS, with the most common by far being iron deficiency. In order to determine if iron deficiency is causing your RLS, your doctor will need to order a blood test.
To determine if you have iron deficiency, one of the most important tests is serum ferritin, a measure of your body’s iron stores. When these levels are less than 50 mcg per liter of blood, it is recommended to take an iron supplement by mouth. This level may be low, even without other signs of anemia.
What Iron Supplements to Take for RLS
There are a number of over-the-counter options for iron supplements. Most will contain the word ferrous, indicating the presence of iron, but the second word describing the compound may vary. For example, it may contain ferrous sulfate, or ferrous fumarate, or ferrous gluconate. Any of these options is acceptable. As for the precise dose needed, this is based on your ferritin level, and should be discussed with your doctor.
How to Take Iron and Common Side Effects
It is recommended that the iron supplement be taken on an empty stomach to aid absorption; it should also be taken with a dose of vitamin C, which helps the body absorb the iron and will allow more of the supplement to enter your bloodstream.
The most common side effect associated with taking iron tablets is constipation. If you experience an upset stomach or constipation, consider taking an over-the-counter stool softener or laxative. Common options include Colace (or docusate), MiraLax, and Senokot. Alternatively, it may be necessary to reduce the iron dose.
Diet Changes as an Alternative to Iron Pills
If you decide that you do not wish to take an iron supplement, there are alternative ways you can increase your daily intake of iron. The easiest is to increase your consumption of red meat. Turkey or chicken giblets, shellfish, and liver are also rich in iron. These dietary changes may not be an option for everyone, especially vegetarians or vegans. Fortunately, there are vegetables, fruits, and legumes that are also rich in iron:
- Dark, leafy greens (spinach, collards)
- Dried prunes and raisins
- Beans, lentils, chickpeas, and soybeans
- Other iron-fortified foods (like cereals)
When to Recheck Your Iron Level
No matter how you choose to supplement iron in your diet, your doctor will likely want to recheck your ferritin level in the future to ensure that it has improved. If you find that your restless legs symptoms are relieved, you may be assured that it is helping. Your doctor will want to make certain that you do not take too much iron, resulting in iron overload and a condition called hemochromatosis. Regular follow-up with your doctor with routine blood-work will be important.
Hening, WA, Buchfuhrer, MJ, and Lee, HB. "Clinical Management of Restless Legs Syndrome." Professional Communications, Inc., First Edition, 2008, pp. 220-221.