Here we are looking for more subtle signs of disturbances in the processing of iron in the body.
Iron is important for certain steps in making dopamine in the brain.
A low ferritin level should be treated because this will help some patients with RLS symptoms.
Augmentation (which is when symptoms start to get worse and more frequent again after an initially good response to dopaminergic drugs) is commonly linked to poor iron transport or absorption (your GP or specialist may not know this). Because poor iron processing may not show up on the basic tests, we recommend also testing for Transferrin Saturation. This can reveal a problem even when the Ferritin is normal.
There is an example of a patientwho developed augmentation, but had normal iron and Ferritin levels. Looking deeper, further tests showed her transferrin saturation level was low however. When she was treated with iron supplements she was able to stop her dopaminergic medication.
Disturbed iron processing can also be an indication of chronic inflammation somewhere in the body, so this test should be done together with the hs-CRP test.