IRON

What is iron?

All living organisms need iron. Iron is a mineral required for growth and development by our bodies [^[1]]. Iron is used to shuttle oxygen from the lungs all over the body, including to muscles and our brains. Beyond its involvement in oxygen transport, iron also plays a role in the immune response. We also use iron to make hormones [^[2]].

What does iron do in the body?                            

Iron is essential in biological processes such as oxygen transport, energy production, and the synthesis of nucleic acids like DNA. Iron is also involved in the body’s antiviral response; in a viral infection, the quickly-replicating viruses compete for iron with the person’s cells. Iron balance also influences the immune response. Low iron levels are associated with altered growth of immune cells, higher levels of pro-inflammatory molecules, and increased oxidative stress. In COVID-19, markers of low iron status can be both risk factors and prognostic indicators. These iron measures include ferritin, a protein used to store iron that stimulates pro-inflammatory compounds; high ferritin levels are linked to COVID-19 severity and mortality [^[3]].

How can iron help alleviate certain Long COVID symptoms and pathophysiology? 

Iron deficiency can be expected after COVID-19 and can contribute to long-term outcomes in terms of symptoms [^[4]]. Changes in iron balance can linger for at least two months after acute COVID-19 infection. Therefore, monitoring iron levels in patients with Long COVID is essential. Fatigue and difficulty breathing (dyspnea) are symptoms of iron deficiency, so supplementation with iron may help improve these symptoms in Long COVID patients with deficient iron. Iron deficiency is linked to impaired performance as well as non-resolving lung disorders in people who are post-COVID-19. Iron supplementation may also reduce inflammation and improve immune response to COVID-19 vaccination [^[5]]. In one study of Long COVID, iron deficiency was not associated with structural lung impairment but was linked to impaired stress resilience [^[6]].