Balanced iron levels support the brain and immune system. In excess, iron worsens inflammation and makes some viral infections more deadly. New data show that COVID-19 might alter iron markers, causing nerve damage and secondary bacterial infections. What does this mean for your iron intake during the pandemic?
This article is for informational purposes only. The current coronavirus outbreak is an ongoing event and certain details may change as new information comes to light. No effective or FDA-approved products are currently available for the treatment of the new coronavirus (also known as SARS-CoV-2 or 2019-nCoV), although research is still ongoing. For now, the best preventive measures you can take against COVID-19 are standard precautions, including social distancing, hand washing, and avoiding touching your face.
The Importance of Iron Amid COVID-19
Iron In Health & Disease
- Mount an effective immune response
- Build resistance to infections
- Produce red blood cells and energy
- Transport oxygen in the blood and muscles
- Protect cells against free radical damage, as a part of antioxidant enzymes (including catalases)
Because of these powerful roles, low iron levels can have detrimental health effects. On the other hand, excessive levels of iron can trigger reactive oxygen species that damage tissues and DNA [7, 8].
Therefore, it’s important to keep iron levels in balance.
Nearly 60% of iron inside the body is incorporated into hemoglobin, 10% into myoglobin, while the remaining 20 – 30% of iron is bound to special proteins like transferrin and ferritin. These proteins prevent free iron from causing oxidative damage in the body [1, 9, 10, 11, 12, 13, 14].
With this in mind, let’s take a look at one COVID-19 case that hints at the importance of iron balance amid the current pandemic.
A Case of COVID-19 Affecting Nerves & Iron Levels
The case outlined below is from a preliminary report (so-called preprint) that should be taken with a grain of salt since it is still awaiting publication. Findings from preprints remain inconclusive, unvalidated, and medically uncertain until they undergo peer review.
Scientists in China’s Hubei province, where the new coronavirus likely originated from, reported a case of an infected patient with inflammatory nerve problems and low iron levels .
The patient was a 66-year-old man with COVID-19 who developed partial paralysis due to spinal cord inflammation (post-infectious acute myelitis). He tested positive for the new coronavirus and negative for other microbes.
This is the first known case of coronavirus causing nerve damage. Most of the patient’s lab markers were normal, but he had low iron (1.8 umol/L). His inflammatory markers — ferritin, CRP, and IL-6 — were also high. Ferritin is an iron-storing protein that rises with inflammation and infection.
After diagnosis and treatment, his symptoms improved and his iron levels returned to normal. Two coronavirus swabs tests came back negative, and he was discharged.
What could explain these findings?
The Link Between Iron & Inflammation
Coronavirus infection has been linked with low red blood cells and hemoglobin in early stages. Later on, COVID-19 can cause widespread inflammation and “cytokine storms” that might injure nerves, increase ferritin, and lower iron [15, 16, 17, 18].
Other markers aside, low iron alone might be worrisome enough.
In one study, low iron increased the risk of dying in hospitalized patients with pneumonia, independent of other risk factors .
Low iron levels may also worsen nerve damage. The brain needs iron to function properly. Plus, nerve cells need iron to produce protective myelin sheaths without which they can’t communicate [4, 20, 21, 22].
Thus, it’s possible that coronavirus might lower iron blood levels, increasing the risk of further complications in some patients. That doesn’t mean supplementation is beneficial, though. The role of iron balance in COVID-19 deserves further research .
Hospital Superbugs & Ferritin
Another preprint found a link between secondary bacterial infections and high levels of ferritin, CRP, and procalcitonin in 20 COVID-19 patients. High levels of these inflammatory markers were also linked with very severe disease and worse outcomes .
How Does Iron Affect Viruses?
Iron Deficiency Increases Your Susceptibility to Infection
A study on over 6k children and their mothers associated iron deficiency during pregnancy with a reduced lung function in the offspring. Similarly, anemia was associated with an increased incidence of respiratory infections in 2 studies of almost 500 children [25, 26, 27].
Iron-fortified formulas reduced the incidence of respiratory infections, as well as symptoms of running nose, cough, and wheezing, in a trial on 260 babies .
In a trial on over 4k pregnant women and their newborn children, supplementation with iron alone or combined with folic acid (given to both) reduced upper but not lower respiratory infections .
Iron enhanced the activation of the immune system against cytomegalovirus in a cell-based study .
COVID-19 can cause dry cough, sputum, and lung damage .
In one trial on 22 women, iron deficiency was more common in women with chronic cough in a trial on 22 women. Iron sulfate supplementation improved the symptoms .
However, supplementation with zinc and iron had mixed effects in trials on thousands of babies. Combining iron with anti-inflammatory omega-3 fatty acids (EPA and DHA) gave the best results [35, 36, 37, 38].
Facemasks with Iron?
Nanoparticles with iron oxide reduced the replication and infectivity of influenza viruses by damaging their fatty envelope and enzymes. Their addition to facemasks reduced the loads of several influenza viruses that cause the flu (H1N1, H5N1, and H7N9) .
The new coronavirus also has a fatty envelope, which helps it stick to and invade host cells. Compounds that disrupt envelopes may work by preventing coronavirus from entering cells. However, iron nanoparticles haven’t yet been tested against the new virus .
Too Much Iron Might Worsen Infection
Although having enough iron can be protective, having too much might do more harm than good.
Several viruses, including hepatitis C, enter the cells by recognizing an iron entry protein (transferrin receptor). Once inside the body, viruses and bacteria also need iron to multiply [40, 41, 42].
High blood iron levels increased the risk of persistent human papillomavirus (HPV) infection in a study on over 2500 low-income women .
According to a study on 36 people, stable cystic fibrosis patients are more likely to have high sputum iron and to suffer from persistent infections .
In a study on over 1k people, HIV infection increased susceptibility to tuberculosis by shifting iron balance. Iron seemed to move from the blood into immune cells, causing damage. In turn, HIV patients had inflammation, high ferritin, and anemia. Since the same lab markers are altered in COVID-19 patients, somewhat overlapping mechanisms might be at work .
When low blood iron is due to its redistribution in the body, like in HIV patients, supplementation isn’t usually recommended .
The effects of iron overload on the 2019 coronavirus and its complications haven’t been tested.
Can Mild Iron Deficiency Ever be Beneficial?
Moderate iron deficiency was suggested to protect against respiratory infections in a study on 283 children .
Similarly, iron deficiency seemed to protect from malaria in a study on almost 2700 Kenyan and Ugandan children. This study was of low quality and had several limitations, though .
Scientists said a trade-off might be at work: mild deficiency deprives microbes of iron but increases the risk of infection by compromising immune protection .
On the other hand, even mild iron deficiency has many negative effects. Unless advised so by a doctor, don’t try to lower your daily iron intake.
In a study of over 300 people, genetic variants in the genes that help make ferritin and heme oxygenase were associated with acute respiratory distress syndrome (ARDS). COVID-19 can also cause life-threatening ARDS [54, 55].
Dosage & Precautions
- meat and poultry, including organ meats like liver, heart, kidney, and blood
- fish, including shellfish and sardines
Plant-based foods that are high in iron in the non-heme form (but may also be high in substances that prevent iron absorption) include:
- pulses, including chickpeas, beans, peas, and lentils
- seeds, including sesame and pumpkin seeds
- green leafy vegetables, including broccoli and kale
Recommended Daily Allowance (RDA)
Women of childbearing age (19 – 50 yrs) should get around 18 mg/day.
The amount of iron absorbed from the diet may not be enough to meet individual requirements in some populations, such as in small children, pregnant women, and people who engage in intense exercise [62, 63].
If it’s not possible for you to up the amount of absorbable iron in your diet, your doctor may recommend supplements to prevent iron deficiency anemia. This is often the case in children 6-24 months of age and pregnant women [64, 65, 66].
Your doctor may also prescribe iron if you already have iron deficiency anemia . Keep in mind that it may take several months of supplementation to correct iron deficiency.
For treating iron deficiency anemia, a dose of 60-120 mg of elemental iron (amount of actual iron in the supplement) from ferrous sulfate is recommended per day for a minimum of 3 months in adolescents and adults, including pregnant women .
Zinc deficiency is associated with iron deficiency anemia and worsens it. If you take both iron and zinc supplements, take them with food. Taking these two nutrients together on an empty stomach is not a good idea since iron may block zinc absorption [70, 71, 72].
Precautions & Side Effects
Preliminary data suggest that coronavirus may alter iron balance in the body. Low blood iron and high ferritin levels have been linked with worse COVID-10 outcomes, but this has yet to be confirmed.
Iron is an important dietary nutrient that we need in just the right amounts. Too much iron might worsen inflammation, which can make COVID-19 more serious. On the other hand, iron deficiency may increase susceptibility to infection.
Make sure to get enough iron from both vegetables and meat as part of a healthy diet. Don’t supplement unless recommended by a doctor.
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