During times of infection our cells can shift trace minerals into or out of storage in a defensive mechanism against the pathogens. Some may be harmed by losing access to a mineral necessary for their survival and other types may be harmed by increased levels, toxic to the pathogen.
Iron is stored and not made into hemoglobin during times of inflammation, possibly because of the survival strategies against pathogens. During chronic inflammation however the lack of hemoglobin causes a type of anemia that isn't related to a lack of iron in the diet or other B vitamins. Anemia causes symptoms of fatigue and possibly feeling cold and more confused or having difficulty concentrating. (Trace Metals, page 210) (Anaemia of Chronic Disease: An In Depth Review)
Lab tests to consider for diagnostic purposes are listed in a copy of a publication by Morley Robbins (biomarkers for anemia of chronic inflammation) Magnesium and copper adequacy may help restore health. (Food sources were in a recent post: Trace Metals - it's teamwork) Increasing iron intake would not be a solution. Improving the underlying chronic inflammatory condition/s would likely lead to normal hemoglobin production and stop the increased storage of iron. Zinc adequacy may also be important for improving anemia. (Serum Zinc Is a Major Predictor of Anemia and Mediates the Effect of Selenium on Hemoglobin in School-Aged Children in a Nationally Representative Survey in New Zealand) Zinc is essential for immune function. (Zinc and immune function: the biological basis of altered resistance to infection)
Nrf2,a gene and protein involved in our immune function and antioxidant production, is also involved in iron and hemoglobin metabolism.
Some food and menu ideas for increasing phytonutrients in the daily diet that may help the body increase production of Nrf2, : Nrf2 Promoting Foods.
Reference: Trace Metals and Infectious Diseases, Ed. by Jerome O. Nriagu and Eric P. Skaar, (2015, MIT Press, mitpress) pp 210
Disclaimer: Opinions are my own and the information is provided for educational purposes within the guidelines of fair use. While I am a Registered Dietitian this information is not intended to provide individual health guidance. Please see a health professional for individual health care purposes.