Iron deficiency is the most common nutritional deficiency worldwide — affecting roughly 2 billion people globally. Yet it's frequently missed or undertreated in conventional care. Understanding iron's role in the body, who's at risk, and how to identify and address deficiency is essential knowledge for anyone invested in their health.
Why Iron Matters
Iron is essential for hemoglobin — the protein in red blood cells that carries oxygen from the lungs to every cell in the body. It's also required for myoglobin (oxygen storage in muscles), energy production in mitochondria, immune function, thyroid hormone synthesis, and neurotransmitter production including dopamine and serotonin.
Symptoms of Iron Deficiency
Iron deficiency exists on a spectrum from early depletion to frank anemia. Symptoms include fatigue and weakness, brain fog and poor concentration, cold hands and feet, hair loss, brittle nails, pale skin and inner eyelids, shortness of breath with exertion, restless leg syndrome, and frequent infections. Importantly, these symptoms can occur even before anemia develops — when iron stores are low but hemoglobin is still 'normal.'
Who Is Most at Risk?
- Menstruating women: Monthly blood loss increases iron requirements significantly.
- Pregnant women: Iron demands increase dramatically to support fetal development.
- Infants and young children: Rapid growth creates high iron requirements.
- Vegetarians and vegans: Non-heme iron from plants is less bioavailable than heme iron from animal sources.
- Endurance athletes: High foot-strike hemolysis and sweat losses increase iron turnover.
- People with gut inflammation: Celiac disease, IBD, and other gut conditions impair iron absorption.
Testing for Iron Status
A complete iron assessment includes ferritin (iron stores), serum iron, TIBC (total iron binding capacity), and transferrin saturation — in addition to the standard CBC that assesses hemoglobin. Ferritin below 30 ng/mL is associated with symptoms even without anemia, and optimal ferritin is typically 50-100 ng/mL for most people.
Addressing Iron Deficiency
Iron bisglycinate is the most well-tolerated oral form — significantly less constipating than ferrous sulfate. Take with vitamin C and away from coffee, tea, and calcium. For severe deficiency or malabsorption, IV iron may be appropriate. Always identify the cause of deficiency — ongoing blood loss or malabsorption must be addressed alongside supplementation.
