Iron Deficiency Reaches Beyond Anemia: Why Low Ferritin Deserves Attention Even at Mild Levels

Dr Rakesh Gupta, a senior consultant in internal medicine at Indraprastha Apollo Hospitals, has a plain answer to a question many people with a borderline blood report ask: should low ferritin alongside mild anemia be a worry? Yes, he says, even when symptoms seem minor. The Financial Express published his answers on September 6, 2025, in a question-and-answer piece on iron deficiency and what it does beyond anemia.

The starting point is ferritin, which Gupta describes as a key indicator of the body's iron stores. Low levels, he explains, often mark the early stage of iron deficiency. Mild anemia may produce no obvious symptoms, but he says it can gradually wear down energy, cognitive function, immune response and physical endurance. Left untreated, persistent low ferritin can progress to more severe anemia, which may call for more aggressive treatment such as intravenous iron.

There is a second reason not to wave it off. Low ferritin can point to something underneath, such as chronic blood loss from heavy menstruation or gastrointestinal problems, or a problem absorbing iron. Catching it early, Gupta says, keeps treatment simple: dietary changes or oral supplements. He singles out women of childbearing age, athletes, vegetarians and people with chronic conditions as groups for whom regular monitoring matters most. The article frames iron deficiency as the most common nutritional deficiency, especially among women.

Asked about long-term effects, Gupta begins with the mechanism. Iron is needed to make hemoglobin, the molecule in red blood cells that carries oxygen. When iron runs short, tissues get less oxygen, and the result can be persistent fatigue, weakness, dizziness and trouble thinking clearly. In children, he says, deficiency can stunt growth and impair brain development. Adults may find their exercise capacity drops, concentration suffers and infections come more easily because immune function is weakened.

He adds that in women, low iron can worsen menstrual problems and fertility difficulties. The heart may also be affected, since it works harder to compensate for lower oxygen levels, which can stress the cardiovascular system. Other signs he lists include brittle nails, hair loss, restless leg syndrome and intolerance to cold. His overall point is that untreated low iron can quietly erode quality of life, and that vague or mild symptoms are no reason to delay finding it.

The next question is the one that puzzles many people: why would someone who looks healthy and eats well still run low? Gupta offers several explanations. Absorption differs between individuals and can be impaired by celiac disease, inflammatory bowel disease or gastric surgery. Small, often unnoticed blood loss can drain stores over time, from heavy periods, bleeding hemorrhoids or gastrointestinal ulcers. Medications such as NSAIDs, ibuprofen among them, may contribute to gastrointestinal bleeding over time.

Diet matters too, though not only in the sense of how much iron is eaten. Vegetarians, and people whose diets are high in fiber or tea, may absorb less iron because of inhibitors such as phytates and tannins. Chronic illnesses, including kidney disease, cancer and inflammation from autoimmune conditions, can disrupt iron metabolism. Even regular endurance exercise can raise iron loss through sweat, urine and minor gastrointestinal bleeding. A healthy lifestyle, Gupta concludes, does not rule out low iron.

The piece closes on a third question, about which warning signs to watch for given that most people never test their iron levels, but the published text breaks off before an answer. What it does establish is the practical takeaway: fatigue, poor concentration or the other nonspecific symptoms above are worth a ferritin check, particularly for the groups Gupta names.