Iron is the clearest example of a marker where the female body works under a constraint the reference ranges were not built around. Losing blood every month is a monthly iron cost, and it has to be paid back through food.
Why women are more exposed
Repeated menstrual blood loss represents a regular iron cost the body has to compensate for through diet. Heavy periods (menorrhagia) raise that risk substantially, as do pregnancy, breastfeeding, and a diet low in bioavailable iron — vegetarian or vegan eating without particular attention to this one nutrient.
The symptoms that should prompt a check
Persistent fatigue, unusual breathlessness on exertion, pallor, diffuse hair loss, brittle or spoon-shaped nails. Taken together these point towards iron deficiency even with no frank anaemia in the strict sense. Low ferritin without declared anaemia remains under-diagnosed, although it often carries the same symptoms — the stores are empty before the blood count says so.
How to correct a deficiency
Food comes first: red meat, pulses and green vegetables, paired with vitamin C, which is the one food component reliably shown to improve absorption of non-haem (plant) iron. Tea and coffee work the other way: drunk with an iron-rich meal their polyphenols cut absorption of plant iron sharply, though the effect fades within about an hour, so spacing them from the meal is enough. Where a deficiency is confirmed, supplementation may be proposed, but it should stay medically supervised: excess iron is not harmless, and supplementing without a proven deficiency is not recommended. Refilling the stores takes months, not weeks.
- Pair plant sources of iron with something rich in vitamin C to improve absorption.
- Keep tea and coffee away from iron-rich meals — they cut absorption significantly.
- Do not supplement without a confirmed deficiency — an excess is not harmless.
- If your periods are heavy, raise it specifically in consultation — it is a risk factor in its own right.
Reviewed by the OVEA medical committee