Iron: The Nutrient Women Are Most Likely to Miss

Iron deficiency is the most common nutrient deficiency in the world, and women carry most of the burden. An estimated one in three women of reproductive age has low iron, yet many never realize it — the symptoms creep in slowly and are easy to blame on a busy life. Here's why iron matters so much for women, how to spot the warning signs, and what to do about it.

Why Women Run Low on Iron

Your body loses iron every time you bleed, and menstruation is the single biggest reason women need almost twice as much iron as men — 18 mg per day versus 8 mg. Women with heavy periods lose even more, and each pregnancy draws heavily on iron stores to support the baby and the 50% increase in blood volume.

Diet plays a role too. Plant-based eating has many benefits, but the iron in plants (non-heme iron) is absorbed far less efficiently than the iron in meat. Women who eat little or no red meat — vegetarians, vegans, or simply light meat-eaters — need to be more deliberate about their iron intake. Frequent intense exercise, regular blood donation, and gut conditions that impair absorption can also tip the balance.

The Symptoms Everyone Dismisses

Iron deficiency rarely announces itself dramatically. Instead, it shows up as:

• Persistent fatigue — Tiredness that sleep doesn't fix, because your blood is carrying less oxygen to your muscles and brain.
• Hair shedding — Hair follicles are highly sensitive to iron levels. Increased shedding is a classic early sign.
• Brain fog — Trouble concentrating, forgetfulness, and low mood. Iron is essential for neurotransmitter production.
• Other clues — Pale skin, brittle nails, breathlessness on stairs, cold hands and feet, restless legs at night, and unusual cravings for ice.

Heme vs. Non-Heme: Not All Iron Is Equal

Food contains two types of iron. Heme iron, found in animal foods, is absorbed at around 15–35%. Non-heme iron, found in plants, is absorbed at only 2–20%, and its absorption is easily blocked by other compounds in your meal.

• Best heme sources — Lean beef, lamb, pork, chicken thigh, sardines, oysters, and mussels.
• Best non-heme sources — Lentils, chickpeas, tofu, tempeh, spinach, pumpkin seeds, quinoa, and iron-fortified cereals.
• The vitamin C trick — Pairing non-heme iron with vitamin C (citrus, bell peppers, strawberries, tomatoes) can multiply absorption several times over. A squeeze of lemon on your lentils genuinely helps.
• What blocks absorption — Tea, coffee, and calcium supplements taken with meals all inhibit iron uptake. Enjoy them between meals instead.

When to Test Your Ferritin

Ferritin is a measure of your body's stored iron, and it drops long before full-blown anemia develops. A standard hemoglobin test can look "normal" while your iron stores are nearly empty — which is why many women are told everything is fine when it isn't.

Consider asking your doctor for a ferritin test if you have heavy periods, follow a plant-based diet, are pregnant or planning pregnancy, are a frequent blood donor, or simply have unexplained fatigue, hair loss, or brain fog. If your ferritin is low, your doctor can help you decide between dietary changes and supplementation, and investigate the underlying cause.

Fatigue is not just part of being a busy woman. If you've been running on empty for months, get your iron checked — it's one of the most fixable causes of feeling unwell.

The Bottom Line

Iron quietly powers your energy, your focus, and even your hair. Because women lose iron every month, deficiency is common — but it's also easy to detect and treat. Eat iron-rich foods regularly, pair plant sources with vitamin C, keep tea and coffee away from mealtimes, and don't hesitate to ask for a ferritin test if something feels off.