Iron Deficiency in Women: Why It's So Common and What to Do About It

Iron deficiency is the most common nutritional deficiency worldwide, and women of reproductive age are disproportionately affected. Yet it's routinely overlooked — symptoms are attributed to stress, aging, or "just being tired," and standard blood work often misses it entirely.

If you've been exhausted despite adequate sleep, can't think clearly, feel short of breath climbing stairs, or notice your hair thinning — iron deficiency belongs on the list of things to check.

Why Women Are Especially Vulnerable

The math is straightforward. Women lose iron through menstruation every month. The average period results in about 30-40 mL of blood loss per cycle — more if periods are heavy. Each milliliter of blood contains about 0.5 mg of iron. Meanwhile, dietary iron absorption is limited (typically 1-2 mg per day from a normal diet).

Heavy periods (menorrhagia) dramatically increase the risk. If you regularly soak through pads or tampons hourly, pass clots, or bleed for more than seven days, your iron losses may far exceed what diet alone can replace.

Other risk factors in women include:

• Pregnancy — iron needs roughly double during pregnancy to support increased blood volume and fetal development
• Breastfeeding — continued iron demands postpartum
• Vegetarian or vegan diets — plant-based (non-heme) iron is absorbed less efficiently than animal-based (heme) iron
• Frequent blood donation
• GI conditions affecting absorption (celiac disease, inflammatory bowel disease, gastric bypass surgery)

Symptoms of Iron Deficiency

Iron deficiency exists on a spectrum. You can be iron-depleted (low stores) without being anemic (low hemoglobin), and you can have significant symptoms at either stage.

Fatigue and weakness

The hallmark symptom. Iron is essential for hemoglobin, which carries oxygen to every cell in your body. Less iron means less oxygen delivery, which means less energy production. This isn't the kind of tired that a good night's sleep fixes.

Brain fog and poor concentration

Iron is also critical for brain function — neurotransmitter synthesis, myelination, and energy metabolism in the brain all depend on adequate iron. Cognitive symptoms can appear before anemia does.

Shortness of breath with exertion

Activities that used to be effortless — climbing stairs, walking uphill, carrying groceries — leave you winded. Your body is compensating for reduced oxygen-carrying capacity.

Hair loss

Iron deficiency is one of the most common reversible causes of hair thinning in women. Hair follicles are among the most rapidly dividing cells in the body and are sensitive to iron status.

Pale skin and pale inner eyelids

Hemoglobin gives blood its red color. With less hemoglobin, skin (particularly in lighter-skinned individuals) and mucous membranes appear paler.

Restless legs

An uncomfortable urge to move your legs, particularly at rest or at night. Iron deficiency is one of the most well-established causes of restless legs syndrome.

Cold hands and feet

Impaired oxygen delivery affects circulation and temperature regulation.

Brittle nails, cracked lips, mouth sores

These are signs of more advanced deficiency.

Pica — cravings for non-food items like ice, dirt, or starch — is a classic but underrecognized sign.

Testing: Don't Just Check Hemoglobin

This is where things often go wrong. A standard CBC (complete blood count) checks hemoglobin, but hemoglobin is the last thing to drop in iron deficiency. You can have significantly depleted iron stores and a normal hemoglobin.

The test you need is ferritin — it reflects your body's iron stores. A ferritin below 30 ng/mL is consistent with iron depletion, even if your hemoglobin is normal. Many labs list the "normal" range as 10-150 or similar, but symptoms often appear well above the lower cutoff.

A complete iron panel includes:

• Ferritin (iron stores)
• Serum iron (circulating iron)
• TIBC (total iron-binding capacity — elevated when iron is low)
• Transferrin saturation (percentage of transferrin carrying iron)

If your doctor checks only hemoglobin and tells you you're fine, but your ferritin is 12 — you're not fine.

Treatment

Oral iron supplementation

The first-line treatment for most cases. Ferrous sulfate, ferrous gluconate, and ferrous bisglycinate are common forms. Ferrous bisglycinate tends to be better tolerated with fewer GI side effects (constipation, nausea, stomach upset).

Tips for better absorption:

• Take on an empty stomach if tolerated (or with a small amount of food if needed)
• Take with vitamin C (orange juice, a vitamin C supplement) — this significantly increases absorption
• Avoid taking with calcium, coffee, or tea, which inhibit absorption
• Every-other-day dosing may actually be more effective than daily dosing (counterintuitive but supported by research)

IV iron

For women who can't tolerate oral iron, have absorption issues, have very low levels, or need faster repletion (such as during pregnancy or before surgery), IV iron infusion is highly effective. Modern IV iron formulations are safe and well-tolerated.

Address the underlying cause

Supplementing iron while ignoring the reason for deficiency is like bailing water without plugging the hole. Heavy periods should be evaluated and treated. GI causes of blood loss or malabsorption need investigation.

How Long Until You Feel Better?

Most women notice improved energy within 2-4 weeks of starting iron supplementation. Full repletion of iron stores typically takes 3-6 months. It's important to continue supplementation even after feeling better — replenishing stores takes longer than resolving symptoms.

Ready to talk to a real doctor? Get started with Coral Health today.