Iron Deficiency in Women: Why It's Often Missed and How to Test

Iron deficiency is the most common nutritional deficiency worldwide, and women are disproportionately affected. Yet it's frequently overlooked, dismissed, or inadequately tested. Understanding the full picture of iron testing can help you advocate for yourself and get the answers you need.

Why Women Are at Higher Risk

Women have unique risk factors for iron deficiency:

• Menstruation: Monthly blood loss depletes iron stores
• Heavy periods: Can cause significant iron loss
• Pregnancy: Iron needs increase dramatically
• Breastfeeding: Continued higher iron demands
• Vegetarian/vegan diets: Plant iron is less easily absorbed
• Athletic training: Exercise increases iron needs

Symptoms of Iron Deficiency

Iron deficiency symptoms are often vague and easily attributed to other causes:

• Fatigue and weakness
• Difficulty concentrating ("brain fog")
• Shortness of breath with activity
• Pale skin, lips, or nail beds
• Cold hands and feet
• Brittle nails or hair loss
• Headaches or dizziness
• Restless leg syndrome
• Cravings for ice or non-food items (pica)
• Increased susceptibility to infections

The Complete Iron Panel

A hemoglobin test alone isn't enough. Here's what a complete iron assessment includes:

Ferritin

The most important marker for iron stores.

• What it measures: Iron stored in your body
• Lab "normal" range: Often 12-150 ng/mL
• Optimal range: 50-150 ng/mL
• For symptom relief: Most women feel best above 50 ng/mL
• Important note: Ferritin rises with inflammation, so it may appear falsely normal during illness

Serum Iron

The amount of iron circulating in your blood.

• Can fluctuate throughout the day
• Affected by recent meals
• Best tested fasting in the morning

TIBC (Total Iron Binding Capacity)

Measures how much iron your blood could carry.

• High TIBC suggests iron deficiency (your body is trying to grab more iron)
• Low TIBC may indicate iron overload or chronic disease

Transferrin Saturation

Calculated from iron and TIBC; shows how much of your iron-carrying capacity is being used.

• Low percentage (<20%) suggests iron deficiency
• Very high percentage (>45%) may indicate iron overload

Hemoglobin and Hematocrit (CBC)

Part of a Complete Blood Count; becomes abnormal only when deficiency progresses to anemia.

• Hemoglobin <12 g/dL in women indicates anemia
• MCV (mean cell volume) is low in iron deficiency anemia

Stages of Iron Deficiency

Stage 1: Iron Depletion

Ferritin drops but serum iron and hemoglobin remain normal. You may have no symptoms or mild fatigue.

Stage 2: Iron Deficiency

Iron stores are exhausted, transferrin saturation drops. Symptoms like fatigue and brain fog appear, but hemoglobin is still normal.

Stage 3: Iron Deficiency Anemia

Hemoglobin drops below normal. Symptoms are more pronounced. This is the only stage detected by standard screening.

Why Standard Testing Misses It

Many providers only check hemoglobin or CBC, which only catches Stage 3 (anemia). By then, you've been symptomatic for months or years.

Additionally:

• Lab "normal" ranges for ferritin are often too wide (some labs list 12 ng/mL as normal)
• Symptoms are dismissed as stress, depression, or "being a busy woman"
• Iron studies may not be ordered unless anemia is already present

Factors That Affect Iron Absorption

Enhance Absorption:

• Vitamin C (eat citrus with iron-rich foods)
• Meat, fish, poultry (contain "heme" iron and enhance non-heme absorption)
• Cooking in cast iron

Inhibit Absorption:

• Coffee and tea (wait 1-2 hours after meals)
• Calcium supplements (take at different times)
• High-fiber foods (when taken with iron)
• Antacids and PPIs (reduce stomach acid needed for absorption)

When to Get Tested

Consider iron testing if you:

• Have unexplained fatigue
• Have heavy periods
• Are pregnant or planning pregnancy
• Follow a vegetarian or vegan diet
• Are an endurance athlete
• Have a history of GI issues or celiac disease
• Previously had low iron or anemia