Iron Deficiency

By Suzanne Fenske, MD, FACOG, ABOIM, MSCP

Iron Deficiency in Women: Everything You Need to Know About Iron

Iron deficiency is the most common nutrient deficiency in women worldwide, and most of the time, it’s a simple deficiency to correct with dietary changes and supplementation. Yet, women remain underserved in terms of testing and treatment, which can have serious consequences for fertility, pregnancy, and overall health.

Today’s article will discuss everything you need to know about iron, from what it has to do with your periods, who’s at risk, and how to reverse or prevent iron deficiency. Keep reading as we explore:

• What is iron?
• Daily iron requirements
• Iron deficiency and iron deficiency anemia
• Who’s at risk (spoiler: women!)
• How to increase iron intake with food and supplements
• Best practices and how TārāMD can help

What is Iron?

Iron is an essential mineral that you must be obtain in your diet. Its primary function in the body is as a component of hemoglobin, the molecule that carries oxygen in red blood cells and delivers it throughout the body. Iron is also essential for muscle, brain development, growth, cellular function, and hormone production.

Iron absorption is regulated in the small intestine. When iron levels are sufficient, the body absorbs less iron, but when levels are low, absorption increases. Once absorbed, the body is good at holding on to iron. Blood loss, including the menstrual period, is the primary way to lose iron.

How Much Iron Do Women Need?

Adult women need 18mg of dietary iron per day. During pregnancy, especially in the second and third trimesters, this amount increases to 27 mg daily to account for expanded blood volume to support the pregnancy. After menopause, or for women who otherwise don’t have a menstrual cycle, iron requirements drop to 8 mg per day.

What is Iron Deficiency? Iron Deficiency Vs. Iron Deficiency Anemia

Iron deficiency exists on a spectrum where mild iron deficiency involves depleted iron stores (ferritin). Iron deficiency anemia is severe, characterized by low hematocrit and hematocrit levels, indicating insufficient healthy blood cells to transport oxygen.

Ferritin represents iron storage and is the most sensitive marker for iron deficiency. It will deplete first before you see low levels on an iron or CBC (complete blood count) panel.

Deficiencies in vitamin B12 or folate can also cause anemia, but iron deficiency anemia is the most common anemia. Inflammation can also mask anemia, making it harder to diagnose and detect, so it’s important to have proper testing and interpretation from a knowledgeable provider.

Iron deficiency, with or without anemia, may present with the following symptoms:

• Fatigue
• Weakness
• Shortness of breath
• Heart palpitations or arrhythmia
• Hair loss
• Poor appetite
• Brain fog
• Muscle and joint pain
• Weight gain
• Headaches
• Sleep disturbances
• Restless legs
• Depression
• Impaired cognition

Who’s at Risk for Iron Deficiency?

Iron deficiency can result from inadequate iron in the diet, poor iron absorption, or increased iron needs. Let’s look at each case.

Low Iron Intake

Regularly not eating enough iron may result in iron deficiency. Those who follow a vegetarian, vegan, or other plant-based diet may be more at risk. While each dietary pattern may favor certain micronutrients over others, plant-based eaters need to be aware of iron intake. Tracking diet intake and monitoring labs can be helpful for dialing in individual needs.

Poor Iron Absorption

Even when eating enough daily iron, issues with iron absorption may lead to deficiency. For example, celiac disease affects nutrient absorption in the small intestine; iron deficiency is the most common nutrient deficiency in this population. Other gut disorders or infections, such as H. pylori, can also be root causes. Further, bariatric surgery will cause issues with nutrient absorption and often require micronutrient supplementation.

Increased Iron Needs

Heavy periods (menorrhagia) is a primary reason for increased iron needs. It’s possible to lose more iron than you can replace before your next period, and deficiency develops over time. Heavy periods are common with estrogen dominance, endometriosis, uterine fibroids, and perimenopause. Increasing iron intake with food and supplements is helpful, as is understanding and treating the root cause of heavy periods.

Pregnancy is another time in a woman’s life when iron needs increase and when it may be challenging to eat enough iron-rich foods because of nausea and food aversions. For these reasons, pregnant women are more at risk for iron deficiency and require careful monitoring. Some data suggests that globally, iron deficiency or iron deficiency anemia occur in 50% of pregnancies, which can lead to maternal and fetal complications such as preterm delivery and postpartum depression.

Additionally, blood loss from vaginal and cesarean deliveries contributes to iron deficiency, and postpartum women may require more awareness and strategies to rebuild iron stores.

How to Increase Iron Intake with Food

Heme iron comes from animal sources, and nonheme iron from plant sources; both can contribute to overall iron intake, although heme iron is better absorbed and more bioavailable.

Top whole food dietary sources of iron include:

• Oysters and other shellfish
• White beans
• Lentils
• Cooked spinach
• Tofu
• Sardines
• Lean beef
• Chickpeas
• Kidney beans
• Potato with skin
• Cashews

To improve iron absorption from plant sources, such as legumes and leafy greens:

• Pair heme (from meat or seafood) and nonheme iron together
• Pair vitamin C with iron – add lemon juice to greens or tomato sauce to beans
• Cook in a seasoned cast iron skillet
• Separate iron-rich foods from calcium foods (like dairy) and tannins (in coffee and tea), which can inhibit absorption
• Eat a variety of whole, unprocessed foods each day

Iron Supplementation

While it’s possible to meet iron requirements from food alone, if you have heavy periods, are pregnant, or are currently iron deficient, your TārāMD practitioner may recommend supplements to help replete levels and prevent deficiencies.

It’s crucial to test iron levels with a full iron panel and ferritin before supplementation because too much iron can be inflammatory, and you only want to supplement when necessary. For this reason, we often recommend keeping iron supplements separate from your multivitamin or prenatal vitamin. That way you can take your multi daily and add iron only when needed. After menopause, iron supplementation typically isn’t recommended.

Some ideas for supplementation:

• Choose iron bisglycinate, which is well absorbed and tends to be better tolerated by those with sensitive stomachs.
• Supplement every other day instead of daily. Research suggests this method improves iron absorption.
• Monitor levels and adjust as you go.
• Keep focusing on iron-rich foods.

Iron is a micronutrient to consider if you feel tired, slow, and foggy. Of course, iron deficiency isn’t the only possible cause for these symptoms. At TārāMD, we take a comprehensive view of your health picture to determine the specific imbalances. When iron deficiency or anemia is part of the picture, we’ll tailor nutrition and supplement strategies to improve your levels and how you feel.

Further, and importantly, we’ll ask the question why. Why are iron levels low? Is it because of heavy periods, a gut issue, or not eating enough in the first place? With this understanding, we can treat the root cause and prevent iron deficiency down the road.

References

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