A Functional Medicine Guide To Iron Deficiency

A Functional Medicine Guide To Iron Deficiency Dr. Will Cole

As a functional medicine practitioner, I talk to my patients about nutrient deficiencies all the time. After all, at the root of my health philosophy is the idea that the right food can improve virtually all health issues. With many of my patients, correcting a nutrient deficiency is a big piece of the puzzle of improving their health - especially when it comes to reducing symptoms like headaches, fatigue, and a weakened immune system. And one deficiency that I see all too frequently is iron deficiency. 

Unfortunately, unlike B12 or vitamin D, iron deficiency doesn’t get a lot of attention in the wellness scene. But the truth is, iron deficiencies are the most common deficiency in the world! In fact, according to the Centers for Disease Control, about 10 percent of women are iron deficient. (1) And that's why in this blog, I’ll be diving into iron deficiencies, why they occur, and most importantly, how you can correct a deficiency by eating the right foods.


Make Your Life a Cleanse



Get FREE access to these + giveaways, recipes, & discount codes in personal emails from Dr. Will Cole.

What is an iron deficiency? 

Iron is a mineral that’s found on earth and in certain foods. Our bodies don’t make iron, so we have to get it through the foods we eat. Like the name suggests, an iron deficiency occurs when your body doesn’t have enough iron through our diet. This is a problem for many reasons but the most important is the fact that iron is required to make hemoglobin — an important protein in red blood cells that helps carry oxygen around the body. When iron deficiency is left unchecked, it can lead to iron-deficiency anemia. 

As we already learned, iron-deficiency anemia is very common, mostly because the standard American diet is low in essential nutrients, including iron. Iron deficiency anemia can also occur because of blood loss — either from an injury or menstruation — or an inability to absorb iron from the food you do eat because of inflammatory bowel disease or a restrictive diet. Your iron requirements also increase when you’re pregnant, so pregnant women or new mothers can sometimes become deficient. 

What are the symptoms of iron deficiency? 

Iron deficiency can lead to a wide range of symptoms that often get misdiagnosed or missed by conventional medicine doctors. That’s because iron doesn’t just help carry oxygen to cells, it also plays a role in various enzymatic reactions in the body that govern muscle metabolism, physical growth, neurological development, and even the synthesis of different hormones. (2

In other words, iron is a pretty big deal. 

So how do you know if you have an iron deficiency? According to Mayo Clinic, the typical symptoms of an iron deficiency include (3): 

  • Extreme fatigue
  • Weakness
  • Pale skin
  • Chest pain, fast heartbeat or shortness of breath
  • Headache, dizziness or lightheadedness
  • Cold hands and feet
  • Inflammation or soreness of your tongue
  • Brittle nails
  • Unusual cravings for non-nutritive substances, such as ice, dirt, or starch
  • Poor appetite, especially in infants and children with iron deficiency anemia

These symptoms are often missed because they are vague and can also be attributed to other deficiencies or health issues, like low thyroid or chronic fatigue syndrome. I often uncover iron deficiencies in patients that have seen multiple doctors without much luck getting to the root cause of their health issues. 

How do you diagnose an iron deficiency? 

Diagnosing an iron deficiency is typically a multistep process. First, I will perform a physical exam and ask my patients about their medical history and current symptoms. When it comes to diagnostic tests, I will often order: 

  • A complete blood count (CBC): This would tell us your red blood cell count and your hemoglobin levels. If either are low, you may be anemic. 
  • Iron blood test: This test would tell us how much iron is in your blood but it is not foolproof because even if this test is normal, the amount of iron in the rest of your body may be low. 
  • Ferritin test: Ferritin is a protein that helps store iron in your body. If it’s low, it’s a sign that your body’s iron may also be low. 
  • Reticulocyte count: Reticulocytes are young red blood cells and if your levels are low, it’s a good sign that iron is also low. 
  • Peripheral smear: This test looks at your red blood cells under a microscope to see if they are smaller or paler than they should be. If they are, that’s a sign that iron is low! 

Typically, a diagnosis is made when more than one test indicates a deficiency. 

How do you correct an iron deficiency? 

The bad news is that iron deficiency is pretty common; the good news is that it’s also pretty easy to fix! First, I recommend that my patients eat more iron-rich foods, (4) including: 

  • Lean beef
  • Oysters
  • Chicken
  • Turkey
  • Beans and lentils
  • Tofu
  • Baked potatoes
  • Cashews
  • Dark green leafy vegetables such as spinach
  • Fortified breakfast cereals
  • Whole-grain and enriched breads

If you’re low in iron, it’s important to also eat plenty of vitamin C-rich foods because vitamin C enhances the absorption of iron. (3) Vitamin C is found in: 

  • Broccoli
  • Grapefruit
  • Kiwi
  • Leafy greens
  • Melons
  • Oranges
  • Peppers
  • Strawberries
  • Tangerines

If increasing your intake of vitamin C and iron-rich foods doesn’t improve your iron levels, you can talk to your doctor about taking an iron supplement. (I don’t recommend supplementing with iron unless you are working with a professional since taking them when you don’t need them can be dangerous.) 

Iron is an often overlooked but extremely important mineral! It would benefit us all to make sure we're eating iron-rich foods, getting our daily dose of vitamin C, and having our iron levels checked if we're experiencing any of the symptoms of an iron deficiency above. The good news is that once they’re caught, iron deficiencies are an easy fix!

As one of the first functional medicine telehealth clinics in the world, we provide webcam health consultations for people around the globe. 

Photo: unsplash.com

Start Your Health Journey Today



  1. Recommendations to Prevent and Control Iron Deficiency in the  United States. https://www.cdc.gov/mmwr/preview/mmwrhtml/00051880.htm. Accessed November 18, 2020.
  2. Office of Dietary Supplements - Iron. https://ods.od.nih.gov/factsheets/Iron-HealthProfessional/. Accessed November 18, 2020.
  3. Iron deficiency anemia - Symptoms and causes - Mayo Clinic. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/iron-deficiency-anemia/symptoms-causes/syc-20355034#:~:text=As%20the%20name%20implies%2C%20iron,tired%20and%20short%20of%20breath. Published October 18, 2019. Accessed November 18, 2020.
  4. Foods to Fight Iron Deficiency. https://www.eatright.org/health/wellness/preventing-illness/iron-deficiency. Accessed November 18, 2020.

View More At Our Store

Purchase personally curated supplements
and Dr. Will Cole’s books!

Bew Global Shop Banner

The information on this website has not been evaluated by the Food & Drug Administration or any other medical body. We do not aim to diagnose, treat, cure or prevent any illness or disease. Information is shared for educational purposes only. You must consult your doctor before acting on any content on this website, especially if you are pregnant, nursing, taking medication, or have a medical condition.

Our content may include products that have been independently chosen and recommended by Dr. Will Cole and our editors. If you purchase something mentioned in this article, we may earn a small commission.



Evidence-based reviewed article

Dr. Will Cole, DNM, IFMCP, DC is a leading functional medicine expert who consults people around the globe, starting one of the first functional medicine telehealth centers in the world. Named one of the top 50 functional and integrative doctors in the nation, Dr. Will Cole provides a functional medicine approach for thyroid issues, autoimmune conditions, hormonal imbalances, digestive disorders, and brain problems. He is the host of the popular The Art Of Being Well podcast and the New York Times bestselling author of Intuitive Fasting, Ketotarian, The Inflammation Spectrum and the brand new book Gut Feelings: Healing the Shame-Fueled Relationship Between What You Eat and How You Feel.

Gut Feelings Dr. Will Cole 6

Gut Feelings

Healing The Shame-Fueled Relationship
Between What You Eat And How You Feel