Low Ferritin? What This Biomarker Means For Your Hormone Health, Energy Levels + More


There are many terms in the world of health and wellness that, while important to understand, can be incredibly confusing if you aren’t given the proper information. One of these terms I see often causing such confusion is ferritin. You may know that it has something to do with iron, a necessary nutrient needed for optimal health, but the understanding stops there. 

As a functional medicine expert, I believe that knowledge is power and the more you know about your health, the more empowered you will be to take the appropriate action steps necessary to reclaim the vibrant health you deserve. So instead of gatekeeping my knowledge or sending you down a never-ending search engine rabbit hole to figure it out yourself, read on for everything you need to know about ferritin and what this biomarker can reveal about your health.


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What is ferritin?

There is a lot of confusion when it comes to ferritin due to its relationship with iron. Are iron and ferritin the same; are they just interchangeable terms for the same thing? It can be pretty confusing, so let’s break it down. First things first, it’s true that you can’t talk about iron without talking about ferritin, but they are not one in the same.

Ferritin is a protein that acts as a storage system for iron within the body. If it’s low, it’s a sign that your body’s iron levels may also be low. Iron is an essential mineral that is crucial for a variety of physiological processes, including oxygen transport, DNA synthesis, and cellular metabolism. 

Despite its importance, excessive or insufficient levels of iron can be detrimental to health. Ferritin serves as a buffer to prevent iron from reaching toxic levels and at the same time protecting you against iron deficiency by moderating its use. For example, when your body requires iron for critical functions such as hemoglobin production (essential for oxygen transport in red blood cells), ferritin launches a controlled release of your body’s stored iron to ensure a steady and regulated supply of this vital mineral. Ferritin is your body’s very own goldilocks principle come to life - not too much, and not too little.

How does ferritin affect your health?

Beyond its role in iron storage, research has found that ferritin also influences multiple areas of your health that can lead to a cascade of chronic health problems if left unaddressed.

1. Ferritin + energy levels

Energy production within your body heavily relies on adequate oxygen supply facilitated by iron. Low ferritin levels often correlate with reduced oxygen-carrying capacity in the blood, leading to fatigue, weakness, and diminished energy levels. If you have low ferritin levels, you are likely to experience chronic fatigue and symptoms of anemia including shortness of breath and dizziness.

2. Ferritin + hormone health

The intricate connection between ferritin and your hormones doesn’t always get the attention it deserves in mainstream medicine, and since your hormones play a crucial role in regulating everything from your metabolism, mood, and reproductive health, imbalances can lead to a cascade of chronic health problems.

Multiple studies have found a link between low ferritin levels and iron deficiency and poor thyroid hormone metabolism, with one study (1) in particular showing a link between low ferritin and iron deficiency and the development of hypothyroidism - a condition where your thyroid doesn’t produce enough thyroid hormones - that can lead to weight gain, hair loss, chronic fatigue, and more. Additional studies, one recently published in the journal Frontiers in Endocrinology, (2) found a shocking connection between unexplained fertility and iron deficiency. In fact, all of the women in the study had ferritin levels <30µg/L as well as abnormal thyroid antibodies - further showing ferritin’s role in thyroid hormone health.

3. Ferritin + immune health

Ferritin plays an important role in your immune health, as its levels rise (3) as part of your body's defense mechanism against infections and modulating immune responses. Ferritin is often referred to as an acute phase reactant since your ferritin levels rise in response to inflammation. That’s why people with chronic health problems can have high ferritin levels. If a blood test indicates that your ferritin levels are high, it’s a good indicator to myself and other doctors that chronic inflammation and potentially more serious health problems are at play.

4. Ferritin + mood regulation

Iron is a crucial component in various neurological processes, including neurotransmitter synthesis, myelination, and energy metabolism within the brain. Ferritin's role in maintaining optimal iron levels is essential for cognitive health, as iron deficiency can detrimentally impact cognitive function, especially when it comes to your mood. For example, in order for your brain to produce dopamine it needs iron. Studies have shown that iron deficiency is higher (4) in people with depression and anxiety and can impact (5) neurotransmitter function. Other research (6) has found that the slightest change in ferritin levels - even before anemia occurs - can result in higher incidences of depression.

What causes low ferritin levels?

There are many things that can lead to low ferritin levels, including:

  • Poor diet: Low intake of iron-rich foods, like red meat, poultry, fish, legumes, nuts, and dark green leafy vegetables, can lead to low ferritin levels over time.
  • Blood loss: Chronic or temporary blood loss, such as heavy menstrual bleeding can deplete iron stores and lead to low ferritin levels.
  • Gut problems: Celiac disease, inflammatory bowel disease like Crohn's or ulcerative colitis can impair your gut’s ability to absorb iron from your diet, resulting in decreased ferritin levels.
  • Certain health problems: Chronic inflammatory conditions like rheumatoid arthritis, chronic kidney disease, or certain infections can lead to increased levels of hepcidin, (7) a hormone that inhibits iron absorption, consequently lowering ferritin levels.

In my telehealth functional medicine clinic, low ferritin levels act as an indicator for us to dive deeper into your health case as this is usually a sign that there is something bigger going on beneath the surface that needs to be addressed.

How to test your ferritin levels and optimization strategies

You can look at both ferritin and iron levels through a simple blood test. In conventional medicine, (8) your iron levels should be 10-30 umol/L and your ferritin should be between 40-300 ug/L for men and between 20-200 ug/L for women. 

According to the National Institutes of Health, (9) you should be getting this much iron per day in order to maintain optimal iron levels.

  • Birth to 6 months: 0.27 mg
  • Infants 7–12 months: 11 mg
  • Children 1–3 years: 7 mg
  • Children 4–8 years: 10 mg
  • Children 9–13 years: 8 mg
  • Teen boys 14–18 years: 11 mg
  • Teen girls 14–18 years: 15 mg
  • Adult men 19–50 years: 8 mg
  • Adult women 19–50 years: 18 mg
  • Adults 51 years and older: 8 mg
  • Pregnant women: 27 mg
  • Breastfeeding women: 9 mg

Once you know where you stand, your doctor can help you come up with a plan of action if you are trending toward an iron deficiency. Some of these strategies include:

1. Eat more iron-rich foods

Not only will food help you overcome deficiencies and bulk up your iron stores, eating an iron-rich diet will help you maintain your levels long-term. While there are many foods fortified and enriched with iron, they are highly processed and not ideal. Some of the highest clean food sources of iron include:

  • Lean beef
  • Oysters
  • Chicken
  • Turkey
  • Beans and lentils
  • Tofu
  • Baked potatoes
  • Cashews
  • Dark green leafy vegetables such as spinach

2. Eat more Vitamin C-rich foods

The beauty of our biochemistry is that certain nutrients enhance absorption of one another when taken together. Vitamin C is known to enhance absorption of iron, so take advantage of vitamin synergy and make a meal consisting of some of the iron-rich foods above and these Vitamin-C rich foods below:

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

3. Take iron supplements

While I believe that food is foundational for sustainable change, iron supplements can be beneficial in cases of severe deficiency, to boost ferritin levels. Once you have tested your ferritin and iron levels, your doctor can work with you to determine the right dosage for your needs.

4. Medical interventions

In some cases, deficiency is not the issue, it's an overabundance of iron that can lead to problems. Hemochromatosis is one condition where your body stores up too much iron in your skin, liver, pancreas, and other organs resulting in toxicity and further complications like cirrhosis of the liver. Unfortunately, most people don’t know they have this condition until iron levels have reached toxic levels for a prolonged period of time and the damage has already occurred. 

However, since this is a genetically inherited condition, testing can be done to determine if this is a possible factor in your health case before symptoms arise. If you catch it early enough, treatment can be as simple as regular ferritin and iron testing along with scheduled blood draws (10) to eliminate the excess iron from your body.

For a complete guide to iron and how to correct a deficiency, check out my article here.

The Takeaway

Ultimately, ferritin is a biomarker that reveals a lot about your overall health. By cluing you into deeper health problems and helping you connect the dots between your symptoms, ferritin is an important piece of your health puzzle that shouldn’t be ignored. In my telehealth functional medicine clinic, run ferritin tests as part of our comprehensive lab work in order to get a complete picture of your health case. If you want to learn more about testing and how we can help you in your journey to better health with functional medicine, schedule a telehealth consultation today.

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

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  1. Maldonado-Araque, Cristina et al. “Iron deficiency is associated with Hypothyroxinemia and Hypotriiodothyroninemia in the Spanish general adult population: Di@bet.es study.” Scientific reports vol. 8,1 6571. 26 Apr. 2018, doi:10.1038/s41598-018-24352-9
  2. Holzer, Iris et al. “Iron status in women with infertility and controls: a case-control study.” Frontiers in endocrinology vol. 14 1173100. 8 Jun. 2023, doi:10.3389/fendo.2023.1173100
  3. Kernan, Kate F, and Joseph A Carcillo. “Hyperferritinemia and inflammation.” International immunology vol. 29,9 (2017): 401-409. doi:10.1093/intimm/dxx031
  4. Lee, HS., Chao, HH., Huang, WT. et al. Psychiatric disorders risk in patients with iron deficiency anemia and association with iron supplementation medications: a nationwide database analysis. BMC Psychiatry 20, 216 (2020). https://doi.org/10.1186/s12888-020-02621-0
  5. Kim, Jonghan, and Marianne Wessling-Resnick. “Iron and mechanisms of emotional behavior.” The Journal of nutritional biochemistry vol. 25,11 (2014): 1101-1107. doi:10.1016/j.jnutbio.2014.07.003
  6. Vahdat Shariatpanaahi, M et al. “The relationship between depression and serum ferritin level.” European journal of clinical nutrition vol. 61,4 (2007): 532-5. doi:10.1038/sj.ejcn.1602542
  7. D'Angelo, Guido. “Role of hepcidin in the pathophysiology and diagnosis of anemia.” Blood research vol. 48,1 (2013): 10-5. doi:10.5045/br.2013.48.1.10
  8. National Heart, Lung, and Blood Institute “Iron-Deficiency Anemia” Accessed December 2023. https://www.nhlbi.nih.gov/health/anemia/iron-deficiency-anemia
  9. National Institutes of Health “Iron” Accessed December 2023. https://ods.od.nih.gov/factsheets/Iron-Consumer/
  10. National Institute of Diabetes and Digestive and Kidney Diseases “Hemochromatosis” Accessed December 2023. https://www.niddk.nih.gov/health-information/liver-disease/hemochromatosis 

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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.

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