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  • Writer's pictureDr. Randi Brown, ND

Fatigued? What's Ferritin Got To Do With It?

Updated: Nov 25, 2023

What do you do when you feel low energy, yet on paper, you seem to appear perfectly healthy?

I get this all the time with patients in my practice. They are frustrated, or in complete disbelief that they appear "fine", despite not feeling fine.

What Is Ferritin? Why Does It Matter?

Ferritin (a blood marker), maybe one of the most important, yet controversial lab tests that doctors run if their patients are concerned about their low energy levels. Often when patients bring in their previous labs they will say something like "I did all this blood work, but my doctor said it was fine and so we didn't do anything". Meanwhile, they are extremely lethargic, despite sleeping nearly too much, have pale skin, shortness of breath, and experience restless legs at night. After looking at their labs, particularly their ferritin levels, I generally tell them it's not fine, and that despite what they may have been told, that they are iron deficient and that it could be causing many of their symptoms.

I consider serum ferritin to be one of the most valuable (and inexpensive) labs I order on a regular basis for my patients, especially in menstruating women or anyone with persistent fatigue, and I'm going to tell you why.

Ferritin is a blood marker that represents total iron stores in the body. It's the earliest, most sensitive indicator of adequate iron stores.

Iron is an essential mineral, important for oxygen transport, energy production, red blood cell synthesis, and many more important biological activities.

Despite its importance, iron deficiency is the most common nutritional deficiency worldwide, and it’s something I see nearly daily in my clinical practice, yet it’s commonly missed or overlooked. Premenopausal women are more likely to become deficient due to monthly blood and thus iron loss, however, men may also become deficient in circumstances of malabsorption, increased blood loss, or occasionally in vegans and vegetarians.

Ferritin Fiasco's - Why the Controversy?

There are misunderstandings and misconceptions regarding what a person’s iron stores should be. Many doctors don't’ take symptoms of fatigue, restless legs, low mood, or exercise intolerance seriously until there is full-blown anemia (decrease in red blood cells). But the reality is that iron stores can be totally depleted without causing anemia (i.e., low ferritin levels).

You can still experience symptoms of low iron without being “anemic”.

In fact, as many as 84% of individuals without anemia, but with extremely low levels of iron, have symptoms.

So, how might you know if you have low iron levels? There are a few clues that your body is telling you it needs more iron!

Common Signs That You Could be Iron Deficient:

  • Fatigue, low energy, or lack of motivation

  • Shortness of breath or changes to your exercise tolerance

  • Hair loss

  • Low or depressive mood (or treatment-resistant low mood)

  • Increased susceptibility to infections and illness

  • Cognitive difficulties

  • Restless leg syndrome

  • Cravings for ice or other non-food items

If you have any number of these symptoms, it may be time to take a look at your iron stores.

Why Is It So Common To Be Iron Deficient?

There are many factors that lead to iron deficiency, though the main causes are usually liked to four main categories:

  1. Inadequate dietary intake (vegans or vegetarian diets low in heme [bioavailable] iron),

  2. Inadequate absorption of iron, commonly seen in gastrointestinal disorders such as Crohn’s, colitis, or small bowel overgrowth, or reduced bioavailability (read: absorbability) from non-heme iron sources or iron-binding minerals

  3. Increased blood/iron loss, as in heavy menstrual bleeding, gastrointestinal bleeding, acute blood loss (trauma), surgery, or clotting diseases, and lastly,

  4. Increased iron utilization, as in pregnancy, breastfeeding, and athletes.

The overall balance of iron intake vs iron losses can ultimately lead down of path of iron depletion and deficiency over time, or potentially iron replenishment and healthy iron stores.

Treatment of Iron Deficiency

The most common treatment for iron deficiency is oral supplementation. It sounds simple enough, however, there are many different forms and dosages available on the market. What makes things tricky is knowing which form of iron to choose, at which dose (specifically elemental iron dose and how that may be different than the label dose), knowing how and when to take the iron (or maybe more importantly, when NOT to take the iron), and the optimal method and interval to re-evaluate the efficacy of your supplementation and when to stop taking it.

The Bottom Line

Not all iron supplements are created equal and finding the right form, at the right dose is generally guided by a physician who is well-informed regarding optimal iron dosing and with follow-up lab values (i.e., re-checking ferritin and CBC to see how effective it is).

Don’t let people tell you it’s fine when it’s not. If you have had tests to evaluate your fatigue in the past, it may be time to ask for a second opinion.

For more information on fatigue, iron, ferritin, and more, please contact me or book a complimentary meet and greet or discovery call. Go To: Booking Page

In Health,

Dr. Randi Brown, ND


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