The Ferritin Level Test

The ferritin test may be the most important blood test you ever get, especially if you have a thyroid problem.

When I began my training in the diagnosis and management of internal disorders immediately after graduation, one of the first things we studied heavily was blood chemistry analysis.  My teachers always stressed the importance of taking a careful look at iron levels in the blood and a rare test known as the ferritin test.

What is ferritin?

Ferritin is an iron-containing protein and is the primary form of iron stored inside your cells.  Even though there is a small amount of ferritin released into your bloodstream, it is an accurate marker of how much iron is actually stored in your body.  Iron is primarily stored in your liver, muscles, spleen and bone marrow but if you have too much it can accumulate in your organs and the brain.

The ferritin level blood test measures the iron stored inside your cells

You either have too much iron, too little or just the right balance in your body and the ferritin test can give us an excellent picture of how much iron is actually stored in your body.  Iron is found in your red blood cells but it also accumulates in your organs and tissues.

Iron is important for healthy oxygen transport throughout your body so you can see how vital it really is for your health.  Too little iron will result in anemia which basically means that your red blood cells cannot carry enough oxygen to your cells and you start to develop signs of oxygen deficiency.  Signs of anemia include:

  • Weakness
  • Dizziness
  • Headaches
  • Pale skin
  • Fatigue
  • Low body temperature
  • Memory loss
  • Hair loss
  • Poor brain function
  • Hypothyroidism
  • Adrenal fatigue
  • Spoon-shaped finger and toenails
  • Smooth tongue
  • Burning sensation in the tongue
  • Sores at the corners of the mouth
  • Dry skin
  • Shortness of breath
  • Ringing in the ears (tinnitus)
  • Leg pains
  • Chest pain
  • Pica (cravings for specific substances, such as licorice, chalk, dirt, or clay)

Too much iron can have the opposite effect because iron creates a lot of oxidative stress which is basically too many free radicals that create inflammation.  These free radicals eat up your antioxidants like vitamin C and E creating deficiencies.

Menstruating females lose a small amount of iron every month during their cycle so they tend not to build up too much iron in their bodies.  However, iron levels can get too low when your diet is deficient in iron and you have absorption issues due to things like gluten and gut infections.  I tend to see low ferritin levels quite a bit in chronically-ill women who are still cycling but it is also common in postmenopausal women who never restored their iron levels before entering menopause.

Since men do not have a menstrual cycle, we are the most at risk for accumulating iron.  As iron builds-up in a man’s body he may develop the following symptoms as it accumulates in the brain and other body tissues (most of these also apply to women):

  • Brain fog
  • Fatigue
  • Low sex drive and erectile dysfunction (iron accumulates in the testicles)
  • Mood swings, especially anger
  • Digestive problems as iron builds-up in the gut
  • Anxiety
  • Depression
  • Fatigue after meals (insulin resistance)
  • Memory loss
  • Joint pain
  • Weight loss
  • Abdominal pain
  • Hair loss
  • Congestive heart failure

Iron is extremely “heavy” in the bloodstream so it forces the heart to work harder as it pumps this heavy metal through your blood vessels resulting in blood pressure changes and more inflammation in your arteries.

This is where the ferritin test is so important because it can tell us if there is too much or too little iron in your body.  It’s a simple blood test but rarely ordered during general check-ups and standard blood panels however I believe it is one of the most important and overlooked tests in medicine today.  This is why I include it in every patient’s blood panel even if it was normal within the last year.

What should you do if your iron levels are too low?

One extremely important fact to note is that your iron levels can become depleted due to internal bleeding from serious diseases such as cancer or an ulcer in your gut.  If you or your doctor suspect serious disease then you should be evaluated by a gastroenterologist, internist or hematologist to rule out something more serious.

If your iron is simply low due to insufficient dietary intake or absorption problems then you can begin to take the following steps to restore your levels:

  1. Iron supplementation.  Iron is best taken in a chelated form with food for the best absorption.  Combining iron with vitamin C will help it’s absorption.
  2. You may require intravenous or iron injections by a hematologist if your ferritin levels are extremely low.
  3. Indentify food sensitivities such as gluten which can create absorption problems.
  4. Get your thyroid checked since low thyroid function results in low stomach acid which will negatively affect absorption of vitamins and minerals.
  5. A stool analysis may be in order to identify infections such as parasites, bacteria or yeasts that can also create poor absorption.  In fact, some parasites such as worms feed on iron and b-vitamins resulting in deficiencies.
  6. Increase your consumption of iron-rich foods.

Additionally, you may want to limit your consumption of the following which inhibit the absorption of iron (these can be used if your iron is too high as a treatment strategy):

  • Calcium supplements and calcium-rich foods
  • Eggs
  • Phytates: Reduce iron absorption about 50% (nuts, seeds, legumes, cereals, whole grains).  Proper preparation of these foods such as soaking and sprouting significantly reduces the phytate content.
  • Oxalates:  spinach, kale, beets, nuts, chocolate, tea, wheat bran, rhubarb, strawberries and herbs such as oregano, basil, and parsley.
  • Polyphenols:  cocoa, coffee, black tea, herbal teas, green tea, berries, walnuts, apples.

If you have too much iron in your body then you may have a genetic condition known as hemochromatosis.  This disease basically means that  your body is absorbing too much iron so it builds-up in massive quantities.  It can be deadly if not found early as iron continues to build resulting in heart attack and organ failure.  Hemochromatosis is handled by a gastroenterologist or hematologist who will have you do frequent therapeutic phlebotomies to reduce your iron levels.  This usually works quite nicely to get iron levels down to a healthy level and then you must be monitored and prescribed a schedule for regular phlebotomies or blood donations to keep your iron levels in a healthy range.

Additionally, there are a few things you can do to keep your iron levels low and reduce the oxidative stress from the excess iron:

  1. Drink green tea.  This will inhibit iron absorption and the antioxidants in green tea will help reduce inflammation.
  2. Increase consumption of the spice turmeric or supplement with curcumin.  This has actually been shown to help your body get rid of excess iron.
  3. Stop cooking on iron cookware which can result in iron in your cooked food.  I only recommend menstruating females to eat off of iron cookware.  I have seen many patients over the years who use iron cookware and their iron levels have built up to an unhealthy level.
  4. Decrease consumption of foods that are high in iron.  Red meat has the highest level of iron which is great if your iron levels are low, but not so great if they are too high.
  5. Be careful with vitamin C supplements since vitamin C improves absorption of iron.  Some say the antioxidant effects of vitamin C cancel out the negative effect of increased iron absorption, but I recommend just not going overboard if you are going to take it.
  6. Avoid alcohol, sugar, nicotine, and beta-carotene which all increase the absorption of iron.

Iron and your thyroid

Too much iron can build-up in your thyroid gland creating inflammation and imbalanced hormone production.  However, iron is required for thyroid hormone production, the conversion of T4 into the more active T3, and for utilization of thyroid hormone in the cell, so your ferritin levels must be healthy for optimal thyroid hormone levels.  I have found that low ferritin levels have been the missing link in some patients with hypothyroidism who just can’t seem to get their thyroid levels in balance.  If you have a thyroid problem, definitely have your ferritin levels checked to make sure your ferritin is not too high or too low.

Click here to read my detailed article on ferritin and hypothyroidism.

Iron at war?

Too much iron can create an internal battle among iron and the following nutrients:

  • Zinc
  • Manganese
  • Molybdenum
  • Copper

As iron accumulates in your body, you may develop deficiencies in these vital nutrients which are key factors in hundreds of processes in your body.  I have patients do a “Zinc Taste Test” every 30 days to check their Zinc levels.  If they are low, we supplement with Zinc and a small amount of Copper for 30 days and then retest on a regular basis.  Just as iron competes with these 4 nutrients, they also compete with each other so it’s a matter of finding the right balance and not taking too much of one of these for long periods of time so you don’t develop deficiencies.

What is a healthy ferritin level?

Standard lab ranges are pretty broad currently set at 15-150 ng/ml for adult women and 30-400 ng/ml for adult men.  I prefer a ferritin of about 70-150 for optimal health.  Some women need to have a ferritin at 100 or above just to start seeing hair regrowth, to normalize thyroid function, and to really feel better.  It’s amazing how symptoms can set in when the ferritin drops below 100.  One other important thing to note is that your ferritin levels can be extremely low but you may not show signs of anemia on standard blood tests.

Are there other tests you should have?

You should also have these iron values tested along with ferritin to get a more accurate picture:

  • Serum iron
  • % iron saturation
  • TIBC (Total iron binding capacity)

If you only check ferritin without the above three markers then you’re not getting the complete picture.  If the above markers are elevated along with a normal or low ferritin, then it most likely isn’t a good idea to supplement with iron.  If the above three are elevated then your blood and cells are saturated with iron and it isn’t being used properly by your body.  This could be due to liver dysfunction, hypothyroidism, B12, or folate deficiency.  You don’t want to dump more iron into a system that is overly saturated.

If however the % iron saturation and TIBC are low and your serum iron is normal or low along with a low ferritin, then it can be safe to start supplementing with iron.  Have these levels checked every 6 weeks until all your markers normalize.

The ferritin test is by far one of the most important tests you can have done on a regular basis yet it is almost never ordered by conventional doctors.  Make sure you request it the next time you have a check-up.  It just may be the missing link if you aren’t feeling your best.


Ferritin and Hypothyroidism >

Hashimoto’s Thyroiditis Natural Treatment >

The thyroid adrenal pancreas axis >

The gut thyroid connection >

The-thyroid-and-thyroid-hormones >

Best Diet for Hashimoto’s Disease >

What are optimal thyroid antibody levels? >

All about autoimmune thyroiditis >

"I highly recommend that you work with him to get your life back. I am in control of Hashimoto’s and not the other way around.”

by - Theresa


22 thoughts on “The Ferritin Level Test

  • November 13, 2019 at 1:55 pm

    So what if my iron saturation is at 29%, iron value is 126 mcg/dL, transferrin is at 306 mg/dL yet my iron storage is at 21ng/mL? I have so many terrible symptoms yet my docs say my blood work is fine. I also had my thyroid tested and all levels came back fine for that. I’m not anemic according to my other bloodwork. I feel like nobody hears me and they all make me feel crazy. When I look up iron deficiency symptoms it describes what I’m feeling. I had to actually go to another doc who was willing to test my iron. They tested but said it’s fine. I’m thinking I need to get my ferritin levels higher. I at least wanna try because I want these symptoms to stop!!

    • November 13, 2019 at 2:11 pm

      Each person is so unique that it is important to get a comprehensive functional medicine evaluation to figure out why you’re not feeling well. Please contact our office if you’d like to work together or we can recommend another practitioner.

  • November 17, 2019 at 8:20 pm

    Is there a relationship between long term use of Lansoprazole and low ferritin?

    • March 11, 2020 at 7:04 am

      I’ve been experiencing hair loss for well over 2 years now. I’m a 34 year old female with mild PCOS and Insulin Resistance and hypothyroidism. My weight is healthy, my menses are not heavy, and my A1C and TSH are always very normal. I had blood work recently. These are my results:
      Ferritin: 42
      % iron saturation: 24
      iron binding compacity: 301
      iron total: 73
      folate serum:>24
      vitamin b12: 816
      T3 total: 71
      Thyroid Peroxidase: 1
      DHEA sulfate: 180
      My question is, do you recommend an iron supplement with these levels? I know my ferritin is not optimal, but I’m struggling to understand it’s relationship with TIBC and % saturation. Thank you so much!

  • November 20, 2019 at 4:31 pm

    I started with a ferritin level of 2 and after iron infusions it increased to 53, 2 months later it is 14. I have had every blood test from the Hemotologist/Oncologist, endoscopy and colonoscopy and everything is normal. The Dr. says my thyroid levels are normal, however I have all the symptoms of Hypothyroidism and my mother has hypothyroidism.

    • November 20, 2019 at 4:43 pm

      It sounds like something is missing that has not been evaluated. There are a number of tests that functional medicine practitioners will run to identify why this is happening.

      • November 20, 2019 at 6:03 pm

        What do you think could be evaluated?

        • November 21, 2019 at 5:13 am

          This would require a full evaluation to figure out what is out of balance. Medical advice cannot be given on a blog comment section for many reasons. We would be happy to review your case or help you find someone who will do the proper detective work.

        • April 12, 2020 at 6:36 pm

          Thank you for this information! I’ve been iron deficient for years and it was easily corrected with iron supplements. My ferritin is now 174 and I have been having high BP along with fatigue. I know it’s not extremely high but we are all different, so maybe it’s too high for me? My question is, how accurate are ferritin tests? I’ve read that it can be inflated by inflammation and other things that mean the test result could be off? True? all my other labs were perfect, my iron panel, my electrolyte panel, my CBC, my thyroid panel, magnesium, liver and kidney.

          • April 14, 2020 at 12:08 pm


            Ferritin tests are very accurate as long as they are interpreted by a doctor who understands the test. There are many factors that can affect ferritin levels so be sure you’re working with a doctor closely to make the best decision.

  • January 2, 2020 at 6:19 am

    Hello Dr,

    Is it true that there are a couple of very specific situations in which both Vitamin D and Iron (Ferritin) will be low at the same time and they require the proper clinical evaluation instead of supplementation? A good example of that is some type of microbial infection including something parasitic. The body as a defensive mechanism will shut down iron production and remove storage iron to prevent the infection from spreading and downgrade vitamin D so that it cannot be taken up as efficiently in the cilia of the intestine.

    So, first question is always why are they low to begin with because supplementation can cover up a problem where these were the only symptoms or it can functionally help an infection to spread by supplementing. Does supplementing with it will help an infection to spread?

    Thanks and regards!

  • April 19, 2020 at 2:44 am

    I have had an extremely high ferritin level for the last 3 years. My last ferritin level was 1035. Everytime I see my doctor they always tell me its probably just NAFL Disease. Im very concerned about it so my doctor referred me to GI to try and get some answers. I eat very little meat. I exercise (not as much as I should). I have been tested for hemochromotosis and it was negative. Please help

  • May 17, 2020 at 5:50 pm

    My daughter was diagnosed with hashimotos. It took a long time to find a Dr who would do tests I asked for. In 2018 her total iron was 104 (range 27-164) iron binding was 355 (range 271-448) saturation 29(range 8-45) and ferritin 15 (range 6-67) she is on 400 of thyrovanz which blood work last week showed her ferritin serum is now 21 (range 15-150). Dr just lowered her thyrovanz to 300 but no other iron panels were done. Since she is hashi is there anything to take to raise her ferri tin? She also has high rt3 which is 21.7 ( range (9.2-24.1). Tsh is <0.005 which is why he said she's over medicated. Do you have any advice. Its always been low ferritin/high rt3. We have been to so many drs that I'm at the end of my rope. She gained so much weight and can't sleep. She also has anxiety. Thanks for any help.

    • May 18, 2020 at 7:03 am

      Cheryl, The key is find out why her ferritin is low which could be for many reasons. She would need a thorough history and lab testing to find out the causes of her imbalances. We work with children so don’t hesitate to contact us for help.

  • June 19, 2020 at 7:48 pm

    Omgoodness this is an awesome article! I just found out “iron on the low side” this wk. I’m a 45 yr old nurse with mild CP. For the last 10 yrs dealing with discreet episodes of lower extremity weakness– but for last 8 yrs decline of stamina, increased fatigue, muscle weakness, muscle burning with little exertion.. shortof breath with little exertion. . I’ve been thru muscle biopsy and testing… nothing to explain. Gotten to point that I’m more sedentary and gained weight. So I blame all these symptoms on being overweight, outta shape, depression worsening… I’m lazy. Asked PCP to check iron this visit because I’m chewing ice like crazy. My ferritin is 6. Iron 36. % sat is 8. ……
    Doesn’t seem concerned… start daily dose iron..I have never been anemic..never had iron study…. this could be part of my symptoms all along?!
    Taking prilosec 40 daily for 12-15 yrs…hiatal hernia, gerd. PCP says could maybe contribute to my low #.
    Why isn’t he concerned or trying to find cause??? Seems underwhelmed. For me this could be life changing…. I’m optimistic. I’ve been suffering and all this time?????…. maybe I will feel like and want to and be able to do things other than work and home!
    Again very helpful article….our lab range for ferritin has 5 as the low #…seems criminal.

    • June 22, 2020 at 8:53 am

      Charity, It sounds like you’ve been having a difficult time and no one is addressing your core issues. Now you have the information you need to get things turned around with your doctor.

      • September 16, 2020 at 9:49 am

        Can high ferritin levels mimic arthritis symptoms or how are the two related? And how might high levels be related to poor circulation?

  • June 29, 2020 at 6:44 am

    I’m curious to know more about the “optimal” range for ferritin levels. I’ve been feeling exhausted (though I have two kids, a nursing baby who still doesn’t always sleep well, and a full time job so maybe it’s just good old fatigue!) and recently got blood-work done to make sure there were no underlying health concerns. My ferritin level is well within the “normal” range (45) but the range is so large. The doctor I saw (I live outside the US now) said that it was really good for a woman who had had a baby and there was no need to supplement. However, this article seems to indicate that one would have a more “optimal” health at a higher level. I certainly don’t want to self-supplement considering that too much iron is not good. But I wonder if I should try and find another doctor to re-evaluate this? I am a 35 year old female. Thanks!

  • September 9, 2020 at 6:23 am

    I really appreciate this post. I’ve been looking all over for this! Thank goodness I found it on this blog. You have made my day! I think this is an engaging and eye-opening material. Thank you so much for caring about your content and your readers.

  • October 23, 2020 at 11:46 am

    Hello Dr. Hedberg,

    My daughter is 16 years old and is always tired. Her iron is 127 and ferritin is 48 and the doctor told her to take methylated folate with vitamin c, but she is still very lethargic. Should her ferritin level be higher than 48? Should she be taking this folate supplement? Two years ago she had a lot of hair loss around her temples and a different doctor at the time had her take selenium which helped with the hair loss. Her menstrual cycles are imbalanced. She has very light periods that are dark in color.


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