Ferritin and iron deficiency without anemia

This page does not contain medical advice; it is a compilation of what I have learned about ferritin (iron stores) in humans, with links to peer reviewed and other reputable source information. I do not earn any money from this site. My own health was changed profoundly once I addressed my iron deficiency and I wanted to share what I have learned.

You should discuss your health concerns with a medical provider, and if you choose to take over the counter supplements, be sure to have your levels checked to ensure you don’t have too much of anything.

Iron stores and anemia
Symptoms
Iron supplements
Dosing
Non-heme iron
Further notes on ferritin
Comments about lab work
Sources

Iron stores and anemia

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Anemia is when there are not enough red blood cells (CBC test); western medicine recognizes and treats this
Iron deficiency is the most common cause of anemia
Iron deficiency without anemia causes anemia-like symptoms but many doctors do not know this

	optimal iron stores	deficient iron stores	anemia
ferritin (µg/L)	>100	• mild (75-100) • moderate (30-75) • severe (<30)	typically <12
hematocrit (%)	normal range: •menses 36-48 •no menses 41-50	normal range: •menses 36-48 •no menses 41-50	•menses <36 •no menses <41
hemoglobin (g/dL)	normal range: •menses 12-15.5 •no menses 3.5-17.5	normal range: •menses 12-15.5 •no menses 3.5-17.5	•menses <12 •no menses <3.5

The way I think about it is that when iron stores dip below optimal, the body begins to triage or prioritize use of iron. Creating red blood cells is always going to be the most important, so it will always direct iron there at the expense of other functions; hence anemia is the “final stage” of iron deficiency. It’s kind of like running out of gas as the only way to know you need more. It works, but it’s a pain.

This document does not address the causes of iron deficiency which could be serious; iron deficiency should always be investigated under medical supervision to find (and possibly fix) the cause and monitor ferritin (i.e., when to move from “replenishment” to “maintenance”).

Symptoms

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Fatigue
Brain fog, memory and concentration issues
Shortness of breath (or air hunger)
Exercise intolerance
Dizziness
Weakness
Restless leg syndrome
Tachycardia
Feeling cold
Hair and skin issues (hair loss, dry or pale skin, brittle nails)
Easy bruising

Iron Supplements

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Oral iron comes in two types: heme and non-heme
- Heme is the kind found in animal tissue and blood (typically we get this kind from eating meat)
- Non-heme is all the rest: elemental iron (e.g., actual iron filings added to cereal and other fortified grains), iron “compounds” like ferrous sulfate, polysaccharide iron (like NovaFerrium and Feosol), iron found in all plants and vegetables, etc
Non-heme iron is cheap but is maddeningly difficult to absorb and has common side effects (see below).
Heme iron supplements are less commonly found and can be taken basically without any concern for absorption issues (except that absorption tapers off at single doses >40mg, so the total amount of iron should be split into multiple doses of 40mg taken 3 hours apart). Natural heme iron (i.e., iron found in meat) will be absorbed without concern for contraindications and really can’t be consumed in >40mg per serving (because that’s a lot of meat!)

Dosing

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“Most people with iron deficiency need 150-200 mg per day of elemental iron (2 to 5 mg of iron per kilogram of body weight per day)” (ASH guidelines)
Non-heme can be taken in 1 dose, split into multiple doses per day, or taken every other day
Heme iron should be 40mg (max) per dose; if more is needed split into doses separated by 3 hours
Be aware that bottles can be confusing: 325mg ferrous sulfate means the pill contains 325mg of the chemical compound “ferrous sulfate” but that contains only 65mg of elemental iron (bound into the ferrous sulfate structure)
Liquid iron may stain teeth

Your body also needs B12, folate (and vit c and vit d) to make use of your iron, so as you increase iron stores you also need to keep an eye on these values. B and C vitamins are water soluble so if you take too much your body will remove the excess via urine, so there isn’t really any harm in taking B&C

Some sources of heme iron supplements

Amazon has ProFerrin and HemeBoost with around 11mg iron per pill
Three Arrows https://threearrowsnutra.com with 20mg iron per pill (two kinds: with or without B vitamins added)

Non-heme iron

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Non-heme iron can be very difficult to absorb and many common foods hinder absorption.

Non-heme iron must be taken:

With Vitamin C
At least 1 hour before eating
At least 2 hours after eating
Adequate stomach acid (basically, not on PPIs)

But, non-heme iron must not be taken with:

Dairy or calcium
Grains, whole grains, bran
Fiber, including raw vegetables
Antacids
Caffeine
Certain antibiotics

Common side effects of non-heme iron include:

Nausea
Vomiting
Stomach pain
Diarrhea
Constipation (hard and/or sticky stool)

Further notes on ferritin

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ferritin and inflammation … certain conditions or inflammation can cause elevated ferritin so “normal” ferritin values may not reflect optimal iron stores; if symptoms of iron deficiency are present then iron deficiency can be investigated
Iron deficiency should be considered at ferritin levels below 30 to 45µg/L (AGA guidelines, Soppi papers)
Excess iron can be extremely dangerous and is called hemochromatosis so it’s important to check values regularly
iron absorption is regulated by the protein hepcidin
Ferritin is measured in µg/L …. 1µg/L = 1ng/mL
If you have been deficient for a long time, it will take a long time to replenish and feel better, and aiming for the higher end of the optimal range (say 200µg/L ferritin) may be a better idea

Comments about lab work

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Ferritin labs need to be drawn after fasting (i.e., before breakfast) and stopping all iron supplements for 48 hours before the test
Some notes about lab “reference values”
- The range of “normal” lab values are actually just the range of values that 95% of the lab’s population, which is assumed to be made up of healthy people. They aren’t specifically (i.e., functionally/objectively/scientifically) determined values (https://academic.oup.com/ajcp/article/133/2/180/1760481)
- “ranges have been set using population data” (Al-Naseem , 2021)
- “A reference range is usually defined as the set of values 95 percent of the normal population falls within” (from Wikipedia which cites Marshall & Bangert 2008)
Some doctors are very attached to lab reference values and ferritin above the lab reference range (often about 12µg/L) will be deemed “normal” by them and they will refuse to order monitoring testing (which is needed to confirm oral iron treatment is being absorbed and when to switch over to maintenance dose).

In the US you can have bloodwork drawn and labs done without consulting a doctor or health insurance