This website is dedicated to the millions of thyroid patients who are being ignored and left to suffer unnecessarily, and to healthcare practitioners, who want to better serve those patients.

Low Serum Ferritin/Hypothyroid Connection

Iron, in addition to iodine, selenium and zinc, are essential for normal thyroid hormone metabolism


Be careful when adding iron to your diet if you are hypothyroid, because taking iron within four hours of taking your thyroid hormone may interfere with the absorption of your thyroid hormone and make it less effective.


Pregnant women need to be particularly careful, as most pre-natal vitamins contain iron. You should take your prenatal vitamin, but plan to take it at least three to four hours apart from taking your thyroid hormone, or the iron in your vitamin may interfere with your body’s absorption of proper amounts of thyroid hormone.

Biologically, insufficient iron levels may be affecting the first two of three steps of thyroid hormone synthesis by reducing the activity of the enzyme thyroid peroxidase, which is dependent on iron. Iron deficiency, in turn, may also alter thyroid metabolism and reduce the conversion of the inactive T4 to the active T3, besides modifying the binding of T3. Additionally, low iron levels can increase circulating concentrations of Thyroid Stimulating Hormone (TSH)

That severe iron-deficiency leads to anemia as manifested by low haemoglobin and haematocrit on a CBC blood test is well known. However, mild iron-deficiency leads to low ferritin in blood tests BEFORE a drop in haemoglobin and haematocrit occurs. An article published in the May 2003 British Medical Journal showed that patients with low ferritin, but normal haemoglobin and haematocrit, have fatigue, that is reversed by iron treatment.

Treating Iron Deficiency

When a doctor suspects an iron deficiency, the first thing s/he will do is measure the blood level of a protein called FERRITIN.

Ferritin concentration indicates how much iron is stored in the body. Chronic infection, inflammation or certain diseases causing tissue and organ damage can produce a false reading. In the absence of one of these conditions, if ferritin is low, a doctor will usually assume iron deficiency and begin treatment. This holds true even if there is no obvious sign of anaemia.

The normal range for ferritin is usually between 30 and 300 mg/dL in men, but it is recommended that for everyone with a ferritin less than 60 mg/dL, they should be given iron treatment. The goal of treatment is to raise ferritin levels to a value between 70 and 90 mg/dL and this is usually achieved with oral iron treatment. Raising ferritin levels to this range may be needed for patients with hypothyroidism to have an optimal response to thyroid hormone treatment. Ferrous Sulphate (325 mg orally, available over the counter) is usually the recommended treatment. Doctors usually recommend one pill a day for a ferritin level between 50 and 60 mg/dL, two pills a day for a ferritin between 30 and 50 mg/dL and three pills a day for a ferritin less than 30 mg/dL.

Patients not responding to iron sulfate may be prescribed IV iron treatment (requiring a hospital visit). All iron products should be taken at least 4 hours after thyroid medication. After taking iron for three months, a ferrritin level should be re-checked and the dosage adjusted accordingly. Common side effects of iron treatment include constipation and black stools. Patients should increase the fiber and fluids in their diets to avoid constipation. Patients may need a stool softener such as colace, also available over the counter

A three-month course of therapy for the treatment of iron deficiency is recommended. Some authorities, however, advise patients to continue iron supplementation for six to twelve months. Whichever approach your doctor chooses, it is important that you add more iron in the form of iron-rich foods to your diet and that your doctor treats any correctable cause of blood loss. Patients with ongoing blood loss that cannot be corrected may need, in addition to eating a more iron-rich diet, to continue taking low-dose iron supplements indefinitely.


What many people don’t know is that iron plays a key role, not only in the body’s oxygen transport and delivery system, but also in the regulation of metabolism. Iron is needed to synthesize vital substances such as the brain chemical, dopamine, DNA and white blood cells. Thus iron deficiency can do much more harm than merely causing anaemia; it can have widespread effects from damaging a person’s ability to think to weaken their resistance to infection.

It is a common misconception that the amount of iron our bodies absorb is directly related to the amount of iron we eat. While we do get most of our iron through food, getting enough iron is not quite as simple as eating well. For one thing, the ability of our digestive system to absorb iron from the food we eat varies; e.g., those who are iron deficient do not absorb iron as well as those who are not.

Because dietary iron comes in different forms, the percentage of dietary iron absorbed depends on the type of food we eat and what other foods are being eaten at the same time. For example, iron from meat is easier for the body to absorb than iron from vegetable and other sources. In addition, iron absorption can be greatly increased or decreased by various factors. Certain salts, which store iron and other minerals in plant matter, interfere with the ability of the human intestine to absorb them. Chemicals called polyphenols in tea, coffee, cocoa, spinach and oregano inhibit iron absorption as well. Eating more ascorbic acid, which is common in fruits, vegetables and fortified cereals, can improve iron absorption. Calcium inhibits the absorption of iron by an unknown mechanism. This is probably why studies show a correlation between high milk intake and iron deficiency.


Many people, including those suffering hypothyroidism, because this can result in a lowered production of hydrochloric acid that in turn leads to the malabsorption of iron. Iron deficiency can also lower body temperature (common for those who take thyroxine), which causes fewer red blood cells to be produced. Additionally, being hypothyroid can result in heavier periods, causing more iron loss.

Women in their childbearing years have greater iron needs than men as a result of menstrual blood loss, the increased iron demands of pregnancy and blood loss during childbirth. In addition, anything that causes heavier than normal menstrual periods, for example uterine fibroids, may lead to iron deficiency. Adolescent girls are at particular risk because, out of concern for their weight, many follow diets that reduce the amount of meat they eat at a time in their lives when their iron needs are increasing. Iron deficiency can also be caused by other types of chronic blood loss, including internal bleeding from gastritis and ulcers, inflammatory bowel disease, parasitic infections (this is more common in Third World populations than developed countries) and haemorrhoids.
The best way to prevent iron deficiency is to educate yourself about your iron needs and the best iron sources, and to use this knowledge to make sure dietary intake keeps pace with your body’s demands. Recommended dietary allowances (RDAs) for men over the age of 19 and women over the age of 51 are 8 mg per day; for women aged 19 to 50, the RDA is 18 mg per day. In a typical European diet, major sources of iron are meat, poultry, fish, nuts and seeds, legumes and bean products, green leafy vegetables, raisins, whole grains and fortified cereals. The iron content of some popular high iron foods is shown in Table 1 below:

Table 1. Iron Content of Selected High-iron Foods.
Food Portion Size Iron (mg)
Total® cereal 1 cup 18
Grape Nuts® cereal 1/2 cup 8.2
Instant plain oatmeal 1 packet 6.7
Wheat germ 1 ounce (1/4 cup) 2.6
Broccoli 1 medium stalk 2.1
Baked potato 1 medium 2.7
Spinach 1 cup raw 0.8
Dried peach 5 halves 2.6
Raw tofu 1/2 cup 4
Lentils 1/2 cup 3.3
Kidney beans 1/2 cup 2.6
Chickpeas 1/2 cup 2.4
Beef chuck 3 ounces 3.2
Dark meat turkey 3 ounces 2.0
Blackstrap molasses 1 tablespoon 5.0

Recognising the Risk

You can assess your risk of developing iron deficiency by looking for the major risk factors: an iron-poor diet, unusual blood loss, a history of iron deficiency and actual symptoms. A good way to do this is to ask yourself the following questions:

1. Do you consume two or more portions of meat, fish, chicken, nuts, seeds or legumes per day?

2. Do you eat at least six servings of grains per day?

3. Do you generally eat at least one serving of fruits or vegetables containing foods at the same meal as grains or beans?

4. Do you take a calcium supplement or over-the-counter antacid at every meal?

The first two questions ask about consumption of iron containing foods. The third and fourth questions ask about consumption of foods that may affect iron absorption. If you answered no to one of the first three questions or yes to the ast question, you may be at risk for iron deficiency.

Menstrual and Other Blood Loss

5. Do you soak through your tampons or pads?

6. Does your period last longer than six days?

If you answered yes to either of these questions, you may be at risk.

Other causes of blood loss to look out for are gastrointestinal, urinary or pulmonary bleeding. Any patient with one or more of these types of blood loss should seek medical treatment or, if they are being treated, raise the issue of iron deficiency with their doctor. Another relatively common cause of increased iron requirements is frequent blood donation. Anyone who donates blood regularly should be screened for iron deficiency during his or her annual check-up.

History of Iron Deficiency

7. Have you been treated for iron deficiency in the past?

Even if a previous iron deficiency problem was treated and easily corrected, whatever caused the deficiency may remain, and the deficiency may recur. For this reason, anyone who has been diagnosed with iron deficiency in the past should be periodically re-evaluated.

Signs and Symptoms of Low Serum Ferritin (many mimic symptoms of hypothyroidism)
General lethargy
Unusual fatigue after exercise
Pica (compulsive eating of non-food items)
Pagophagia (compulsive eating of ice)
General weakness
Fast heartbeat
Loss of libido
Brain fog
Hair loss
Faintness and breathlessness
Long or unusually heavy menstrual periods
Paleness of the skin or ey
Intestinal problems Cognitive problems such as impaired learning ability and spoon nails (thin and concave fingernails
Bruising that occurs without reason

Anyone having any of the above should see a doctor as soon as possible to get their Serum Ferritin level tested.


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