Iron deficiency and hair loss
Iron deficiency and hair loss


The five major minerals that are crucial for normal biological function are calcium, potassium, sodium, phosphorus, and magnesium.  The remaining minerals are trace elements, and these have a specific biological function in the human body, they are sulphur, chlorine, cobalt, copper, zinc, manganese, molybdenum, iodine, and iron.

Iron is the most common deficiency worldwide and a well-known contributor to hair loss, though to remains unclear to what degree. Iron is required for the transport of oxygen, DNA synthesis. cellular energy, and numerous biochemical activities. While the exact mechanism of action that negatively impacts hair growth is still unknown, it is thought that iron deficiency could contribute to hair loss via its role as a cofactor ribonucleotide reductase, and enzymes that controls DNA synthesis.

iron deficiency and hair loss


DNA is a set of instructions that tells cells what proteins to produce, in the case of keratin cells that make up the hair fibre, one instruction DNA provides is to make keratin, lots and lots of keratin.  In addition to the role of iron in DNA synthesis, several genes identified in the hair follicle are in some part regulated by iron availability.

Iron also plays a vital role in the production of ATP from food, ATP is the body’s main source of energy and low levels of ATP will result in slow growing and thinning hair.  Keratin cells have a high energy requirement and are particularly sensitive to reduced ATP production.


Anaemia is a condition where iron levels fall way below the levels required for adequate cellular growth.

Essentially, there is a line in the sand that takes you from being clinically normal to the oxygen deprived depths of anaemia.

Iron deficiency is the ‘no man’s land’ between anemia and normality, this area is poorly defined.  Without recognising iron deficiency as a separate condition, it suggests that you can go from normal to anaemic within a short period, without a relative and significant decline in metabolic function.

Many women exist in the parameter of iron deficiency without ever becoming anaemic but deal with many of the symptoms associated with iron deficiency anemia.  Low iron levels impact the liver which is vital for the uptake of fat-soluble vitamins (A, D, E and K), blood sugar regulation, thyroid hormone conversion (T4-T3) and immune tolerance.

Symptoms of iron deficiency are non-specific, making it more difficult to establish.  If you are los in iron you may experience constipation, fatigue, cracked lips and hair loss

Iron deficiency hair loss


Iron deficiency affects the hair growth directly, and indirectly, in several ways.  Iron is essential for the production of hemoglobin, a complex that allows red blood cells to carry oxygenated blood throughout the body.

Hemoglobin can also form a complex with carbon dioxide allowing removal from cells to be transported to the lungs.

Research indicates that, amongst a number of factors, hair follicles need a hemoglobin level of at least 130 g/L to receive enough oxygen to remain in anagen. This specifically must be hemoglobin at 130 g/L with an adequate number of mature red blood cells in circulation for 110 to 120 days.

The requirement will be slightly higher ( more than 140 g/L) if there has been a prolonged history of hair loss (1 year or more).  Whilst the level of hemoglobin is important the number of red blood cells in circulation should also be considered.

iron deficiency and hair loss


Iron has been shown to support the anchorage of the hair follicle due to the intrinsic biomagnetism of the human hair follicle.  This magnetic field is a result of electron movement that contributes to the induction of electromagnetic fields.

Electromagnetic fields influence a range of functions that affect keratin cells.  Documented effects include induction of heat shot proteins (to support protein formation), enzyme activity and the regulation of intracellular calcium levels.


There are number of reasons why iron levels may be low:

Low dietary intake | To maintain adequate iron levels it is important to eat iron rich food regularly.  There are two forms of iron found in food: non-heme and heme iron.  Non-heme iron is found in grains, legumes or leafy greens or such as lentils, spinach and nuts.  Heme iron is derived directly from hemoglobin, it is found in meat, poultry and fish.  Heme iron is easier to absorb than non-heme iron.  The recommended daily allowance for iron is 15 mg per day, this is the average daily intake found to be sufficient to meet the iron requirements of 98% of healthy people.

Heavy periods | Women who have heavy periods are at risk of iron deficiency or anemia.  The total amount of blood loss during menstruation ranges from 5.5 – 169 ml, the average blood loss is 37.1 ml.  A blood loss of 40ml will yield an average loss of 1.6 mg of iron (with an average hemoglobin concentration of 125 g/L), regular blood losses of over 80 ml per cycle will deplete iron stores and eventually lead to an iron deficiency.

Malabsorption | When you consume food containing iron, it is absorbed into your body through the small intestines.  Components found in food such as phytic acid can reduce absorption by binding iron tightly making it unavailable for absorption. Impaired iron absorption can also occur after some forms of gastrointestinal surgeries or any with abnormalities of the gastrointestinal tract such as Crohn’s disease, inflammatory bowel syndrome, H.pylori infection or celiac disease.

Liver disfunction | The liver is the main site of lymph production, lymph allows easy access of iron to the blood stream from the intestines.  Bile salts found in bile produced by the liver also affect the efficiency of iron uptake by the microvilli.  The liver also regulates the uptake of iron by synthesising hepcidin, this hormone plays a role in controlling red blood cell production, trapping iron to lower available iron and restricting the absorption of iron in the intestines.  Consistently high levels of anemia lead to a condition called anemia of chronic disease.  Liver function is affected by alcohol, nicotine, medication and caffeine as they all pressure the liver to work faster and harder.


The role of iron deficiency in hair loss has been reported for nearly a century.  Although iron has been linked to hair loss, blood tests often report normal results when serum iron parameters are investigated.

Dr Rajendrasingh Rajput investigated the effects of iron supplementation in women that had normal levels of hemoglobin that were below 130g/L.

To evaluate the efficacy of this low dose therapy, results were compared against minoxidil.  Minoxidil is a hair loss medication, proven to be effective in encouraging hair regrowth in cases of hair loss.  The treatment involved iron and nutritional therapy (zinc, magnesium, selenium, fatty acids, vitamins A/C/D) to support iron uptake and metabolism.  The additional nutrition support also neutralised free radicals and provided a low dose of biological catalysts.

Hemoglobin increased by an average of 10g/L after 4 months and this gave a 12% increase in hair density after 6 months.  Hair loss was controlled within 3-4 weeks and all 20 women saw a varying amount of improvement within 2 months.

The combined therapy was found to be significantly more effective than minoxidil alone.


How long hair takes to regrow after replenishing iron stores will depend on the level of deficiency at the start of treatment.  It may be necessary to address zinc levels at the same time as the two deficiencies are often found together.

Low levels of vitamin D also contribute to iron deficiency due to its relationship with hepcidin.  Hepcidin is an iron uptake inhibitor and can contribute to iron deficiency even when dietary intake is sufficient.

The first signs of hair regrowth are normally seen within 2-3 months.  This is usually a seen as an abundance of shorter hairs, there will be a reduction in grey hair and hairs shed daily.  A premenopausal woman must absorb an average of 2 mg daily to avoid iron deficiency once iron stores have been recovered.  You can request blood tests for hair loss diagnosis if you suspect you may have iron deficiency.


If you think you have an iron deficiency you should see a doctor.  Your doctor will investigate your medical history, carry out a physical exam and request blood tests to determine the severity of the condition.  A mild iron deficiency may show no outward symptoms and may only be picked up through routine blood tests.

When conducting a physical exam, a doctor may:

  • Listen to your heart to check for an irregular heartbeat
  • Check for rapid or uneven breathing
  • Press on your abdomen to feel for changes in spleen or liver size
  • Carry out a rectal exam to check for unusual breathing
  • Investigate possible gastrointestinal blood loss due to parasitic infection

In addition to physical exams a doctor might ask several questions about:

  • Your menstrual cycle
  • Your diet
  • Any gastrointestinal disturbances or regular bouts of constipation
  • Recent blood loss (possibly from nosebleeds or frequent blood donations).

Blood tests to support the diagnosis of iron deficiency anemia include:

Serum iron – This test measures the quantity of iron in the blood. Sometimes the levels of iron in your blood may be normal even if the total amount of iron in your body is low overall.

Transferrin saturation – Transferrin is a protein that shuttles iron around the body, when a transferrin protein is bound with iron it is classed as ‘saturated’.  Measuring the saturation determines how many transferrin proteins are not carrying iron.

Iron binding capacity – The approximate estimation of the serum transferrin level, this measurement is not exact as not all iron is bound by transferrin.  The test is performed by saturating the blood sample with a high amount of iron.  All the iron not bound to transferrin is removed and from this reading an estimation of the capacity of transferrin to bind iron can be worked out.

Hemoglobin – The level of hemoglobin is useful for determining the severity of iron deficiency.

Ferritin – Ferritin is a protein that stores iron, a measure of ferritin indicates how much iron is stored in the body.  Ferritin levels can also indicate inflammation or anemia of chronic disease.

Iron blood tests for hair loss


Vegans and vegetarians are at a higher risk for iron deficiency as their requirements are roughly 1.8 times higher than for those who consume meat. due to the lower bioavailability of non-heme iron found in plants.  Other groups at risk of iron deficiency are premenopausal women due to menstrual blood loss, or those with malabsorption disorders and chronic diseases.

Advanced and prolonged iron deficiency may eventually develop into iron deficiency anemia and require iron supplementation.

Iron deficiency and its link to hair loss has been contested by a number of studies with a number of studies showing no definite link between hair regrowth and iron supplementation.  Whilst iron is likely to be a major factor in hair loss, it is likely that a number of other nutritional imbalances play some role.


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