What is Iron?

The name for iron in Latin is ferrum and the current English name has been adopted from Anglo-Saxon English (Old English) word ‘iren’.

Iron is the fourth most abundant element found in the Earth’s crust, both in the inner and outer core and on the periodic table iron can be found with the symbol Fe and atomic number 26. In the body iron is also one of the most abundant mineral required for a variety of functions.

Health benefits of Iron

The following are some of the many health benefits that iron has on the body:

Treats anemia and fatigue  

Iron is essential for the correct function and production of hemoglobin, an important componenet of red blood cells for the process of carrying oxygen from the lungs and around the body. A lack of iron means a lack of oxygen-carrying red blood cells which can lead several health problems including anemia with symptoms manifesting as a lack of energy and weakness.

One of the most commonly known health benefit or iron in the body is treating anemia. In fact a deficiency of iron is the main cause of anemia although there are other nutritional deficiencies that can also lead to anemia such as vitamin B12 and copper most of which are required for the absorption of iron. In some studies some of the nutrients that help absorb iron in the body have also shown to reverse iron related anemia. [1]

Many anemia related symptoms which includes fatigue are associated to iron deficiency but are also linked to poor absorption of iron through a deficiency of synergistic nutrients such as copper.

When treating anemia it is also important to consider the deficiencies of other nutrients such as copper, B12, C, A and other factors such as the presence of phytates in the diet all of which if left out of balance can impair iron absorption. Many of the complex B vitamins are important as they work synergistically with various minerals in the body which includes iron. [2]

Boosts Immune Function

In addition to keeping anemia at bay, iron also helps boost the immune system through its role in the production of red blood cells. Red blood cells help transport oxygen throughout the body and involved in the healing process and repair of cells, tissues and organs. [3]

Improves muscle health

Irons role in the oxygen transportation around the body has a direct impact on muscle strength and health. A deficiency of iron can often manifest as muscle spasms. In addition to this iron helps restore energy levels by providing oxygen throughout the body and eliminating weakness in the muscles.

Potentially reduce symptoms of PMS

Although research is lacking in this area some of the symptoms of PMS are associated with iron deficiency which can occur from heavy bleeding. It’s important for menstruating women to receive an adequate intake of iron and nutrients that help with iron uptake. [4]

Maintains healthy looking hair, skin and nails

Iron and copper work together to maintain healthy color and appearance of hair and skin. Copper deficiency is a sign of low iron or poor absorption of iron as copper is required for its absorption. A lack of iron can cause hair and skin becoming dry and brittle. Low iron reduces hemoglobin which is necessary for transporting oxygen around the body and as a result can cause unhealthy looking nails, pale and dull looking skin.

Helps maintain thyroid health

Iron is involved in maintaining thyroid health. Thyroid health conditions such as hyperthyroidism and hypothyroidism are linked to the imbalance of various nutrients which includes iron. Symptoms of thyroid conditions also include anemia. Although the anemia is usually induced from low levels of copper it is also partly due to poor absorption of iron which needs correct amounts of copper to maintain absorption.

In addition to iron, copper and zinc need to be balanced as these nutrients are antagonistic and can compete for absorption. [5]

Agonist / Synergist

Vitamins: A, B1, B2, B3, B6, B9, B12, C, E,

Minerals: Cr, Cu, K, Mn, Na, P, Se

Other: Hydrochloric acid (HCI)

Vitamins A, B9, B12, and C are needed for iron absorption as well as other B vitamins.

The minerals copper, calcium, molybdenum and manganese are needed for iron absorption.

Vitamin A increases iron absorption and non heme iron which is usually less absorbed than heme iron. [6] [7]

Iron increases bioavailability of pro vitamin A carotenoids which includes alpha-carotene and beta carotene. [8]

Iron is need to convert beta carotene into retinol. [9]

Vitamin C regulates uptake and metabolism of iron. [10]

Vitamin C increases absorption of non heme iron, and also when iron is present with substances that would normally inhibit absorption. [11] [12]

Vitamin C helps counteract the short term inhibitory effect of calcium on non heme iron absorption. [13]

Copper and iron work synergistically for the formation of the oxygen carrying molecule hemoglobin and both need to be in the correct ratio with some studies showing benefits of about 5:1 ratio. [14]

Vitamin E as part of antioxidant therapy has shown to improve therapeutic iron supplementation by preventing inflammatory response. [15]

Hydrochloric acid is needed for iron absorption, iron needs an acid environment for proper digestion and does not digest well with high alkaline foods. Iron is better absorbed with acidic food.

Digestive enzyme that can promote hydrochloric acid may be helpful for iron absorbption for those with low levels of hydrochloric acid.
Iron absorption is dependent on stomach acid with research suggesting better absorption with low pH of stomach acid (hydrochloric acid). [16]


Vitamins: E

Minerals: Ca, Cu, Mn, P, Zn

Metals: Al, Hg, Pb

Other: Phytates, oxalates, caffeine (tea, coffee), high intake of indigestible fibre (roughage), low hydrochloric acid.

High levels of calcium decreases short term absorption of non heme iron but does not affect in the long term. [17] [18]

Iron reduces vitamin E absorption. [19]

Vitamin E deficiency can lead to toxic build-up of iron. [20]

Vitamin E and iron compete for absorption and should be taken separately. High intake of vitamin E can reduce iron absorption. [21]

High copper can reduce iron absorption and high levels of iron can reduce copper absorption. [22] [23]

Manganese inhibits iron absorption. [24] [25]

Excessive zinc intake can deplete iron level as it competes with iron for absorption. [26] [27]

Food sources of iron

Food sources of iron include red meat (lamb, beef), liver (chicken, beef) pork, poultry, seafood, beans, soybeans, green leafy vegetables, peas, dried fruits (raisins, dates, apricots), seaweed, blackstrap molasses, fortified cereals, nuts and seeds.

The iron in meat based foods is easily absorbed than plant based foods. Vegans and vegetarians will need to include a wide variety of high iron plant based foods to ensure adequate iron intake. The heme iron in animals based foods can help absorb the non heme iron found in plant based food increasing its absorption.

Recommended Dietary Allowance


Iron: Recommended Dietary Allowance (RDA) in milligrams (mg/d)


0-6 months

0.27 mg*

7-12 months

11 mg

1-3 years

7 mg

4-8 years

10 mg





Iron: Recommended Dietary Allowance (RDA) in milligrams (mg/d)


9-13 years

8 mg



14-18 years

11 mg



19-30 years

8 mg



31-50 years

8 mg



51+ years

8 mg












9-13 years

8 mg



14-18 years

15 mg

27 mg

10 mg

19-30 years

18 mg

27 mg

9 mg

31-50 years

18 mg

27 mg

9 mg

51+ years

8 mg




*Adequate intake

The tolerable Upper Intake Level (UL) for copper is set at 45 milligrams per day for adults. [28] [29]

Iron Supplementation

Iron is available as tablets, capsules and liquids. There are two main types of iron which are heme and non heme iron. Heme iron can be found in meat whereas the non heme iron is found in plant based food.

Iron supplements are available as ferric and ferrous. Ferrous iron is absorbed by the body than ferric iron and can be found as ferrous sulfate, ferrous fumarate and ferrous gluconate. Other iron supplements include ferric citrate, ferrous salt of gluconic acid and ferrous succinate.

Common side effects from iron supplements includes constipation, diarrhea, nausea, vomiting, heartburn, stomach pain, stomach pain, black or dark-colored stools or urine, or stained teeth.

Some forms of iron have fewer side effects which includes heme iron polypeptides, carbonyl iron, iron amino-acid chelates, and polysaccharide-iron complexes and iron amino acid chelate.

Deficiency symptoms of Iron

One of the most common symptom of iron deficiency is anemia which is diagnosed by checking hemoglobin levels. The normal range for hemoglobin is 13.5 to 17.5g (grams) per dL (decilitre) of blood for men. For women the normal range is 12.0g to 15.5g per dL of blood.

The following are symptoms of an iron deficiency:

  • Fatigue (Extreme / Chronic)
  • Weakness
  • Muscle spasms
  • Dry / brittle hair
  • Brittle nails
  • Pale skin
  • Chest pain
  • Rapid heartbeat
  • Breathlessness / shortness of breath
  • Headache
  • Dizziness/ Light headedness
  • Cold handsand feet
  • Inflamed or sore tongue
  • Unusual cravings for non-food items such soil, clay, chalk etc (pica)
  • Craving and chewing ice (pagophagia)
  • Poor appetite
  • Hearing loss
  • Tinnitus*

*Some studies are showing a link between tinnitus and patients with anemia. [30]

The following are the causes and risk factors associated with iron deficiency:

  • Blood loss
  • Lack of iron in diet
  • Malabsorption
  • Pregnancy
  • Women with heavy menstrual bleeding
  • Frequent blood donation
  • Premature children
  • Vegetarians and vegan diets

Toxicity symptoms of Iron

The reticuloendothelial system helps to break down aged red blood cells and is involved in the regulating iron stores in the body. When iron is not absorbed or recycled appropriately in the body this can lead to iron overload. Overdose of iron is quite rare but possible from extremely high and chronic intake of iron supplements. It can also occur from deficiencies of other key nutrients that help with iron absorption, reduced intake of these nutrients will lead to a build-up of iron. Women of child bearing age can lose some iron through menstruation.

Hemochromatosis is an inherited disorder where the body has too much iron.

The following symptoms and conditions associated with too much iron:

  • Chronic fatigue
  • Weakness
  • Lethargy
  • Abdominal pain
  • Nausea
  • Vomiting
  • Diarrhea
  • Joint pain
  • Osteoarthritis
  • Liver disease (cirrhosis, liver cancer)
  • Diabetes mellitus
  • Loss of sex drive
  • Absent or scanty menstrual periods
  • Early menopause
  • Decrease in body hair
  • Skin color changes (ash gray, bronze or discolored skin tone)
  • Irregular heart rhythm
  • Heart attack or heart failure
  • Impaired memory
  • Mood swings
  • Severe irritability
  • Depression

In addition to hemochromatosis there are many other factors that can cause iron levels to accumulate which includes consuming high amounts of iron containing food, water and supplements and intake of high amounts of other nutrients that help absorb iron such as vitamin C. Age is also another factor as iron can accumulate over time. High amounts of iron can also be stored and accumulated in the body when other nutrients that help absorb iron are too low.

Precautions and warnings

Some forms of iron supplements can interact with certain medications. When taking any medications it is important to discuss with your doctor or other health professional before supplementing with any form of iron.