Iron is an important mineral that makes up a major part of our blood in the form of haemoglobin. Through haemoglobin, iron becomes a crucial nutrient facilitating transport of oxygen to various body tissues, however, it is also essential in the production and functioning of various metabolic enzymes and for maintaining a healthy immune system. It is further needed for the growth and development of the foetus and hence iron supplements are usually prescribed to pregnant women.

Despite all these functions, excess iron could be toxic to the body and can increase the risk of various diseases including liver and heart ailments. Thus, it is essential to maintain a balance of iron in the body while making sure that you take your daily recommended dosage.

But what exactly is that dosage? And how can you reach your daily recommended iron requirements? You’ll find the answer in this article along with the dietary sources of iron and its role in maintaining body functions.

  1. Recommended daily allowance of iron: How much iron to include per day
  2. Iron rich foods: fruits, vegetables, meat and other sources
  3. Iron benefits and uses
  4. Iron side-effects

The daily recommended allowance for iron depends on your age, weight, height and nutritional status.

Following is a table mentioning the standard RDA of iron for non-vegetarians as per the NIH. The RDA for vegetarians is about 1.8 times more than that required by non-vegetarians as animal-based iron is more readily available to the body than plant-based iron. The former also increases the absorption of plant-based iron.

Age Men Women
Up to 6 months 0.27 mg 0.27 mg
7 months to 1 year 11 mg 11 mg
1 to 3 years 7 mg 7 mg
4 to 8 years 10 mg 10 mg
9 years to teenage 8 mg 8 mg
14 to 18 years 11 mg 15 mg
Adult dosage (up to 50 years) 8 mg 18 mg*
Dosage above 50 years of age 8 mg 8 mg
*The daily recommended dosage for pregnant women is 27mg, and for women who are breastfeeding, it is 9mg.

Now you have some rough idea about the recommended dietary intake of iron according to your age, let us move on to how you can obtain this iron from your diet.

Dietary iron is classified into two types:

  • Heme iron: Obtained from animal sources like meat, poultry, chicken and seafood. It is readily available for absorption.
  • Non-heme iron: Obtained from plant-based sources like spinach, pulses and fortified grains. Some amount of non-heme iron is also present in meat and animal products and most iron-based supplements are made of this type of iron. Non-heme iron is not easily available to the body as it needs processing before it can be taken up from the intestines.

Iron absorption may further be reduced if it is taken along with calcium, milk, coffee, tea and eggs.

Here is a list of foods that can assist you in reaching your daily iron requirement with ease.

  • Dark chocolate (45-69%)
  • Leafy greens like Spinach, broccoli and asparagus
  • Barley
  • White beans
  • Tofu
  • Lentils
  • Bulgur
  • Kidney beans, boiled chickpeas and black beans
  • Vegetables like potato and cabbage
  • Fruits such as apricots, tomato, beets and blueberries
  • Roasted chicken
  • Seafood like sardines, oysters and tuna
  • Fortified cereals

Iron supplements are rarely needed, since, they have been found to increase the risk of gastric ulcers and inflammation. However, pregnant women and anaemic individuals are prescribed iron supplements, to be taken under the supervision of a doctor.

Iron is a crucial mineral required for various metabolic functions, most important of that is oxygen transport in the form of haemoglobin. This section covers all the functions that iron performs in your body and just why is it important to take enough iron.

Iron forms haemoglobin

A major portion of the iron is present in our body inside RBCs, as heme protein, haemoglobin. Each haemoglobin molecule has about 4 iron centres with a protein chain and single haemoglobin can thus bind to about 4 oxygen molecules.

A different compound present in muscles and which helps in storage and absorption of iron in the muscle tissue is myoglobin, though, it contains only one iron molecule each. Together, these proteins ensure that oxygen travels from your lungs to your body organs via blood.

Reduction in haemoglobin, iron or RBCs would thus lead to anaemia which is manifested in the form of symptoms such as fatigue, exhaustion, headache, shortness of breath, nausea and discolouration of the oral mucosa.

Iron for energy

Haemoglobin production and oxygen transport may be the first and most important function of iron in our body. But, it has various other functions that are needed to maintain cellular metabolism including energy generation and DNA repair. Bet you never thought your daily green veggies or pulses are so important to your body cells. Iron is converted to FE-S clusters and stored as ferritin in the body. These FE-S clusters aid in the regulation of enzyme, protein function and expression of genes. By helping maintain and regulate DNA synthesis and repair, iron helps you age gracefully.

Iron for hair loss prevention

Iron has a central role in hair growth since it is important for carrying out the various processes inside the hair follicle. Quite obviously, a deficiency in iron would negatively affect hair growth. Research evidence indicates that low levels of ferritin (> or equal to 30 ng/ml) can increase hair loss in women which is independent of any inflammation or skin condition. In a recent study, lack of iron was found to be the cause of female pattern hair loss, especially in premenopausal women.  This may be because premenopausal women lose some of the iron during menstruation every month.

According to a case study mentioned in the Annals of Dermatology, ferrous sulphate was found to be useful for reverting premature hair greying in an Asian male in his 20s.

So, it is important to take the daily dose of iron and keep your hair looking longer and healthier.

Iron benefits during pregnancy

Iron deficiency and anaemia are two of the most feared conditions during pregnancy. Low haemoglobin levels in a gestating woman may remain asymptomatic for long but can adversely affect foetal growth and birthweight. This is because a pregnant woman needs about 1000 to 1200 mg of iron per day. About ⅓ of this is maternal demand and rest is needed for foetal growth and haematopoiesis (formation of blood). The demand for iron increases progressively from first to the third trimester, however, a deficiency in the first trimester is most often the cause of birth defects as iron is needed for the formation of the neural tube.

Babies born to an anaemic mother may also show signs of anaemia and have been found to exhibit lowered memory and cognition even in the later stages of life. Despite this, foetal defects and miscarriage were found to be only caused when blood haemoglobin levels fall down below 10g and it is not important to take iron supplements if your haemoglobin levels are normal.

It is suggested that you refer to a doctor to know if you need iron supplements in the first place.

Iron for improving memory

Just like an iron deficiency causes impairment in neonatal brain functions, it can lead to memory defects and reduced cognition in adults and older children too. This is because iron is required to produce energy via various cellular processes and this energy is needed to maintain and regulate neuron function and structure. Important functions of iron in the brain include:

  • DNA synthesis
  • Myelin synthesis
  • Synthesis of various neurotransmitters

Any imbalance in iron levels leads to the formation of harmful hydroxyl radicals which in turn increases the oxidative stress and speeds up the ageing process in the brain. Improper iron distribution and accumulation is one of the diagnostic features of neurodegenerative diseases such as Alzheimer's and Parkinson’s.

It is important that you don’t miss out on your dietary iron to keep your brain healthy and reduce the risk of neurodegeneration.

(Read more: How to improve brain power)

Iron for immunity

Iron is important to carry out various cellular functions in humans but they are as important to microbial cells and hence, there is a constant tug of war between host cells and pathogenic bacteria to obtain iron. This also forms one of the major factors of immunity and host defence or alternatively, infections.

Human body maintains constant homeostasis of iron to perform its everyday functions and to avoid excess.

Iron is preserved inside the haemoglobin ring to keep infectious microbes from reaching in and these microbes, in turn, target and lyse RBCs or compete with normal body proteins which scavenge off these lysed heme protein molecules.

On the other side, iron is needed to mediate a proper immune response by the host body.

  • Iron is responsible for mediating cytokine production (a type of immune system protein) in macrophages.
  • Lactoferrin is yet another iron compound released by neutrophils to fight infection.
  • Iron is used by the immune system to inhibit microbial growth since it also has some toxic effects on living cells.

Iron overload is further responsible for increased oxidative stress which degrades metabolism, and leads to a weaker immune system, thus leading to an increased chance of acquiring infections.

Needless to say, it is important that you maintain a healthy balance of iron in your body by not taking excessive supplements until needed.

(Read more: How to improve immunity)

After being acquainted with all the benefits that iron has for your body, and knowing it’s daily requirements, it is quite clear that acquiring your daily iron fill is quite easy through diet and supplements are rarely needed. Though it is important that you also know about the downsides of excess iron consumption since that is not as uncommon as it seems.

Let us have a look at the side effects of iron:

  • Gastric ulcers and inflammation have been found to increase due to regular consumption of iron supplements.
  • It may also cause constipation and diarrhoea and stomach pain.
  • Nausea and vomiting are yet another side effect of consuming excess iron.
  • Black stools are one of the most common symptoms of iron supplements.
  • Severe iron deficiency can cause multiple organ failure, convulsions, coma and death.
  • It increases the risk of colorectal cancer.
  • A big part of the body’s iron is stored inside the liver and liver plays an important role in iron metabolism and homeostasis. Consequently, an increase in iron levels has been associated with liver damage, cirrhosis and chronic liver diseases.
  • Iron may interfere with certain medications like proton pump inhibitors and levothyroxine.

You already know the recommended daily uptake of iron. However, the tolerable limit also varies as per gender, age and physiology. As per the NIH, following are the upper limits of iron toleration ranging across gender and age.

Age Men Women
   mg 40 mg
7 months to 1 year 40 mg 40 mg
1 to 3 years 40 mg 40 mg
4 to 8 years 40 mg 40 mg
9 years to teenage 40 mg 40 mg
14 to 18 years 45 mg 45 mg
Adult dosage (up to 50 years) 45 mg 45 mg*

*Upper limit of daily iron dosage is the same for women who are pregnant or breastfeeding.

Medicines / Products that contain Iron


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  2. National Institutes of Health; Office of Dietary Supplements. [Internet]. U.S. Department of Health & Human Services; Iron.
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  13. [Internet]. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006. Pregnancy and birth: Do all pregnant women need to take iron supplements?. 2009 Dec 22 [Updated 2018 Mar 22].
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  15. School of Health Sciences. Nutrition in Wound Healing.University of Nottingham, UK
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