Too much or too little iron in your diet can lead to health issues like liver problems, iron-deficiency anemia, and heart damage.
Naturally, you may wonder just how much iron is an ideal amount. Here’s where it gets a little tricky.
While generalized recommendations offer some guidance, your specific iron needs are influenced by many factors, including age, sex, and diet.
This article discusses how much iron you may need, factors impacting those needs, and how to tell if you’re not getting the right amount.
What is iron and why is it important?
Iron is a nutrient that plays a vital role in oxygen transport. It binds to hemoglobin, a special protein, and helps it carry red blood cells from your lungs to other tissues in your body.
Iron is naturally available in the foods you eat, and there are two main types — heme and nonheme iron.
The term “heme” is derived from a Greek word that loosely translates to “blood.” This type of iron comes from animal protein, such as poultry, fish, and beef.
On the other hand, nonheme iron comes from plant sources, including legumes, leafy greens, and nuts.
Heme iron is easiest for your body to absorb and is 14–18% bioavailable in mixed diets. Nonheme iron, the iron source in vegetarian diets, has a bioavailability of 5–12%.
Summary: Iron is an essential nutrient. Two types of iron are found in the human diet — heme iron comes from animal protein, while nonheme iron comes from plants. Your body can absorb heme iron more readily.
Iron needs vary depending on sex and age.
Infants and children (to age 13)
Boys’ and girls’ iron needs from infancy and into late childhood are identical. This is because menstruation does not typically begin before age 13.
Newborn babies need the least amount of iron from their diet. They’re born with a store of iron, absorbed from their mother’s blood while in the womb.
The adequate intake for infants from birth and up to the first 6 months is 0.27 mg daily. The adequate intake is simply an average of what is normally consumed by healthy, breastfed infants. Thus, their needs are met through breastfeeding alone or from a formula.
Babies who spent less time in the womb, such as premature babies, need more iron than full-term infants. The same holds for babies with low birth weight.
However, adequate intakes for premature and low-birthweight infants have not been established. In these instances, it’s best to talk to your healthcare provider about your baby’s iron needs.
Into the second 6 months of life, 7- to 12-month-old infants should get significantly more iron, at 11 mg daily, according to the recommended dietary allowance.
This is due to their rapidly developing brains and blood supply needs. Iron is crucial to proper brain development.
As they age into toddlers, or between the ages of 1 and 3, your child’s iron needs are 7 mg daily. Then, from ages 4 to 8, boys and girls should get 10 mg of iron from their diet each day.
In later childhood, from 9 to 13 years, kids need 8 mg of dietary iron daily.
Between the ages of 14 and 18, boys’ recommended dietary allowance for iron is 11 mg. This helps supports growth spurts common at this age.
Teenaged girls need more iron than boys their age — 15 mg daily. This is because they need to not only support growth but also compensate for iron lost through menstruation.
Significant physical and brain growth has slowed by age 19. Thus, men’s iron needs stabilize during adulthood.
Whether 19 or 99, younger and older adult men alike need 8 mg daily to maintain their health.
Highly-active men, such as endurance athletes, may need more than this amount, as your body loses iron through sweat.
The typical adult — male or female — stores between 1–3 grams of iron in their body. Simultaneously, about 1 mg is lost daily due to the shedding of the skin and mucosal surfaces like that lining your gut.
Suggested read: B-complex vitamins: Benefits, side effects and dosage
Women who menstruate need more iron. This is because blood contains about 70% of your body’s iron. At the beginning of the menstrual cycle, the body loses about 2 mg daily, as blood is shed from the lining of the uterus.
Between 19 and 50 years of age, women need 18 mg of iron per day. Female athletes have higher needs to account for the amount of iron lost to sweating.
Older women, ages 51 and older, need 8 mg of iron per day. This accounts for the onset of menopause, which is marked by the end of menstruation.
Transgender teens and adults
Though official recommendations are unavailable, adult transgender men who have medically transitioned are often advised to adhere to the iron recommendation of 8 mg per day for cisgender men once menstruation has ceased.
Adult transgender women who have medically transitioned should also get 8 mg daily.
If you haven’t taken hormones or undergone other steps to medically transition, your iron needs may differ.
Likewise, the iron needs of teen transgender folks — both those who have medically transitioned and those who have not — may differ from adult needs.
Therefore, if you’re transgender, it’s best to discuss your iron needs with your healthcare provider. They can help determine the correct dosage for your individual needs.
Iron needs during pregnancy and lactation
During pregnancy, your iron needs rise to 27 mg to support the needs of the fetus.
If you’re predominantly breastfeeding, your iron needs drop from levels needed during pregnancy. In these circumstances, women need 9–10 mg of iron, depending on their age. These levels accommodate the woman’s own needs, as well as the baby’s.
Lactating produces a hormone called prolactin, which may inhibit menstruation. Therefore, these lower recommendations assume that iron is not being lost through menstruation.
Iron needs overview
Here’s a visual summary of daily iron needs according to biological sex and age:
Suggested read: How much vitamin C should you take per day?
- Birth to 6 fonths: 0.27 mg/day
- 7-12 months: 11 mg/day
- 1-3 years: 7 mg/day
- 4-8 years: 10 mg/day
- 9-13 years: 8 mg/day
- 14-18 years: 15 mg/day
- 19-30 years: 18 mg/day
- 31-50 years: 18 mg/day
- 51+ years: 8 mg/day
- Pregnancy: 27 mg/day
- Lactation (younger than 18 years): 10 mg/day
- Lactation (19-50 years): 9 mg/day
- Birth to 6 fonths: 0.27 mg/day
- 7-12 months: 11 mg/day
- 1-3 years: 7 mg/day
- 4-8 years: 10 mg/day
- 9-13 years: 8 mg/day
- 14-18 years: 11 mg/day
- 19-30 years: 8 mg/day
- 31-50 years: 8 mg/day
- 51+ years: 8 mg/day
Summary: Iron needs vary according to age and sex. Infants, children, and teens have a broad range of iron needs. Adult men’s needs are more stable, while women’s fluctuate according to age and whether or not they’re pregnant or nursing.
Getting just the right amount
Interestingly, the way in which your body metabolizes iron is unique, as it doesn’t excrete this mineral and instead recycles and retains it.
Thus, getting too much or too little iron can be a concern.
Too much iron
Iron is concentrated in human blood. Because of this, people who receive regular blood transfusions, such as those in cancer therapy, may be at risk of getting too much iron.
This condition is known as iron overload. It happens because your body cannot rid itself of its iron stores before being supplied with more from the blood transfusion.
While iron is necessary, too much could be toxic and damage your liver, heart, and other vital organs.
However, iron overload is not a concern when your iron comes from diet alone — unless you have a condition like hemochromatosis, which causes increased absorption of iron in your digestive tract.
Keep in mind that the tolerable upper intake level — the highest amount you can safely consume — is 40–45 mg per day for iron, depending on your sex and age.
Not enough iron
Pregnant women, infants, endurance athletes, and teenage girls are most at risk of iron deficiency.
Babies who are not getting adequate iron may be slow to gain weight. They may also seem pale, tired, lack appetite, get sick more often, and be irritable.
Suggested read: Fish oil dosage: How much should you take per day?
Iron deficiency can also lead to poor concentration, a short attention span, and negative effects on children’s academic performance.
Not getting enough iron could also cause iron-deficiency anemia, the most common nutritional deficiency in the world.
If you have this condition, your body doesn’t have enough iron to form new red blood cells. It’s typically caused by either a diet deficient in iron or by chronic blood loss.
Symptoms to look for
If you’re not getting enough iron, you may feel weak, fatigued, and bruise easily. You may be pale, feel anxious, or have cold hands and feet or brittle nails. You might also experience abnormal cravings, such as a desire to eat soil — a condition known as pica.
Alternately, if you experience joint pain or a change in skin tone, or if you get sick easily, you might be getting too much iron. You are especially at risk if you regularly receive blood transfusions.
If you’re concerned that you’re getting too much or too little iron, be sure to speak to your healthcare provider.
Summary: Getting too much iron may be a concern for people who receive blood transfusions regularly and may result in toxicity. Low iron intake could lead to iron-deficiency anemia.
Other circumstances that impact iron needs
Other circumstances may affect your iron needs, such as dietary restrictions, medications, and health conditions.
While the Western diet typically contains 7 mg of iron for every 1,000 calories, only an estimated 1–2 mg of iron will be absorbed by your body.
People who follow a vegan diet need 1.8 times the recommended dietary allowance, compared with those who eat meat. This is because nonheme iron is not as readily available to your body as heme iron.
For example, a healthy adult woman between the ages of 19 and 50 who eats animal protein regularly may need 18 mg of iron daily. If she follows a vegan diet instead, she’ll need about 32 mg.
Some medications may deplete or interact with iron. This can alter your iron needs.
For instance, iron supplements interfere with the effectiveness of Levodopa, a common medication for the treatment of Parkinson’s disease, as well as Levothyroxine, used to treat thyroid cancer and goiter.
Proton pump inhibitors, such as those used to treat gastric reflux, adversely affect how iron is absorbed. Taking these consistently for several years may increase your iron needs.
If you’re taking any of these medications, speak to your healthcare provider to determine your optimal iron needs.
Ongoing health conditions
Certain health conditions may affect your iron needs.
For instance, if you experience gastrointestinal bleeding from ulcers or cancer, the added blood loss may mean you need extra iron. Getting kidney dialysis regularly also drives up your iron needs.
What’s more, being deficient in vitamin A may interfere with your ability to efficiently absorb iron. This may increase your iron needs.
Talk to your health provider if you feel you may not be getting adequate iron from your diet.
Summary: Medications, health conditions, and any dietary restrictions can impact how much iron you should be getting each day. For instance, vegans and vegetarians should get 1.8 times the recommended dietary allowances for iron each day.
How to get enough iron in your diet
Heme iron is the richest and most efficiently absorbed type. It’s most concentrated in shellfish, organ meats, poultry, and eggs.
Rich vegetarian sources of iron include chickpeas, quinoa, seeds, beans, fortified cereals, and leafy greens.
Plus, dark chocolate contains a surprising amount of iron, at 19% of the daily value per 1-ounce (28-gram) serving.
Keep in mind that recommended dietary allowances are specific to sex and age groups, while product labels generally refer to the daily value. The daily value is a fixed number, independent of sex or age. The established daily value for iron across biological sexes and ages is 18 mg.
What’s more, what you eat alongside iron-rich foods matters. Pairing your high-iron foods with foods rich in vitamin C like fruits and vegetables increases iron absorption.
Suggested read: 7 common nutrient deficiencies
For instance, drinking orange juice with a plate of eggs increases your body’s absorption of the iron in eggs.
Conversely, accompanying your high-iron foods with calcium-rich foods, such as drinking milk with a plate of eggs, inhibits iron absorption. Therefore, it’s best to consume calcium-rich foods at a separate time.
If you believe you need to supplement your diet, commercial iron supplements deliver iron in the form of ferrous fumarate, ferrous sulfate, and ferrous gluconate.
These contain varying amounts of elemental iron. Elemental iron refers to the amount of iron in a supplement that your body can absorb. Ferrous fumarate delivers the most, at 33%, and ferrous gluconate the least, at 12%.
Supplementing with iron may cause constipation and intestinal discomfort, so it’s best to get iron from foods whenever possible.
It’s typically recommended that children or infants not consume iron supplements and instead get iron from their diet. If your child was born prematurely or with low birth weight, speak to your healthcare provider about their iron needs.
Multivitamins typically deliver 18 mg of iron or 100% of the daily value. Supplements containing only iron may pack around 360% of the daily value. Getting more than 45 mg of iron daily is associated with intestinal distress and constipation in adults.
Summary: Regularly eating iron-rich foods helps keep your iron levels healthy and pairing them with foods rich in vitamin C enhances iron absorption. If you feel like you’re getting too much or too little iron, consult a health professional.
Iron needs are most stable in men. Women’s needs fluctuate according to age and whether or not they’re pregnant or nursing.
Your ideal iron intake is also affected by other factors, such as dietary restrictions, ongoing health issues, and whether or not you’re taking certain medications.
Heme iron is most readily absorbed by your body and comes from animal protein. Pairing iron with vitamin C helps your body absorb it best.
Suggested read: Does too much vitamin C cause side effects?
Keep in mind that if you rely solely on nonheme (plant-based) iron, you need to consume more iron overall.
Getting too much iron could lead to iron overload, while not getting enough may lead to iron deficiency anemia.
Talk to your healthcare provider if you have concerns about how much iron you’re getting.