Anemia is a condition in which you lack enough healthy red blood cells to carry adequate oxygen to your body’s tissues. Having anemia can make you feel tired and weak. There are many forms of anemia, each with its own cause.
Iron deficiency anemia, the most common type of anemia, is caused by having too little iron in your body. To treat iron deficiency anemia, your doctor will likely recommend you take iron supplements and make dietary changes. But how much iron is too much when you have iron deficiency anemia?
What causes iron deficiency anemia?
Your body needs iron to make hemoglobin, a protein in red blood cells. Hemoglobin gives blood its red color. This protein helps red blood cells carry oxygen from your lungs to all parts of your body. If hemoglobin levels drop too low, your body can’t get the oxygen it needs to function properly.
Without adequate iron, your body can’t produce enough hemoglobin for red blood cells. When that happens, oxygen carried in your blood drops to below normal levels, and anemia develops.
Women who menstruate are at higher risk of iron deficiency anemia because of monthly blood loss. Slow, chronic blood loss within your body — such as from a peptic ulcer, a hiatal hernia, a colon polyp or colorectal cancer — can also cause iron deficiency anemia.
How is iron deficiency anemia treated?
Iron deficiency anemia is treated by boosting your iron intake, generally with iron supplements and changes in your diet.
Iron supplements. Your doctor may recommend an iron supplement. Supplements come in tablets, capsules and liquids. Taken on an empty stomach, iron supplements are more easily absorbed by your body. Absorption decreases when taken with food.
The recommended daily amount of iron depends on your age, sex and other factors. However, most adults and children need 8 to 18 milligrams daily. Too much iron can be toxic.
Dietary changes. You may also need to make changes in your diet to increase iron-rich foods, including:
- Meat, poultry and seafood
- Fortified cereals
- Beans, lentils and nuts
- Dark green leafy vegetables, such as spinach
- Dried fruits, such as raisins and apricots
Vitamin C helps your body absorb iron. So foods high in vitamin C, like oranges, strawberries, broccoli and tomatoes, are good choices.
How much iron is too much?
The recommended daily allowance (RDA) for iron is:
- Infants up to 6 months: 0.27 milligrams (mg)
- Babies age 7-12 months: 11 mg
- Children age 1-3 years: 7 mg
- Kids age 4-8 years: 10 mg
- Children age 9-13 years: 8 mg
- Teens age 14-18 years: 11 mg for boys, 15 mg for girls
- Adult men: 8 mg
- Adult women age 19-50 years: 18 mg
- Pregnant women: 27 mg
- Breastfeeding women: 9-10 mg
The tolerable upper intake level (UL) is the maximum amount considered safe to consume daily over the long term without risk of adverse effects. The UL for iron is:
- Infants up to 6 months: 40 mg
- Babies age 7-12 months: 40 mg
- Children age 1-13 years: 40 mg
- Teens age 14-18 years: 45 mg
- Adults: 45 mg
So in general, 65 mg per day would be considered too high for most people aside from pregnant women advised to take that amount by their doctor. Consuming high amounts above the UL increases your risk of iron overload and toxicity.
What are the risks of too much iron?
Iron overload happens when excess iron builds up in your body. Many people genetically predisposed to absorbing higher levels of iron from foods are at risk. Over time, excess iron is deposited in the liver, heart and other organs, which can cause life-threatening damage. Iron toxicity can occur acutely from consuming extremely high amounts of iron over a short time.
Some risks and symptoms of iron overload and toxicity include:
- Gastrointestinal problems – Nausea, vomiting, diarrhea, constipation, belly pain
- Organ damage – Cirrhosis of the liver, irregular heart rhythms, heart failure
- Diabetes -Iron can increase insulin resistance
- Infections – Iron supports growth of bacteria and other germs
- Osteoporosis – Iron overload prevents osteoblasts from forming bone
- Joint problems – Iron deposits can lead to arthritis
- Fatigue and weakness – Anemia from low hemoglobin can occur if iron isn’t incorporated properly into red blood cells
Signs of acute iron toxicity include nausea, vomiting and diarrhea which progresses to bloody stool or even cardiovascular collapse. Extremely high levels of iron intake over a short period of time can be fatal.
Who is at risk of iron overload?
The people at greatest risk of iron overload include:
- Those with hemochromatosis – A genetic iron excess disorder affecting about 1 million Americans
- Frequent blood donors
- People who take high-dose iron supplements
- Those getting repeated blood transfusions for conditions like beta-thalassemia
- People with a diet very high in iron
- Those with other risks and causes of excess iron absorption
Routine screening typically isn’t recommended to look for iron overload in people without risk factors. But those at high risk should have periodic testing for excess iron buildup such as:
- Ferritin blood test to measure iron stored in the body
- Genetic testing for hemochromatosis
- Imaging tests such as MRI to assess iron deposits in organs
Can 65 mg per day help treat iron deficiency anemia?
In certain cases, a temporary high daily dose of iron up to 65 mg per day could be appropriate. This high amount may be recommended by your doctor to help replenish iron stores depleted by anemia. But it’s generally not advised for long-term supplementation.
For chronic iron deficiency anemia, your doctor will typically start you on a conservative dose such as 325 mg per day of ferrous sulfate. That supplies about 65 mg elemental iron. This allows your doctor to monitor your response and symptoms to avoid iron overload.
After your anemia starts improving and your iron levels increase, your doctor will gradually reduce your dose to avoid toxicity. You may be able to decrease to a lower maintenance dose of iron around 45 to 60 mg one to three times per week.
When iron supplements are taken at doses exceeding the UL on a regular basis, iron can accumulate to toxic levels. High iron intake can also inhibit absorption of other essential minerals like zinc and magnesium.
But periodic short-term iron supplementation at 65 mg per day may be warranted to restore normal hemoglobin concentrations in someone with iron deficiency. Your doctor can help determine the appropriate iron dosing for your individual needs.
Who may need higher iron doses?
Certain people with moderate to severe iron deficiency anemia may benefit from higher iron doses for a limited time to improve their condition, including:
- Women with heavy menstrual bleeding or pregnancy
- People with ulcers, cancers or other conditions causing chronic blood loss
- Those who cannot absorb iron properly due to celiac disease or gastric bypass surgery
- People undergoing dialysis who lose blood
Individuals at risk of anemia should have periodic blood work to measure their hemoglobin, ferritin and iron levels. Your doctor can then determine if you need iron supplementation and the appropriate dose and duration based on your test results.
What are the side effects of too much iron?
Some common side effects of taking high doses of iron supplements can include:
- Stomach cramps or pain
- Temporary darkening of stool
Taking iron supplements with food can help reduce gastrointestinal side effects like nausea. Your doctor may recommend taking slow-release iron tablets which are easier to tolerate.
Rarely, people experience hypersensitivity reactions to iron supplements such as itching, rashes, swelling, breathing problems or anaphylaxis. Discontinue iron immediately if you have signs of an allergic reaction.
Are there any interactions with iron supplements?
Iron can interact with several medications. Taking high amounts of supplemental iron should be avoided unless medically necessary and with your doctor’s approval.
Some key interactions to be aware of include:
- Antibiotics – Oral iron absorbs best when taken two hours apart from antibiotics like ciprofloxacin or doxycycline, which can bind iron.
- Antacids – Antacids containing calcium, magnesium or aluminum can inhibit iron absorption and should be taken separately.
- Thyroid medication – Iron may reduce absorption of thyroid hormones.
- Blood pressure and heart medications – Iron can decrease the effects of medications like methyldopa, captopril and losartan.
- Parkinson’s medications – Iron decreases levodopa effectiveness.
- Seizure medications – Iron decreases levels of phenytoin.
Let your doctor know about any medications you take to help determine appropriate iron dosing while minimizing interactions.
What are dietary tips for getting enough iron?
Rather than relying on supplements alone, getting iron daily from whole food sources high in bioavailable iron is ideal. However, those with iron deficiency anemia may still need supplements in addition to dietary iron.
Some tips for getting enough iron in your diet include:
- Eat iron-rich red meats, poultry, seafood, beans, lentils, tofu, spinach, nuts and seeds.
- Eat foods high in vitamin C like citrus fruits, strawberries, tomatoes and broccoli to enhance iron absorption.
- Avoid excess caffeine and calcium supplements with meals, as they can hinder iron absorption.
- Cook foods like tomatoes, spinach and swiss chard to increase iron bioavailability.
- Choose iron-fortified breads, cereals, pastas and rice.
Those following plant-based diets or who avoid red meat may be prone to low iron intake and need a supplement.
What are symptoms of iron deficiency anemia?
Common symptoms of iron deficiency anemia include:
- Fatigue, weakness, low energy
- Pale skin, lips and nail beds
- Shortness of breath, fast heartbeat
- Headache, dizziness
- Swollen or sore tongue
- Strange food cravings like dirt, clay or ice
- Poor concentration and cognition
- Lower immunity and frequent infections
- Restless legs syndrome
- Brittle nails and hair loss
Babies and children with iron deficiency anemia may exhibit poor growth and mental, motor and behavioral delays.
Without treatment, long-term anemia can increase risk of complications like pregnancy problems, an enlarged heart and heart failure.
Should I take an iron supplement?
You may benefit from an iron supplement if:
- You’ve been diagnosed with iron deficiency anemia based on lab testing
- You have heavy menstrual periods, pregnancy or bleeding within your GI tract
- You follow a vegetarian, vegan or restricted diet with marginal iron
- You regularly donate blood
Iron supplementation should only be taken if medically necessary and with monitoring from your healthcare provider. Routine screening blood work helps determine your iron status.
Choose a supplement with ferrous iron like ferrous sulfate, ferrous gluconate or ferrous fumarate. Take on an empty stomach with vitamin C foods or juice to increase absorption.
Suggested supplemental dosing is typically 50-200 mg iron daily. Your doctor will recommend a specific amount based on your deficiency level, cause of anemia and overall health status.
Tips when taking iron supplements
- Take iron with vitamin C and avoid taking with calcium.
- Take iron supplements twice or thrice daily instead of a single large dose to reduce side effects.
- Take iron tablets with meals if it causes an upset stomach.
- Drink plenty of fluids.
- Monitor stool color and consistency.
- Don’t take iron high doses or long term unless directed by your doctor.
- Allow 4-6 weeks to notice improvement in anemia symptoms.
An adequate intake of iron is vital for energy levels, organ function and oxygen delivery throughout your body. But consuming too much iron, especially through high dose supplementation, can be dangerous.
In general, 65 mg per day or higher exceeds the recommended dietary allowance for iron and may lead to excess buildup and adverse effects if taken long term.
However, for those with moderate to severe iron deficiency anemia causing severe fatigue, supplementation at 65 mg for a limited time may help restore iron levels back to normal under medical supervision.
Work with your doctor to identify the appropriate iron dose to meet your needs based on blood work, diet, medical history and response to supplementation. Ensure proper monitoring to achieve the benefits of iron supplementation and avoid toxicity.