Too many iron supplements can poison you - here's how much you should take

• Iron supplements can cause side effects like dizziness, fainting, and hives.
• Too many iron supplements can cause long-term side effects like liver damage and heart disease.
• If you want to take iron supplements, talk to your doctor about finding the proper dosage for you.

When a person isn't getting enough iron, they may experience symptoms such as excessive fatigue, shortness of breath, and anemia.

Taking iron supplements may help alleviate these problems but can also come with its own potential side effects when iron is taken in high doses and in excess of your needs.

Medical term: Iron is an essential mineral that helps your body create red blood cells, and is found in foods, such as dark chocolate, spinach, and beef.

Here's what you need to know about taking iron supplements and how to lower your risk of unpleasant side effects.

Iron supplement side effects

Iron supplements can contain more than 100% of your daily iron needs, which means it can be easy to exceed your upper limit for iron and experience side effects as a result.

General advice: The upper limit for iron is 40 mg for people 13 years or younger and 45 mg for people 14 years or older.

Ingesting too much iron can corrode tissue in the gastrointestinal tract. "Over time, iron can accumulate in the organs, and cause irreversible damage to organs like the liver and brain," says DeMasi.

Initial side effects of iron supplements

• Chills
• Gastrointestinal distress
• Dizziness
• Fainting
• Hives
• Tingling sensation in the feet or hands

Although rare, if you consume too much iron over time it can cause iron toxicity, which can lead to:

• Liver disease
• Brittle bones
• Heart disease

Visit a doctor immediately if you or children in your care experience any side effects from iron supplements.

An iron overdose can be deadly for children. Between 1983 and 2000, 43 children died after ingesting high doses of iron.

"Iron toxicity is extremely dangerous for children and can lead to multi-organ failure or death in severe cases," says DeMasi. "The first signs of toxicity are nausea, vomiting, diarrhea, and stomach pain."

Iron supplement dosage

Before taking an iron supplement, speak with a doctor to determine the proper dosage. Overall, the amount of iron a person should take per day depends on their age and gender:

• Children 1 to 3 years: 7 mg
• Children 4 to 8 years: 10 mg
• Children 9 to 13: 8 mg
• Adolescent males: 11 mg
• Adolescent females: 15 mg
• Adult males: 8 mg
• Adult females: 18 mg
• Pregnant people: 27 mg

According to DeMasi, people who are at a high-risk of iron overdose, and therefore, should not supplement, include those with:

• Hereditary hemochromatosis
• Frequent red blood cell transfusions
• Myelodysplastic syndrome
• Thalassemia
• Sickle cell disease

Most other individuals do not need to take iron supplements. "Individuals who have normal iron and hemoglobin levels and are not pregnant and of child-bearing age do not generally need iron supplements," says Bansari Acharya, a registered dietitian-nutritionist.

General advice: If you think you may have an iron deficiency or are considering taking iron supplements, reach out to your doctor. They can run a hemoglobin test to diagnose you and help you find the proper dosage.

Iron supplements are available in many forms, including:

• Powder
• Chewable tablet
• Capsule
• Extended-release
• Liquid
• Syrup

Tips for taking iron supplements

The body does not absorb iron as well if it's coming from supplements. However, there are a few ways you can improve your body's ability to absorb iron. According to DeMasi and Acharya, these include:

• Eat more vitamin C-rich foods like citrus fruits, strawberries, bell peppers, and broccoli.
• Avoid consuming food or beverages high in calcium, like milk or yogurt when you take supplements, as they can limit iron absorption.
• Take iron supplements one hour before a meal or two hours after since it's best absorbed on an empty stomach.

The form of iron supplements you take can also help mitigate side effects. According to DeMasi, some people find liquid iron and slow-release iron cause fewer gastrointestinal side effects, since they are more readily absorbed.

Insider's takeaway

Iron supplements can lead to side effects such as gastrointestinal distress and fainting. If you continue to supplement with much more iron than you need, you may experience iron toxicity, which can lead to brittle bones or liver disease.

Unless you are in a high-risk group or have low iron levels, iron supplementation is usually unnecessary.

If you are considering taking iron supplements, speak with your doctor first as they can help you determine the correct dosage.