Iron Supplements For Anemia: Types, Benefits, And Risk

Iron is an important mineral. It plays a significant role in producing red blood cells, which transport oxygen from the lungs to the rest of the body.

Iron deficiency occurs when there isn’t enough iron in the body. It leads to anemia, a condition characterized by low red blood cell levels. Iron deficiency anemia reduces oxygen flow to your organs and tissues.

Iron deficiency is a common nutritional disorder affecting 25% of people worldwide.¹

Increasing an individual’s intake of iron-rich foods may help manage anemia in some cases. Iron supplements are often used.

This article reviews the different types of iron supplements and their relative benefits and risks.

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Benefits of iron supplements for anemia

Food is a natural source of iron, and many grain-based foods, such as breakfast cereals, are fortified with iron. Other good iron sources include oysters, white beans, beef liver, lentils, spinach, and tofu.²

Being diagnosed with iron deficiency anemia means you’re not getting enough iron through your diet to meet your nutritional needs.

You may be able to address this problem by consuming more iron-rich foods. However, for many people, diet alone isn’t enough. Although paying attention to eating more iron may help prevent iron deficiency anemia, those who already have it will likely need to take in extra iron through iron supplementation.

Iron supplements may come in the form of a high-dose liquid or tablet that you swallow. It can also be supplemented intravenously (IV), where it’s injected directly into your bloodstream.

You can get iron pills for anemia and other formulations over the counter, but it’s best to consult a doctor before you start taking them. This is because anemia can be a sign of a serious medical problem.

Iron deficiency anemia isn’t always caused by eating too little iron. Bleeding somewhere in the body could cause the condition, which may indicate a serious disease like colon cancer.

It’s important to consult a doctor for evaluation before you start taking iron supplements to rule out serious medical conditions.

Types of iron supplements for anemia

In general, there are two main types of iron supplements: oral and intravenous.³

Oral iron supplements

Oral iron supplements are commonly used to treat anemia. They come in different forms, such as tablets, capsules, and drops.

Various forms of iron may be used in oral iron supplements, including:

  • Ferrous fumarate

  • Ferrous gluconate

  • Ferrous sulfate

  • Ferric maltol

  • Polysaccharide iron complex

Oral iron supplements can cause digestive side effects, including constipation, nausea, decreased appetite, and diarrhea.

Some oral iron supplements are extended-release. This means the iron is released slowly into your digestive tract instead of all at once. Extended-release iron supplements may cause fewer digestive side effects.

Intravenous iron supplements

Some people may need to take iron supplements through an IV. This method of taking iron supplements may be recommended if

  • Oral iron supplements cause you bothersome side effects

  • You already have significant nausea and vomiting (because you’re pregnant, for example)

  • Your digestive system has trouble absorbing iron — this may occur if you have a gastric bypass, a digestive condition like celiac disease, or a chronic inflammatory disease like lupus

IV iron supplementation can still cause digestive issues like nausea. It can also cause serious allergic reactions in some people.

Receiving IV iron is generally painful, and some of the iron can escape from the vein and permanently stain the skin. IV supplementation is also more costly than using oral iron supplements for anemia.

What supplements should you take for anemia?

Before taking any type of supplement for anemia, it’s important to consult with your doctor.

Anemia has several potential causes and can sometimes indicate a serious underlying medical condition. You will need a medical evaluation to determine the cause of your anemia before taking supplements to treat it.

You can take various supplements to help treat anemia.

Iron supplements

Iron is typically given as a treatment for iron deficiency anemia. This condition can result from inadequate dietary iron intake, blood loss, chronic inflammation, or a condition that makes it difficult for the body to absorb iron from the digestive tract.⁴

B vitamin supplements

Deficiencies of certain vitamins can also lead to anemia. These include folate (vitamin B9), vitamin B12, and vitamin B6.⁵

All three of these vitamins are available as oral supplements or injections. The oral versions are available over the counter, while the injectable medications require a prescription. 

Iron supplement dosage

The required iron dosage varies depending on sex, age, and whether or not you are pregnant or breastfeeding.

Below are the recommended dietary allowances for iron for people aged 14+ in different groups.⁶

Note that these recommended dietary allowances are guidelines. It’s very important to discuss iron supplementation with a medical professional. Depending on your circumstances, they will advise you on how much iron you need to supplement.

Iron-rich diet for iron deficiency anemia

Iron is an essential mineral that comes naturally from food. Not everyone has to rely on supplementation to get the iron they need. People with mild iron deficiency anemia may be able to get enough iron from dietary sources.

Be sure to talk with your doctor about your recommended treatment plan. People with more severe cases of iron deficiency anemia may need supplementation.

Heme and non-heme are the two forms of iron. You can only get heme iron from animal products, and it’s more easily absorbed by the digestive tract. Non-heme iron can be found in a variety of plant foods.

Below are iron-rich foods that may help you ensure that you’re getting enough iron.

  • Beef, pork, chicken, and turkey

  • Legumes, like beans, soybeans, chickpeas, and lentils

  • Seafood, such as oysters and sardines

  • Dark green leafy vegetables, like spinach (spinach is also rich in vitamin C, which boosts iron absorption)

  • Iron-fortified grain products, like cereals, pasta, and bread

  • Dried fruits, such as raisins

  • Organ meats, such as liver (also high in B vitamins, including vitamin B12)

  • Quinoa

  • Pumpkin seeds

  • Broccoli

  • Tofu

  • Dark chocolate

Side effects of anemia supplements

Iron supplements can often manage anemia effectively if taken in the recommended doses. However, in some cases, people taking anemia supplements may experience adverse effects, such as:

  • Nausea

  • Diarrhea

  • Flatulence

  • Constipation

These side effects may disappear once your body has adjusted to the iron supplements. However, if these side effects persist or you have concerns about them, you should speak to a healthcare professional.

Switching to an extended-release oral iron supplement may help with your side effects, or your doctor may prescribe IV iron instead.

How long does it take for iron supplements to take effect?

The factors below can affect how quickly your red blood cell count returns to normal once you start taking iron supplements.

  1. The severity of anemia. If you are severely anemic, your red blood cell count will take longer to return to normal.

  2. Supplement dosage. Iron supplements come in different strengths. Supplements with higher strengths may take effect sooner than those with low strengths.

  3. Supplement absorption rate. Your body can absorb a limited amount of nutrients at any one time. Various factors affect a supplement’s absorption rate, including stomach acidity, other foods and supplements you consume alongside iron, and the type of supplement you’re taking. Taking iron every other day may boost absorption compared to taking it every day.⁷

For people with relatively mild anemia, red blood cell counts often return to normal within four weeks of starting iron supplements. However, it may take significantly longer for those with more severe anemia.⁸

Many patients need to take iron for months. It’s often recommended to continue taking iron for some time after your red blood cell counts return to normal. This is to help replenish your body’s iron stores.

For people taking IV iron, red blood cell counts should return to normal within six weeks.

The lowdown

Anemia is a condition characterized by low levels of red blood cells in the body. Red blood cells carry oxygen to your tissues, and not having enough of them can affect your whole body.

Iron is a nutrient that is needed to make red blood cells. You can get iron from foods, so consuming more iron-rich foods may help if you have been diagnosed with iron-deficiency anemia. Iron-rich foods include red meat, legumes, seafood, and dark green leafy vegetables.

However, doctors may recommend iron supplements in some cases. Iron supplements can either be taken orally or given intravenously.

Iron supplements often cause digestive side effects, like nausea, constipation, and diarrhea. If you experience these effects, continue to take your recommended dose and visit your doctor to discuss the problem. They may recommend changing your dose or supplement.

Frequently asked questions

How is anemia diagnosed?

To diagnose anemia, your doctor may ask about your symptoms and any risk factors you have. Diagnosis typically involves a blood test. Your doctor may order tests of your complete blood count (which counts the numbers of various types of cells in your blood), hemoglobin, and/or hematocrit.

To determine the cause of anemia, your doctor may order additional tests, including blood tests, urine tests, a bone marrow biopsy, a colonoscopy, and/or an endoscopy.

How is anemia treated?

Treatment for anemia depends on the cause. For example, in cases of iron deficiency anemia, treatment may involve addressing any sources of bleeding, such as a disease in the digestive tract.

Next, you will need to restore your body’s iron levels. This is usually accomplished with iron supplements. You can take iron pills for anemia or a high-dose liquid. Alternatively, you’ll receive supplemental iron through an IV.

Can you treat anemia without iron supplements?

In mild cases of iron deficiency anemia, it may be possible to build your iron stores back up by eating more iron-rich foods rather than taking supplements. Red meat, legumes, and seafood are good sources of iron.

Iron supplements are recommended in more severe cases to restore oxygen supply to your body’s tissues.

Many types of anemia are not caused by iron deficiency, and other treatment methods may be used.

How do you take iron supplements for anemia?

Follow your doctor’s or pharmacist’s recommendations for taking iron supplements.

In general, it’s recommended to take iron supplements without food.

You are advised not to take iron supplements with any source of calcium (such as dairy products, antacids, or calcium supplements) because calcium can interfere with iron absorption.

Caffeine and certain medications can also interfere with iron absorption. However, vitamin C may help enhance iron absorption, so many people take iron supplements with orange juice.

Can you take too much iron?

While having too little iron can cause health problems, having too much iron can also pose risks.⁹

Excess iron builds up in various organs, including the pancreas, liver, and heart. This can cause severe organ damage. An inherited condition called hemochromatosis can cause this, but taking too much iron through supplements can have the same effect.

Seek professional medical advice as soon as possible if you suspect you have taken too much iron.

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