Iron deficiency is one of the most common nutrition problems in the world. Iron helps your blood carry oxygen, so when levels run low you can feel tired, weak and unable to concentrate. This guide explains the symptoms of iron deficiency, who is most at risk, how much iron you need each day and which foods help, using guidance from the NIH Office of Dietary Supplements.
Short-term low iron intake usually causes no obvious symptoms. Problems appear when the shortage continues long enough to cause iron deficiency anemia, so knowing the early signs and risk factors matters.
Common Symptoms of Iron Deficiency
According to the NIH, iron deficiency anemia can cause:
- Weakness, tiredness and lack of energy
- Problems with concentration and memory
- Stomach upset
- Reduced ability to fight infections
- Reduced ability to work, exercise and control body temperature
In infants and children, low iron can also lead to learning difficulties. These symptoms are not specific to iron deficiency, so a blood test ordered by a doctor is the only reliable way to confirm it.
Who Is at Higher Risk?
Vegetarians who do not eat meat, poultry or seafood may need almost twice as much iron as the standard recommendation, because iron from plant foods is absorbed less easily.
- Teen girls and women with heavy periods
- Pregnant women and pregnant teens
- Infants, especially premature or low-birth-weight babies
- Frequent blood donors
- People with cancer, heart failure or digestive disorders that affect absorption
- People who do not eat meat, poultry or seafood
How Much Iron Do You Need Each Day?
The NIH lists these average daily recommended amounts:
- Children 1 to 3 years: 7 mg
- Children 4 to 8 years: 10 mg
- Children 9 to 13 years: 8 mg
- Teen boys 14 to 18 years: 11 mg; teen girls 14 to 18 years: 15 mg
- Adult men 19 to 50 years: 8 mg; adult women 19 to 50 years: 18 mg
- Adults 51 years and older: 8 mg
- Pregnant women: 27 mg
- Breastfeeding women: 9 mg (10 mg for teens)
The tolerable upper intake level for adults is 45 mg a day from food and supplements together. A doctor may prescribe more than this to treat a diagnosed deficiency.
Best Food Sources of Iron
Eating vitamin C rich foods such as citrus fruits, tomatoes, sweet peppers, broccoli and strawberries along with plant-based iron helps your body absorb more of it.
- Lean meat, seafood and poultry
- Iron-fortified breakfast cereals and breads
- Lentils (dal), white beans, kidney beans (rajma) and peas
- Spinach and other leafy greens
- Nuts and dried fruits such as raisins
Can You Take Too Much Iron?
Yes. High doses of iron can cause stomach upset, constipation, nausea, abdominal pain, vomiting and diarrhea, and extremely high doses can be dangerous. People with hereditary hemochromatosis should avoid iron and vitamin C supplements. For this reason, take iron tablets only when a doctor advises, and keep them away from children.
When to See a Doctor
- You feel constantly tired or weak without a clear reason
- You have very heavy or long periods
- You are pregnant or planning a pregnancy
- You notice black stools or other signs of blood loss
A simple blood test can check your hemoglobin and iron stores, and your doctor can then recommend the right diet changes or treatment.
Helpful Video
Frequently Asked Questions
What are the first signs of iron deficiency?
Early iron deficiency may cause no symptoms. As it progresses to anemia, common signs include tiredness, weakness, poor concentration and reduced stamina.
How much iron does a woman need per day?
Women aged 19 to 50 need about 18 mg of iron a day, rising to 27 mg during pregnancy, according to the NIH.
Which foods are rich in iron?
Lean meat, seafood, poultry, fortified cereals, lentils, beans, spinach, nuts and raisins are good sources. Pair plant sources with vitamin C foods to improve absorption.
Should I take iron supplements without a prescription?
It is better not to. Excess iron can cause side effects and can be harmful, so confirm a deficiency with a blood test and follow your doctor advice.
Can vegetarians get enough iron?
Yes, with planning. Vegetarians may need almost twice the standard amount, so include lentils, beans, greens, nuts and fortified foods with vitamin C.
Related reading: Folic Acid and Folate guide | Vitamin D daily needs and sources | Hifolate Tablet uses in pregnancy
Sources
- NIH Office of Dietary Supplements: Iron fact sheet for consumers
- NIH Office of Dietary Supplements: Iron fact sheet for health professionals
Medical disclaimer: this article is for general information and does not replace advice from a qualified doctor. Do not start, stop or change any supplement or medicine without medical advice.
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