what you need to know

Have you been feeling exhausted lately? Despite your physical fitness, can you hardly make it up the stairs without dizziness? If so, you may be lacking in iron — especially if you’re a woman.

Although many people don’t consider iron a nutrient, you might be surprised to learn that low iron is the most common dietary deficiency in the United States. Almost 10% of women suffer from iron deficiency and prevention, according to figures from the Centers for Disease Control.

Let’s look at why iron is so important to your body, what can happen if you don’t get enough of it, and when you need to take an iron supplement.

Why do you need iron?

Iron is an essential mineral. “The main reason we need it is because it helps carry oxygen around the body,” says Paul Thomas, EdD, RD, a scientific advisor to the National Institutes of Health, Office of Dietary Supplements.

Iron is an important part of hemoglobin, the substance in red blood cells that carries oxygen from your lungs to carry it throughout your body. Hemoglobin makes up about two-thirds of the iron in the body. If you don’t have enough iron, your body can’t make enough healthy, oxygen-carrying red blood cells. A lack of red blood cells is called iron deficiency anemia.

Without healthy red blood cells, your body can’t get enough oxygen. “If you don’t get enough oxygen in your body, you get tired,” says Thomas. This fatigue can affect everything from your brain function to your immune system’s ability to fight off infection. If you’re pregnant, severe iron deficiency can increase your baby’s risk of being born prematurely or smaller than normal.

Iron also has other important functions. “Iron is also necessary for maintaining healthy cells, skin, hair, and nails,” says Elaine Chottiner, MD, clinical assistant professor and director of the Clinics of General Hematology at the University of Michigan Medical Center, in an email interview.

How Much Iron Do You Need?

How much iron you need each day depends on your age, gender, and overall health.

Infants and young children generally need more iron than adults because their bodies are growing so quickly. During childhood, boys and girls need the same amount of iron — 10 milligrams daily from ages 4 to 8 and 8 mg daily from ages 9 to 13.

From puberty onwards, a woman’s daily iron requirement increases. Women need more iron because they lose blood each month during their periods. For this reason, women between the ages of 19 and 50 need to consume 18 mg of iron daily, while men of the same age can get by with just 8 mg.

After menopause, a woman’s need for iron decreases as her menstrual cycle ends. After a woman enters menopause, men and women need the same amount of iron – 8 mg per day.

You may need more iron, either from dietary sources or from an iron supplement, if you:

• Are pregnant or breastfeeding
• have kidney failure (especially if you are on dialysis, which can remove iron from the body)
• Have an ulcer that can cause blood loss
• Do you have a gastrointestinal condition that prevents your body from absorbing iron normally (eg, celiac disease, Crohn’s disease, or ulcerative colitis)
• Take too many antacids, which can prevent your body from absorbing iron
• Had weight loss (bariatric) surgery
• Exercise a lot (intensive exercise can destroy red blood cells)

If you’re a vegetarian or vegan, you may also need to take an iron supplement since the body doesn’t absorb iron found in plants as well as iron from meat.

How do you know if you are iron deficient?

“People often don’t know they have anemia until they have signs or symptoms — they appear pale or ‘sallow,’ are tired, or have trouble moving,” says Chottiner.

If you’re low on iron, you can also:

• Feel short of breath
• Have a fast heartbeat
• Got cold hands and feet
• Crave strange substances like earth or clay
• Do you have brittle and spoon-shaped nails or hair loss?
• sores at the corners of the mouth
• A sore tongue
• Severe iron deficiency can cause difficulty swallowing

If you’re tired and sluggish, see your doctor. “It’s pretty easy to identify and diagnose the different stages of iron deficiency with a simple blood test,” says Thomas. Pregnant women and people with gastrointestinal diseases such as Crohn’s disease, ulcerative colitis or celiac disease should have their iron levels tested regularly.

Do you need to take an iron supplement?

If your iron levels are low, a diet high in iron-rich foods like fortified grains, red meat, dried fruits, and beans may not be enough to give you what you need. Your doctor may recommend taking an iron supplement.

Can iron supplements have side effects?

Iron supplements can cause side effects, usually stomach problems such as nausea, vomiting, diarrhea, dark stools, or constipation. Pregnant women are particularly prone to constipation. Adding extra fiber to your diet can help alleviate this symptom. A stool softener can also make you feel better.

Start with a low iron dose and then gradually increase the dose to the recommended daily allowance to minimize side effects. If your iron supplements upset your stomach, your doctor may adjust the dose or form of iron you use. You can also try taking the supplements with food.

Can you take too much iron?

Unlike some supplements, more is definitely not better when it comes to iron. Adults should not take more than 45 mg of iron per day unless they are being treated with iron under close medical supervision.

Iron overdose can be particularly toxic to children. “Iron supplements have killed young children because their needs for iron are relatively small compared to that of an adult,” says Thomas. If you’re taking iron supplements, it’s very important to keep them in a tall, locked cupboard, well out of the reach of your children. Symptoms of iron poisoning include severe vomiting, diarrhea, abdominal pain, dehydration, and bloody stools in children.

It is difficult for adults to overdose on iron from food and supplements alone, as an adult body has systems in place to regulate the amount of iron it absorbs. However, people with hereditary hemochromatosis have trouble regulating their iron intake.

Although most people absorb only about 10% of the iron they ingest, people with hemochromatosis absorb up to 30%. As a result, the iron in their bodies can build up to dangerous levels. This excess iron can build up in organs like the liver, heart, and pancreas, which can lead to conditions like cirrhosis, heart failure, and diabetes. For this reason, people with hemochromatosis should not take iron supplements.