You know the feeling: You’re at the bottom of a hill, and you just can’t imagine getting to the top. What’s wrong? you ask yourself. Why am I so tired? One reason for that sluggish feeling could be iron deficiency.

“Iron has the purpose of transporting oxygen in red blood cells to produce energy,” Amy Reed, RDN, spokesperson for the Academy of Nutrition and Dietetics, based in Cincinnati, Ohio explains to Bicycling. “If iron is low then there are not enough red blood cells available to carry the oxygen to provide the energy and you become tired.”

Iron deficiency—and iron-deficiency anemia, which is more serious—is officially diagnosed by a blood test ordered by your doctor. If you’re fatigued or have the other symptoms listed here, you should talk to your doctor about getting a test. Feeling like your best self means having enough energy to do the things you want to do and iron deficiency can hold you back from that. Fortunately, it’s both common and easy to treat, so all you have to do is spot it first.

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To help you pinpoint whether you might be missing as much of this mineral as you require, here is a list of risk factors and other signs of iron deficiency, in addition to fatigue.

What Puts You at Risk for Iron Deficiency

While iron is present in many foods, we don’t all eat those foods consistently. For example, animal products are richer in a more easily-absorbed iron, so vegetarians and vegans are more likely to become iron deficient. Also, some foods inhibit absorption, such as coffee, tea, and high-fiber cereals, so if you’re relying on your fortified morning cereal to give you iron, but it’s also very fibrous, that iron may not be helping you much.

Meanwhile, young women lose blood—and therefore, iron—through menstruation. So while men and post-menopausal women require 8 milligrams (mg) of iron per day, those who get their periods need 18 mg per day to make up for loss of blood.

Along with weak absorption, there are other issues that can exacerbate iron deficiency. For example, “training when you’re low on iron can lead to inflammation, and that can trigger the release of a molecule called hepcidin from the liver,” explains Guillem Gonzalez-Lomas, M.D., an orthopedic surgeon at NYU Langone’s Sports Medicine Center. “Hepcidin sequesters the iron and prevents it from being used by the body, lowering the functional deficit even further.”

It’s important to note that “being low in iron is not the same as being anemic,” says Priya Lawrence, MS, RD, CDN, cofounder of Tried and True Nutrition, Inc. in New York City. “When you’re anemic, you are low in hemoglobin.” Hemoglobin is a protein in your red blood cells that carries oxygen to your body’s organs and tissues and transports carbon dioxide from your organs and tissues back to your lungs. Iron is mostly stored in the body in the hemoglobin, although about one-third of iron is also stored as ferritin and hemosiderin in the bone marrow, spleen, and liver.

If you’re fatigued and have any of these other signs of iron deficiency, listed below, make sure to see your doctor so they can help determine if you are low in iron, anemic, or have another health issue.

4 Signs of Iron Deficiency

1. You’re paler than usual

If you feel like you look washed out or are lacking that healthy pink-cheeked look, it’s a sign that you may be iron deficient. It’s not just about your skin, either. If you’re lacking iron, you might also notice paleness in your gums or your nails, too, says Reed.

2. You’re sometimes dizzy

Your body knows when it’s low on iron and it wants to send the most iron-rich blood to the brain and heart, so when you’re low in iron, you might get dizzy as your body moves blood quickly to your most important organs.

3. You get headaches

When your brain doesn’t get enough oxygen-rich blood, the blood vessels swell which causes pain, or a headache. So, if you’re prone to headaches in combination with any of these other symptoms, a blood test might be in order to check your iron levels, Reed explains.

4. Your tongue is redder than usual

Have you ever wondered why your dentist checks your tongue during an annual exam? It’s because the tongue tells many secrets. A bright red tongue can signal a number of deficiencies, including iron, folic acid, and vitamin B12. If your dentist mentions the color of your tongue (or if you think it’s red like a strawberry), let your doctor know.

Plan Your Meals to Prevent Iron Deficiency

If you find out you are low in iron, your doctor may suggest eating more iron-rich foods.

“There are two sources of iron; heme iron from animal sources and non-heme iron from plant sources,” explains Reed. “The iron from animal sources is better absorbed by the body, and both types of iron are better absorbed when eaten with a vitamin C-rich food.”

Reed suggests a few easy combinations, including:

  • Black beans mixed with tomato salsa
  • Cooked oatmeal topped with strawberries
  • Spinach salad topped with tomatoes
  • Steak stir-fry with red peppers

Finally, cooking acidic foods in cast iron cookware can also help increase the amount of iron in a meal.

Talk to Your Doctor About Iron Supplements

Including a multivitamin with iron can be a way to prevent iron-deficiency anemia, explains Reed. “Take the vitamin with 100% orange juice or make sure your breakfast includes a vitamin C-rich food like strawberries,” she suggests.

While your doctor may suggest an iron supplement, “sometimes people do not tolerate the vitamins well if they take them on an empty stomach,” Reed says. She adds that you should always speak with your health care provider before taking an iron supplement because blood work will determine the appropriate dose.

Headshot of Donna Raskin
Donna Raskin

Donna Raskin has had a long career as a health and fitness writer and editor of books and magazine articles. She bikes in a nearby county park, lifts weights, takes Zumba, and loves to walk/run with her dog, Dolly.