When you’re feeling unusually tired, you probably take inventory of your sleep schedule or vow to block out more time on your calendar for R&R. No doubt, these steps can support overall health and well-being—but for the estimated 10 million people in the United States who are iron deficient, these tactics alone won’t cut it.
“Consuming adequate iron is essential for sound energy levels,” says Kevin Huffman D.O., a doctor of osteopathic medicine and licensed wellness specialist who primarily works with people with chronic fatigue. As such, “one of the common hidden causes of chronic fatigue is low iron,” he says. And while exhaustion is common amongst those with low iron, unfortunately, the impacts of falling short on this mineral don’t end there.
Here’s what you should know about why adequate iron intake is important for your overall health and well-being—plus five tips for boosting iron intake and absorption to reduce your risk of iron deficiency.
- ABOUT OUR EXPERTS: Kevin Huffman D.O., is a doctor of osteopathic medicine and licensed wellness specialist who primarily works with people with chronic fatigue. Amy Goodson, M.S., R.D., C.S.S.D., L.D., is a sports dietitian and author of The Sports Nutrition Playbook. Krutika Nanavati, R.D.N., is a registered dietitian nutritionist and consultant at Clinicspots.
Why Iron Is So Important
A mineral that the body cannot create on its own, iron must be obtained through diet. The nutrient’s main job is to support the production of hemoglobin, which is the protein in red blood cells responsible for transporting oxygen throughout the body, as well as removing carbon dioxide from the body, according to sports dietitian Amy Goodson, M.S., R.D., C.S.S.D., L.D., author of The Sports Nutrition Playbook. Oxygen functions as energy for cells, giving them the fuel they need to reproduce and grow. Meanwhile, carbon dioxide is a biological waste product that can be toxic in high quantities. So, without ample iron, energy levels dip and excess carbon dioxide remains circulating in the blood, explains Goodson.
Iron also plays a vital role in immune system functioning. In one 2023 study published in Nature Immunology, researchers found that a protein in immune cells in the gut (called transferrin receptor) absorbs iron. They found that once inside these immune cells, iron regulates cell functioning, supporting the cells as they work as bodyguards, fighting off infection-causing pathogens. When iron levels are low, these protective immune cells are less active, and therefore less effective at fighting off infection (particularly in the gut), the study suggests.
Beyond that, iron supports overall metabolism, muscle health and function, and hormone production, according to the U.S. Department of Health & Human Services. The mineral also helps maintain healthy skin, hair, and nails.
The Low Iron and Fatigue CoNnection
Because of the mineral’s role in oxygen transport, the most common symptom of low iron is fatigue. When iron levels are low, the body produces suboptimal levels of hemoglobin. “This means oxygen transport in the blood is impaired and that less oxygen is delivered to tissues and organs,” Goodson says. Oxygen functions as fuel for your body like gasoline does for vehicles, so asking your body to execute functions with less oxygen is like asking a car to keep chugging when the tank is empty.
Read More: 8 Possible Reasons Why You’re So Tired All The Time
When oxygen levels are low, the body has to work way harder to move and function, says Goodson. The extra work is quite taxing on the system and can lead to increased tiredness throughout the day, as well as generalized fatigue long-term.
Other Symptoms Of Low Iron
In addition to unusual tiredness and generalized fatigue, “low iron can cause pale skin, brittle nails, hair loss, shortness of breath, dizziness, headaches, and cold hands and feet,” says registered dietitian nutritionist Krutika Nanavati, R.D.N., a consultant at Clinicspots.
Prolonged and severe iron deficiency can lead to a condition called iron deficiency anemia, which is marked by inadequate healthy red blood cells in the system, says Nanavati. “Iron deficiency anemia is characterized by even more severe symptoms, such as rapid heartbeat, chest pain, and cravings for non-food items like ice or dirt (a condition known as pica),” she says. Notably, women are at a higher risk for iron deficiency anemia compared to men, according to the U.S. Department of Health & Human Services, with pregnant women and those with heavy menstrual periods at especially high risk.
How Much Iron Do You Need?
Iron needs depend on your age, sex, as well as overall health status. The Food and Nutrition Board at the Institute of Medicine recommends that men consume eight milligrams of iron per day and that women consume 18. “Women and menstruating individuals have higher daily iron needs because they lose blood during menstruation,” explains Nanavati.
Read More: An OBGYN’s Guide To Making Menstruation Less Of A Pain
Pregnant women are encouraged to consume an additional nine milligrams of iron per day, for a total of 27 milligrams. Because blood volume increases during pregnancy, so do iron needs. “This additional iron helps supply oxygen to the fetus,” Goodson says.
“People with certain medical conditions, such as chronic kidney disease, celiac disease, and gastrointestinal issues, may also have additional daily iron requirements, as [these conditions] can affect iron absorption,” says Goodson. Individuals who regularly donate blood may also have increased needs, adds Nanavati.
How To Increase Iron Levels to Fight Fatigue
1. Eat More Red Meat and Organs
The body cannot make iron the way it can vitamin D or vitamin B3, which means we need to consume iron-containing foods. Animal-based foods like red meat, liver, other organ meats, and oysters are the absolute best source of iron, as they contain high amounts of a specific type of iron called heme iron, says Goodson.
Read More: The Case For Eating More Organ Meats—And How To Go About It
Heme iron is well-absorbed by the body, according to research published in Nutrients. That means that if you consume three ounces of beef liver or oysters, for example, your body will absorb most of the respective five and eight milligrams of iron in your food.
If liver, other organ meats, and oysters aren’t your thing, “consuming high-quality animal proteins like lean beef, turkey, and chicken is a good way to fortify your diet with iron,” suggests Goodson.
2. Ramp Up Leafy Green Intake
Good news: If you are an exclusively plant-based eater and can’t get your iron from red meat, or have to be mindful of meat intake due to concerns like diabetes or cardiovascular disease, you can still get enough iron from your diet.
“Dark green leafy vegetables like kale, chard, beet greens, and collard greens have high levels of iron,” says registered dietitian Emily Van Eck, M.S., R.D.N. One cup of raw kale has more than one milligram of iron, while one cup of raw spinach has 0.8 milligrams. That means a hearty salad can put a notable dent in your overall iron needs with its base alone.
If you want more variety beyond greens, other plant-based foods like beans, lentils, tofu, spinach, quinoa, pumpkin seeds, and nuts also offer iron.
Notably, all non-animal sources of iron contain a specific type of iron called non-heme iron, which is not as well-absorbed by the body, according to Goodson. Not to worry, though; you can bolster your absorption of non-heme iron-containing foods by consuming them with vitamin C.
3. Increase Vitamin C Consumption
Whenever you’re consuming plant-based sources of iron, Nanavati recommends combining them with foods that provide vitamin C, such as citrus fruits, strawberries, kiwi, bell peppers, and broccoli.
“Vitamin C enhances iron absorption by converting non-heme iron into a more absorbable form,” she explains. Indeed, research published in Blood in 2023 found that adding vitamin C to iron supplementation led to “statistically significant” increases in the amount of iron absorbed.
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4. Avoid Pairing Iron-Rich Foods With Absorption Inhibitors
Your efforts to consume more iron can be thwarted if you consume foods with high levels of phytates, polyphenols, or calcium—especially if you’re consuming your iron from plant-based foods, according to Nanavati.
One study published in The Encyclopedia of Food and Health reports that non-heme iron absorption is inhibited by phytic acid and polyphenols, which bind to the non-heme iron, creating an insoluble (or non-absorbable) compound that is not able to enter the intestinal cells.
Phytates and phytic acids are primarily found in whole grains and legumes, while polyphenols are primarily found in tea, coffee, and red wine, according to Nanavati.
If you’re experiencing fatigue or other symptoms related to iron deficiency, she suggests doing your best to avoid combining plant-based iron sources with foods containing high levels of these inhibitors. “You can also mitigate the presence of these iron-blocking chemicals by soaking, sprouting, or fermenting iron foods that contain them,” according to Huffman. These preparation methods are game-changing for reaping the benefits of plant-based iron foods like whole grains and legumes.
Calcium, which is primarily found in dairy foods, also inhibits the absorption of both heme and non-heme iron, according to Goodson. As such, consuming dairy products at different meals from your iron-rich ones can be beneficial for individuals with iron deficiency.
5. Consider An Iron Supplement
If you’ve been diagnosed with iron deficiency or iron deficiency anemia (which can be determined through a blood test), an iron supplement may be helpful. Ditto goes for those considered at a heightened risk for deficiency, such as pregnant women, vegetarians, and vegans. (Unsurprisingly, plant-based eaters face an increased risk for deficiency, research shows.)
Generally speaking, “iron is not a supplement you should take without healthcare provider guidance, as it can cause nausea and constipation,” says Goodson. Other common side effects of iron supplementation include diarrhea, flatulence, metallic taste, staining of the teeth, epigastric distress, and changes in stool color and consistency.
With your doctor’s green light, Goodson suggests opting for an iron supplement that contains a well-absorbed form of iron, such as ferrous gluconate or ferrous sulfate. “Ferrous sulfate iron is slower digesting and can also be easier on the stomach, helping to minimize nausea and other gastrointestinal distress,” she says. Given that vitamin C supports iron absorption, you should also seek a supplement that contains C. Or, simply make an effort to take your supplement with orange juice or a vitamin C-rich food.