• Iron deficiency is linked to poorer brain health, heart failure, and other health concerns.
• A new study shows nearly 1 in 3 adults in the United States are deficient in this important nutrient.
• The scientists found that the majority of people with iron deficiency are not taking iron supplements.

Screening for iron deficiency is not routine, which makes it difficult to understand its prevalence. A new study, including data from more than 8,000 adults, brings us closer to an answer.

The researchers show that iron deficiency is more common than expected, affecting 29% of adults.

While iron replacement therapies like iron supplements are generally effective and readily available, well over half of individuals with iron deficiency are not receiving treatment. Only 22–35% of women and 12–18% of men with iron deficiency took iron supplements, the study authors found.

The authors of the research, which appears in JAMA Network Open, call for more research into how this nutritional shortfall might influence the health of the population. They also invite discussion about screening strategies.

Why is iron so important for health?

Iron is an essential nutrient that plays a wide range of roles in the human body. Perhaps most famously, it is an important component of hemoglobin, which carries oxygen in the blood.

It is also important for a range of metabolic processes, including DNA synthesis and energy production.

A common condition caused by low iron stores is iron deficiency anemia, but inadequate iron is also associated with a range of other health conditions.

For instance, according to the authors of the new study, iron deficiency is also linked to:

• restless leg syndrome
• decreased physical ability
• impaired brain function
• heart failure
• increased risk of death

Experts consider iron deficiency to be a leading contributor to the global disease burden.

Iron deficiency: Signs and risk factors

People who are low in iron may experience signs and symptoms, such as:

• a pale complexion
• fatigue
• trouble breathing, especially after exercise
• weakness
• rapid heartbeat
• headache
• a sore or smooth tongue
• hair loss or brittle nails

As the new research has shown, iron deficiency is very common, but some people have an increased risk. Risk factors of iron deficiency may include:

• menstruation
• pregnancy and breastfeeding
• surgery or trauma
• gastrointestinal diseases (i.e., celiac disease)
• peptic ulcer disease
• veganism and vegetarianism

While adequate iron is vital for good health, too much iron can cause problems. So, anyone who believes they may have iron deficiency should consult their doctor before starting supplements.

“Excessive iron intake can cause gastrointestinal side effects, or even iron overload, which is called hemochromatosis,” explained Yaa Boakye, a registered dietitian nutritionist and nutrition consultant, who was not involved in the study.

“Monitoring iron levels with a healthcare provider ensures that supplementation is done safely and appropriately,” Boakye told Healthline.

How to get more iron in your diet

Although iron deficiency is widespread, iron-rich foods can help boost iron levels.

The most well-known source of iron is red meat. Iron from animal sources is called heme iron, whereas iron from plants is referred to as non-heme iron. Of the two, heme iron is much easier for the body to absorb.

However, too much heme iron may be linked to an increased risk of type 2 diabetes, and red meat consumption — in excess — is also linked to increased disease risk.

“The dose makes the poison,” Boakye said. “Red meat itself isn’t inherently harmful in small amounts. The issue arises when it’s consumed in excess, especially fatty cuts, larger portions, or processed forms, such as bacon and sausage,” she added.

Boakye explained that consuming large amounts of red meat regularly — especially processed meats — is also associated with an increased risk of heart disease, colon cancer, and more.

Adrian Hernandez, a certified gastrointestinal dietitian nutritionist and owner of AEH Nutrition, not involved in the study, explained that heme iron — the form most easy to absorb — is available in foods other than red meat, including:

• poultry
• fish
• shellfish
• eggs

As for plant-based sources, “Non-heme iron foods include whole grains, dark leafy greens, tofu, nuts and seeds,” he told Healthline.

Avery Zenker, a registered dietitian, suggested some more non-heme iron sources:

• lentils
• peas
• soybeans
• tempeh
• beans
• dried fruits (i.e., figs, dates, and prunes)
• tomato paste
• artichokes
• potatoes
• blackstrap molasses
• cocoa powder
• dark chocolate

Zenker, who was not involved in the research, told Healthline that many products are now fortified with iron, too.

According to Rebecca Russell, a functional medicine registered dietitian who was not involved with the study, “Iron deficiency has been a long-standing concern prompting food companies to fortify grain-based products, such as breakfast cereals, with additional iron.”

Other ways to support healthy iron levels

Beyond focusing on iron-rich foods, there are other ways to help your body maintain adequate levels:

The importance of vitamin C

“Vitamin C-rich foods enhance the absorption of iron,” Hernandez explained. This means eating these foods alongside iron-rich foods can increase levels further. Hernandez noted a few foods rich in vitamin C, such as:

• citrus fruits
• bell peppers
• tomatoes
• berries
• tropical fruits (i.e., kiwi)

Cookware plays a part

“Another non-food strategy for boosting iron levels is cooking with iron cookware,” Russell said. “Research suggests that cooking in iron pots and pans can significantly increase both the iron content and bioavailability of food.”

Coffee, tea, and wine

Zenker advised avoiding tea or coffee close to meals. These drinks contain tannins that can inhibit iron absorption. “Red wine contains polyphenols that have been shown to also decrease iron absorption,” she added.

Calcium

Calcium, which is rich in milk and other dairy products, can also limit how much iron is absorbed. “If you’re taking a calcium supplement or eating calcium-rich foods (like dairy), try to consume them at a different time from your iron sources,” explained Zenker.

Takeaway

A new study finds that around 1 in 3 adults in the U.S. lacks iron. However, a range of simple strategies that don’t rely on red meat consumption can help maintain adequate levels. This includes eating iron-rich foods, not drinking tea or coffee too close to meals, and cooking in iron pans.