Iron: Best for Energy, Brain, Immunity and More

Iron is a trace mineral that your body needs to function properly. Although you need it in small amounts, it plays a huge role in your health - especially in carrying oxygen throughout your body.

Most of the iron in your body is found in hemoglobin, a protein in red blood cells that transports oxygen from your lungs to your tissues. Iron is also part of myoglobin, which supplies oxygen to muscles, and it's crucial for enzymes involved in metabolism, energy production, and even brain development.

Since your body can't produce iron on its own, you need to get it from your diet or supplements.

Functions of Iron in the Body

Iron does a lot more than you might think. Its main functions include:

• Oxygen Transport: Hemoglobin needs iron to bind oxygen in your blood. Without it, your cells and organs wouldn't get the oxygen they need to work.

• Energy Production: Iron helps convert food into energy, especially in your muscles.

• Immune Function: It supports a healthy immune response by helping your body fight infections.

• Brain Health: Iron is essential for brain development in children and mental performance in adults.

• Cellular Function: Iron is involved in DNA synthesis and many enzyme reactions.

How Much Iron Do You Need? Daily Requirements by Age and Sex

Your iron needs depend on your age, sex, and health status. According to the National Institutes of Health (NIH), here are the recommended daily intakes:

Women of reproductive age need more iron due to blood loss from menstruation. Pregnancy also increases iron requirements significantly.

Types of Iron in Food: Heme vs. Non-Heme

Iron comes in two main forms:

• Heme Iron: Found in animal products like red meat, poultry, and fish. It's more easily absorbed by the body.

• Non-Heme Iron: Found in plant-based foods like beans, lentils, tofu, and fortified cereals. Absorption is lower, but can be improved with vitamin C.

Best Food Sources of Iron

Here are some of the most iron-rich foods to include in your diet:

Heme Iron Sources (More Absorbable)

• Beef, liver, lamb, and pork

• Chicken and turkey (especially dark meat)

• Tuna and sardines

• Shellfish like clams, mussels, and oysters

Non-Heme Iron Sources (Plant-Based)

• Lentils, chickpeas, and beans

• Tofu and tempeh

• Fortified cereals and grains

• Pumpkin seeds and sunflower seeds

• Spinach, kale, and swiss chard

Tip: Eat non-heme iron foods with vitamin C-rich foods (like oranges, tomatoes, or bell peppers) to increase absorption.

Signs and Symptoms of Iron Deficiency

Iron deficiency is the most common nutrient deficiency worldwide, especially among women, children, and vegetarians. It can lead to iron-deficiency anemia, where the body doesn’t have enough healthy red blood cells.

Early symptoms include:

• Fatigue and weakness

• Pale skin

• Shortness of breath

• Cold hands and feet

• Dizziness or headaches

• Restless legs

• Poor concentration or brain fog

• Brittle nails or hair loss

If left untreated, it can affect physical performance, cognitive function, and immunity.

Who’s Most at Risk for Iron Deficiency?

You may be at a higher risk if you:

• Are a woman with heavy menstrual periods

• Are pregnant or breastfeeding

• Follow a vegetarian or vegan diet

• Have frequent blood loss (donation, ulcers, etc.)

• Have digestive conditions like celiac disease or inflammatory bowel disease (IBD)

• Are an endurance athlete

Should You Take Iron Supplements? What to Know

Iron supplements can help people who are low in iron or anemic. However, they should only be taken under medical supervision - too much iron can be harmful.

Common Types of Iron Supplements

• Ferrous sulfate - most common and inexpensive, but may cause constipation

• Ferrous gluconate - gentler on the stomach

• Iron bisglycinate - better tolerated and absorbed for some people

Tips for taking iron:

• Take on an empty stomach if possible (unless it upsets your stomach)

• Avoid taking with calcium, dairy, coffee, or tea - they block absorption

• Vitamin C improves absorption, so pair with citrus or a supplement

The upper limit for adults is 45 mg/day unless otherwise directed by your doctor.

Can You Get Too Much Iron?

Yes. Excessive iron intake can cause symptoms like nausea, vomiting, stomach pain, and - over time - damage to organs like the liver. Conditions like hemochromatosis, a genetic disorder, cause the body to absorb too much iron from food.

That’s why it's important to only supplement iron when needed and avoid mega-doses without testing your levels first.