Iron in Your Diet – Not Enough or Too Much?

4 min read  |  August 27, 2021  | 
Disponible en Español |

Iron is an essential nutrient in everyone’s diet, and it’s the most common mineral deficiency, especially in women and children. 

You need to consume enough iron for proper growth and development and create red blood cells, which carry oxygen throughout the body. Not enough iron can make you weak with anemia. Too much iron can overload the blood and cause iron poisoning.

Eating a well-balanced diet doesn’t mean you get enough iron.

“Even if you eat a variety of foods, you might still become anemic,” says Lesley Klein M.S., RD, LD/N, a dietitian with Sylvester Comprehensive Cancer Center. 

“Just because a food contains ‘x amount’ of iron doesn’t mean that you will necessarily absorb all of it.” What you eat along with iron-rich foods can either help or hinder your body’s iron absorption. “A compound called tannins — found in coffee, tea, barley, wine, and unripe fruit like green bananas — can inhibit the absorption of iron. You could be eating a big juicy steak rich in heme iron (from animal sources), but if you drink a glass of iced tea or red wine with the meal, you most likely won’t absorb all of the iron,” Klein says. 

In contrast, Vitamin C enhances the absorption of non-heme iron (from plant sources). “For example, if you are eating a spinach salad, which is rich in iron, you would absorb the iron better if you added strawberries, mandarin oranges, or red bell peppers to the salad, as they contain Vitamin C.”

How can you tell if you’re getting enough iron?

The following symptoms can be signs of iron deficiency or anemia, which cannot be self-diagnosed.

  • Extreme fatigue and weakness
  • Pale skin
  • Chest pain
  • Rapid heartbeat
  • Shortness of breath
  • Headache, dizziness, or lightheadedness
  • Cold hands and feet
  • Inflammation or soreness of your tongue
  • Brittle nails
  • Poor appetite or unusual cravings for non-food items

If you or your child are experiencing any of these symptoms, talk to your primary care physician, who can order a simple blood test.

“If your labs are low in iron, you should probably take an iron supplement, as well as make better choices of iron-rich foods in your diet. In general, nutrients are better absorbed when they come from food sources,” Klein says. “However, when labs get low, it may be difficult to bring those numbers up with diet changes alone.”

If left untreated, anemia can get worse and lead to an enlarged heart or heart failure, delayed growth and development in infants and children, increased risk of infections, and premature birth/low birth weight for pregnant women.

How much is too much iron?

If you’re consuming too much iron (typically, this happens when taking high-dose supplements for long periods), you may experience certain warning signs. 

  • Stomach pain
  • Nausea
  • Chronic fatigue
  • Cirrhosis of the liver or liver cancer
  • Diabetes
  • Irregular heart rhythms
  • Skin color changes (bronze, gray, green)

Just like iron deficiency, iron poisoning or overload can be diagnosed only with a blood test.

“Excess iron accumulates in internal organs, most often liver, heart, and pancreas. Too much iron can lead to liver disease, heart problems, and diabetes,” Klein says. “Observational studies suggest that a high intake of heme iron (iron from animal sources) may increase the risk of colon cancer. If something is good, more is not necessarily better!”

If you are menstruating monthly or donate blood regularly, you most likely will not have issues with iron overload.

What are good sources of iron?

Sources of heme iron (iron from animal sources):

  • Eggs
  • Red meat
  • Pork
  • Poultry
  • Fish
  • Seafood/shellfish

Sources of non-heme iron (plant sources of iron):

  • Beans
  • Blackberries, raspberries
  • Bran flakes cereal
  • Broccoli
  • Brown rice
  • Brussel sprouts
  • Bulgur
  • Cantaloupe
  • Carissa
  • Corn
  • Couscous
  • Dark leafy greens
  • Dried fruit
  • Hummus 
  • Iron-fortified cereals, bread, oatmeal, and pasta
  • Jackfruit
  • Lentils
  • Lima beans
  • Nuts
  • Oat bran 
  • Orange
  • Papaya
  • Passion fruit
  • Pearled barley 
  • Peas
  • Plantains
  • Potato and sweet potato with skin
  • Quinoa
  • Sapodilla
  • Seaweed
  • Seeds (pumpkin, sesame, hemp, flax)
  • Soursop
  • Soybeans
  • Spirulina
  • Tamarind
  • Tofu and tempeh
  • Tomato paste and sauce
  • Watermelon
  • Wild and white long-grain rice, enriched

Dana Kantrowitz is a contributing writer for UMiami Health News.

Tags: iron, Lesley Klein, nutrititon

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