Feeling tired all the time? Iron is often the first nutrient people suspect, and iron pills are easy to grab at any pharmacy. But iron is one of those supplements where guessing can backfire. Too little causes real problems. Too much causes real problems, too.
The good news is that most people can get the iron they need from food, and the people who truly need a supplement usually benefit from a quick blood test first. Here’s who needs extra iron, how to get more from your meals, and how to take a supplement so it actually works.
What Does Iron Do?
Your body uses iron to make hemoglobin, the protein in red blood cells that carries oxygen from your lungs to the rest of your body. It also makes myoglobin, which brings oxygen to your muscles, and it helps make some hormones.
When your iron stores run low, your body can’t make enough healthy red blood cells. That’s called iron deficiency anemia. Iron is one of many minerals with big jobs, and our article on mineral nutrition shows how they fit together.
How Much Iron Do You Need?
It depends a lot on your age and sex. The NIH Office of Dietary Supplements lists these daily recommended amounts:
- Men 19 and older: 8 milligrams (mg)
- Women 19 to 50: 18 mg
- Adults 51 and older: 8 mg
- Teen girls 14 to 18: 15 mg (teen boys need 11 mg)
- Pregnancy: 27 mg
- Breastfeeding: 9 mg for adult women
Notice the gap: a woman in her 30s needs more than twice as much iron as a man the same age, mostly because of monthly blood loss. After menopause, her needs drop to match his.
Vegetarians who skip meat, poultry and seafood need almost twice as much iron as those numbers, because the body doesn’t absorb plant iron as well.
Food First: Where Iron Comes From
Iron in food comes in two forms. Heme iron is found in meat, poultry and seafood, and your body absorbs it well. Nonheme iron is found in plant foods and fortified foods, and it’s absorbed less efficiently. Here are some solid sources, with amounts from the NIH Office of Dietary Supplements:
- Fortified breakfast cereal with 100% of the Daily Value, 1 serving: 18 mg (check the label, since brands vary)
- Oysters, 3 ounces cooked: 8 mg
- White beans, 1 cup canned: 8 mg
- Beef liver, 3 ounces pan fried: 5 mg
- Lentils, ½ cup boiled: 3 mg
- Spinach, ½ cup boiled: 3 mg
- Firm tofu, ½ cup: 3 mg
- Dark chocolate (45% to 69% cacao), 1 ounce: 2 mg
- Chickpeas or kidney beans, ½ cup: 2 mg
- Lean beef, 3 ounces braised: 2 mg
- Baked potato with skin, 1 medium: 2 mg
- Raisins, ¼ cup: 1 mg
One catch with spinach: it contains natural compounds that make its iron harder to absorb, so it’s not quite the iron powerhouse its reputation suggests. It’s still a great vegetable.
Easy Ways to Absorb More
You can get more out of plant iron by pairing it with the right foods. Your body absorbs plant iron better when you eat it with meat, poultry, seafood, or foods rich in vitamin C, such as citrus fruits, strawberries, sweet peppers, tomatoes and broccoli. Think bean chili with tomatoes and peppers, or oatmeal with strawberries. Our article on vitamin C has more easy ways to get it from food.
Calcium works the other way. It might interfere with iron absorption, so if you take both calcium and iron supplements, take them at different times of day. That timing tip comes up in our calcium versus magnesium article, too. For the bigger picture on what helps and hurts absorption, see our guide to vitamin absorption factors.
That said, for most people eating a typical mixed diet, these food pairings have only a small effect on overall iron status. They matter most if you’re plant-based or already running low.
Who May Need More Iron
Most people in the U.S. get enough iron. The NIH lists these groups as more likely to fall short:
- Teen girls and women with heavy periods. Heavy menstrual bleeding may account for about a third or more of iron deficiency anemia cases in women of childbearing age.
- Pregnant women and teens. Blood volume rises during pregnancy, and low iron raises the risk of low birth weight and premature birth. The NIH advises pregnant women to talk with their health care provider and take an iron supplement if recommended.
- Infants and young children, especially babies born early or small.
- Frequent blood donors. About 25% to 35% of regular blood donors develop iron deficiency.
- People with cancer, heart failure, or digestive conditions such as celiac disease or Crohn’s disease, or who have had gastric bypass surgery.
- Vegetarians and vegans, because plant iron is absorbed less well.
Signs Your Iron May Be Low
Low iron often causes no obvious symptoms at first, because your body draws on its stored iron. As stores run out, symptoms may include feeling weak or tired more than usual, headaches, dizziness, trouble concentrating, pale skin, shortness of breath, brittle nails, and craving ice. Low iron has also been linked with restless legs, which we touch on in can vitamin deficiencies affect sleep.
Here’s the important part: those symptoms have plenty of other causes, too, including low vitamin B12, which can also cause anemia. Our article on who needs vitamin B12 covers that one. The only way to know is a blood test. A clinician may check a complete blood count along with iron levels, often including ferritin, which reflects your iron stores.
Don’t skip the “why.” Iron deficiency is a sign that something is off, not a diagnosis by itself. Bleeding is a common cause, including heavy periods, ulcers, long-term use of aspirin or ibuprofen, and sometimes cancers of the digestive tract. That’s especially worth checking in men and in women after menopause, who don’t lose iron each month. Taking iron pills without finding the cause can cover up a problem that needs attention.
If You Need a Supplement: How to Take It
If your clinician recommends iron, a few practical points can make it easier on you.
Read the Label for Elemental Iron
Iron supplements come in forms like ferrous sulfate, ferrous gluconate, ferrous fumarate and ferric citrate. Each has a different share of actual iron, called elemental iron. Ferrous fumarate is about 33% elemental iron, ferrous sulfate is 20%, and ferrous gluconate is 12%. The good news: the Supplement Facts panel lists the elemental iron for you, so there’s no math needed. Iron-only pills often provide 65 mg, well above the Daily Value, so they’re best used when you’ve been told you need them.
Expect Some Stomach Side Effects
Doses of 45 mg a day or more may cause nausea and constipation, and taking iron on an empty stomach can make an upset stomach more likely. Some other forms, such as iron amino-acid chelates, carbonyl iron, and polysaccharide-iron complexes, might cause fewer stomach problems, but the evidence there is limited. If side effects are a problem, ask your clinician or pharmacist about switching forms or adjusting the schedule rather than just quitting.
Every Other Day May Work Just as Well
This is a newer finding that’s worth knowing about. A dose of iron triggers a hormone called hepcidin that temporarily lowers how much iron you absorb from the next dose. In a small 2017 trial in iron-depleted young women, taking iron every other day led to higher total absorption than taking it every day, and splitting the dose into two daily doses didn’t help. A 2020 follow-up in women with iron deficiency anemia found absorption was 40% to 50% higher when a dose came after a day off.
These were short absorption studies in a few dozen women, not long-term treatment trials, so they don’t settle the question. But they’re a good reason to ask your clinician whether every-other-day dosing makes sense for you, especially if daily iron upsets your stomach. Don’t change a prescribed plan on your own.
Risks and Interactions
Iron is a supplement where more is definitely not better.
- Upper limit. For adults, the upper limit is 45 mg a day from all sources, including food and supplements. A doctor may prescribe more for a short time to treat a deficiency.
- Keep it away from kids. Accidental overdose of iron-containing products is a leading cause of fatal poisoning in children under 6. Keep iron and multivitamins with iron in child-resistant containers, up high and out of sight. Our tips on supplement storage at home can help.
- Hemochromatosis. This inherited condition causes iron to build up to harmful levels, and people who have it should avoid iron supplements and vitamin C supplements.
- Zinc. High doses of iron can decrease zinc absorption. Our article on zinc and how much you need covers that mineral.
Medication Interactions
Iron can interfere with several medicines. According to the NIH Office of Dietary Supplements:
- Levothyroxine (Synthroid, Levoxyl, Unithroid and others) for thyroid conditions can work less well when taken with iron. Some labels advise keeping them at least 4 hours apart.
- Levodopa (found in Sinemet and Stalevo), used for Parkinson’s disease and restless legs syndrome, may be absorbed less when taken with iron.
- Proton pump inhibitors such as omeprazole (Prilosec) and lansoprazole (Prevacid) lower stomach acid, which can reduce absorption of plant iron. People with iron deficiency who take these medicines may respond less well to iron supplements.
Your pharmacist is a great resource here. Bring a list of everything you take, including supplements, and ask how to time your iron.
What About Multivitamins?
Many multivitamins include iron, and some don’t. Since men and adults over 50 need much less iron than younger women, the right choice depends on who’s taking it. If you’re choosing one, check the label for iron and add it to what you get from food. Our guide on how to choose multivitamins walks through what to look for, and multivitamin benefits covers what they can and can’t do. If you’re thinking about minerals more broadly as you age, our article on the best minerals for healthy aging explains why iron isn’t a one-size-fits-all pick. You’ll also find tips on improving mineral intake without guesswork.
Quick Checklist
- Build meals around iron-rich foods like beans, lentils, lean meat, seafood, tofu and fortified cereal.
- Pair plant iron with vitamin C foods like peppers, tomatoes, citrus or berries.
- Take calcium and iron supplements at different times of day.
- Feeling run-down? Get a blood test before reaching for iron pills.
- If you’re low, work with your clinician to find out why.
- Stay under 45 mg a day unless your doctor prescribes more.
- Ask your pharmacist how to time iron with thyroid, Parkinson’s or acid-reducing medicines.
- Store anything with iron where children can’t reach it.
If You Shop With Us
Disclosure: Info Health News is run by an independent Youngevity distributor, and we may earn a commission when you purchase through our links. Product information below comes from the company and is not independent evidence of any health benefit.
Youngevity’s ingredient list for Beyond Tangy Tangerine® 2.5 includes iron along with other vitamins and minerals, which we describe in our Beyond Tangy Tangerine 2.5 overview. Check the Supplement Facts label for the exact amount and count it toward your daily total. A multivitamin isn’t a treatment for iron deficiency anemia, and people with hemochromatosis or who’ve been told to limit iron should read labels closely. To browse or order, visit our Youngevity products page, which links to the online store.
The Bottom Line
Iron matters, but most people get enough from a varied diet. Women with heavy periods, pregnant women, frequent blood donors, plant-based eaters, and people with certain digestive or chronic conditions are the ones most likely to need more. If you suspect low iron, get tested first, find out why it’s low, and let your clinician guide the dose. Taking iron every other day may help absorption, though that research is still early. And because too much iron can be harmful, stay under the upper limit and keep iron supplements far from little hands.
This article is for educational purposes only and isn’t medical advice. Talk with your doctor or pharmacist before starting a supplement, especially if you’re pregnant, take medication or have a health condition. See our medical disclaimer.
