Low iron is one of the most common types of nutritional deficiencies worldwide, and it’s surprisingly prevalent in the U.S., especially among women and children.1 While it might seem relatively unimportant (after all, how much can one nutrient do?) iron actually has a huge impact on your overall health. To understand why, it’s important to know just what iron does for your body.
Iron’s Role in the Body
Iron is essential for several crucial bodily functions, notably the production of hemoglobin. In fact, almost all of the iron in the body is found in hemoglobin, a complex protein that allows red blood cells to maintain their shape and to carry oxygen and carbon dioxide around the body. Basic biology reminder: oxygen is essential for cell metabolism, and carbon dioxide is the waste product from the same process. If there’s too little oxygen or too much carbon dioxide in the blood, every cell in the body is at risk for damage.
Iron is also a key player in many enzyme-based processes in the body, including the conversion of certain amino acids into neurotransmitters that keep the brain working properly. It also helps the body break down proteins and maintain balanced hormone levels, among many other things.
Bottom line: when your iron levels aren't what they should be, it can affect your whole body, beginning at the cellular level.
Why Is Iron Deficiency So Common?
Dietary iron comes in two forms, heme iron and non-heme iron. Both can be useful to the body, but heme iron is much easier for the body to absorb. Just one problem: many of us don't eat a lot of foods that are high in heme iron, such as red meat, organ meats, and seafood.
This might sound like a fairly easy thing to fix, but there's another factor at play––the body's ability to absorb that iron once you eat it. Common supplements like calcium and zinc make it harder for the body to absorb iron, and of course, the gut microbiome plays a role as well. Certain types of beneficial bacteria, including S. thermophilus, increase the amount of iron your body absorbs, while certain unfriendly strains decrease it.2
If your gut microbiome is weighted towards those inhospitable strains, your body's going to have a hard time getting the iron it needs, even if you're loading up on red meat and iron supplements. (This means that iron supplements may not be effective until you populate your gut with the bacteria that increase your ability to absorb all the iron you're consuming.)
Finally, low iron levels are often caused or exacerbated by a few other factors, including menstruation, pregnancy, and breastfeeding. Women who are menstruating lose iron every month in their menstrual blood (this can be more of a problem in the case of heavy periods); pregnant women need more iron because their bodies are making about half again their normal amount of blood; and nursing women need more because they're passing some of their iron to the baby through their breast milk.3
5 Warning Signs That Your Iron Levels May Be Too Low
1. You're tired all the time, and you can't seem to think clearly.
Feeling run down is one of the most common signs that your iron levels are too low––remember, iron helps your red blood cells move oxygen around, so if you don't have enough of it, your cells aren't getting the fuel they need to function properly. This can translate into that whole-body, "can't shake it even after a couple of days in bed" type of tired.
Similarly, if you find yourself constantly struggling to focus, or slipping up when it comes to remembering common words, it could be that you're experiencing brain fog related to low iron levels. Too little iron can mean that your brain isn't getting the oxygen it needs, or that certain key neurotransmitters aren't being produced because your enzymes don't have the iron they need to make them.
2. Something strange is going on with your skin, hair, and nails.
Ever wonder why red blood cells are red? It's because of the iron they contain. Just like the iron in rust (or iron oxide) gives it its characteristic color, the iron in your red blood cells gives them that dark red color. If you don't have enough iron, the cells become smaller and paler, which can leave your skin looking washed out or yellowish. This can be hard to see if you're already naturally pale, so try looking at your tongue for a better indicator: if it's paler than normal, it could be that you're not getting enough iron.
Plus, if your hair and nails aren't getting the oxygen they need to grow, they can start to become brittle and weak. While it's natural to lose some hair every day, if you're losing a lot and it's not growing back, chances are your iron levels are out of whack. Similarly, if your nails are always breaking or they look flat or indented, it’s a good idea to take a look at your iron status.
3. Your immune system is out of whack.
Iron plays a key role in supporting the functioning of your immune system, so if you seem to catch every little thing that goes around, it could be that your iron levels are too low (the level of iron in your body has an effect on how your cells respond to possible threats).4
As we mentioned previously, there's also a direct connection between your iron levels and the health of your gut microbiome: the more in balance your microbiome is, the better you're able to absorb iron. Similarly, too high or too low iron levels can encourage the growth of undesirable bacteria, which can then lead to a reduction in your iron absorption. And of course, your gut microbiome is intricately linked to your immune system, so it's well worth looking into both the health of your microbiome and your iron levels as a preventative measure, even if you're feeling fine right now.5
4. Your hormones are all over the place.
Along with its role in enzyme reactions, iron also helps the body maintain balanced hormone levels––remember, it's a key player in the production of many important neurotransmitters, including GABA (which helps you regulate your response to stress), and thyroid hormones, among others.6,7 Be sure to consider your iron levels if you're experiencing changes in your weight, blemishes on your skin, or mood swings, as these are all common occurrences when your hormones become unbalanced.
5. You can't get enough ice.
This might sound like a weird one, but it's true: if your iron levels are too low, you're likely to start craving non-food things you normally wouldn't eat, including ice, dried pasta, chalk, or even dirt! Researchers aren't entirely sure why this happens, but it's really common in those with iron deficiency, so if those ice cubes start looking extra tasty, it's a good bet that there's something going on with your iron.8
How to Normalize Your Iron Levels
• Get tested by a doctor to see where things stand.
Before you start reaching for the iron supplements, get in touch with your doctor to make sure that you actually have an iron deficiency. Having too much iron in your body can be just as dangerous as having too little, so you don't want to accidentally over-supplement. Your doctor will likely recommend a serum ferritin test, which is a way of seeing how much ferritin (an iron-containing protein) is in your blood.
• Increase your dietary iron and match foods.
If it does turn out that your iron levels are too low, try to fix the problem with changes in diet before looking for a supplement. While iron supplements can be very effective, they're often made with a type of iron that's not natural for the body. And since your body has a limited capacity for excreting iron, this can mean that you end up with a build up of this less-than-ideal iron, especially if you're overdoing it with supplements.
Instead, increase your intake of iron-rich foods. Red meat, organ meats, poultry, fish, and shellfish are all good sources of heme iron (remember, that's the one that's easiest for your body to absorb), and lentils, egg yolks, sesame seeds (hello, tahini!), white beans, chickpeas, and blackstrap molasses all contain non-heme iron.
To get the best results, try food matching. Certain foods, when paired together, increase the amount of iron your body absorbs: for instance, when you eat foods that contain non-heme iron with foods that contain heme iron, your body is better able to absorb the non-heme iron than it would if you ate those foods on their own.
Similarly, vitamin C increases the amount of iron your body absorbs from food, so consider eating iron-rich foods along with citrus fruits or dark green veggies, which tend to be good sources of vitamin C. Of course, the opposite applies too, so do what you can to avoid substances that limit your iron absorption, particularly supplements that contain calcium (including antacids) and zinc.
• Use supplements appropriately.
Sometimes it's impossible to get the amount of dietary iron you need from the foods you eat, in which case a supplement can help. Do your research and work with your doctor to find the best iron supplement for your particular health needs that's not going to flood your system with too much iron––remember, having too much iron in your body is just as bad as having too little, and it's relatively easy to accidentally end up with too much if you're taking a high-dose supplement.
You may also want to consider taking other supplements that can help your body absorb the iron it's already getting, like vitamin C or a premium probiotic like PRO-15, which contains S. thermophilus, a specific bacterial strain that increases your body's iron absorption.
Iron plays such a critical role in your health that it's well worth keeping an eye on your iron levels, whether you're currently seeing any of these five signs or not. Now that you know what to be on the lookout for, make your nutritional health something you regularly check in on––and you might just find that those lingering issues resolve themselves with a little shift in diet.
1. Miller, J.L. (2013). Iron Deficiency Anemia: A Common and Curable Disease. Cold Spring Harbor Perspectives in Medicine 3(7). doi: 10.1101/cshperspect.a011866
2. Deschemin, J-C., Noordine, M-L., Remot, A., Willemetz, A. . . . Nicolas, G. (2015). The Microbiota Shifts the Iron Sensing of Intestinal Cells. The FASEB Journal 30. doi: 10.1096/fj.15-276840
3. Hytten, F. (1985). Blood Volume Changes in Normal Pregnancy. Clinical Haematology 14(3).
4. Cherayil, B.J. (2011). The Role of Iron in the Immune Response to Bacterial Infection. Immunologic Research 50(1). doi: 10.1007/s12026-010-8199-1
5. Cherayil, B.J., Ellenbogen, S., Shanmugam, N.N. (2013). Iron and Intestinal Immunity. Current Opinions in Gastroenterology 27(6). doi: 10.1097/MOG.0b013e32834a4cd1
6. Kim, J. and Wessling-Resnick, M. (2014). Iron and Mechanisms of Emotional Behavior. The Journal of Nutritional Biochemistry 25(11). doi: 10.1016/j.jnutbio.2014.07.003
7. Eftekhari, M.H., Keshavarz, S.A., Jalali, M., Elguero, E. . . .Simondon, K.B. (2006). The Relationship Between Iron Status and Thyroid Hormone Concentration in Iron-Deficient Adolescent Iranian Girls. Asia Pacific Journal of Clinical Nutrition 15(1).
8. Khan, Y. and Tisman, G. (2010). Pica in Iron Deficiency: a Case Series. Journal of Medical Case Reports 4(86). doi: 10.1186/1752-1947-4-86
Rachel Allen is a writer at Hyperbiotics who's absolutely obsessed with learning about how our bodies work. She's fascinated by the latest research on bacteria and the role they play in health, and loves to help others learn about how probiotics can help the body get back in balance. For more ideas on how you can benefit from the power of probiotics and live healthier days, be sure to subscribe to our newsletter. To learn more about how a healthy microbiome can enrich your life, subscribe to our newsletter.