Should you take iron supplements?
Welcome to the Nugent report, I’m Dr. Steve Nugent. On this podcast I’ll be addressing questions related to iron supplementation, including who should take iron supplements, food sources of iron, how much is required daily and how much is too much. I’ll also address pregnancy and prenatals as well as lactation. Finally, what are the risks of taking too much iron.
Several of my subscribers have written in to ask if they should take iron supplements. The short answer is yes if you need it and know if you don’t. Perhaps that sounds too simple, but there is much more you need to know. The fact is, iron is potentially lethal.
Iron is an essential nutrient and that means your body must have it, but your body is incapable of making it therefore it must be obtained from food or food supplements.
Unlike water-soluble vitamins that are flushed from the body if taken in excess, iron is a storable nutrient. If too much is stored (based on body weight), illness and death can result. For this reason, throughout my career I have always been cautious about iron supplementation and typically recommended against it in multis opting for proper diet recommendation or medical intervention where required. So, the answer is not as simple as it seems.
Most people have probably heard the phrase, “figures don’t lie, but liars use figures”. That’s a bit harsh perhaps for this subject because in many cases it’s not a question of a deliberate lie, but rather innocent misunderstanding or misinterpretations.
On the one hand, the most common mineral deficiency globally is iron, but that’s a bit misleading because in modern countries iron deficiency is not common. The total global figures take into account the populations of developing countries that may have insufficient food sources of iron.
According to the World Health Organization there are just over 1.6 billion people on planet Earth who are deficient in iron.(1)When that statistic was last updated by the WHO in 2008 there were fewer people on planet Earth, but the general averages remained the same today, because world food source conditions remain approximately the same.
According to the World Health Organization, preschool children make up 47.4% of the total and pregnant women make up 41.8% of the total, of people included in the total number of those deficient in iron. (1,2) Pregnancy is not a chronic condition and preschool children grow up. The other significant issue is menstruating females, which I’ll address shortly. When you examine the figures closely you see that less than 25% of people worldwide need iron supplementation in fact the World Health Organization says its 24.8%. Some need iron chronically but most do not. Turn that around and look at it from the other direction and it will tell you that just over 75% of the world’s population does not need iron supplementation daily and because iron in excess is extremely dangerous, that is the first and most important part of the argument against including iron in daily multiple vitamin mineral products.(1,2)
More is not always better. Too much iron poses a very serious danger. From 1980 to 1991 for example, iron in children’s dietary supplements was the leading cause of death by poisoning in the US for children six years of age or younger. Children’s chewable supplements were cute and tasty made with synthetic sweeteners. The childproof caps proved not to be childproof in all too many cases. (3) In 2020, the public was given a great deal of information about zinc and how important it is; however, the public was not told that too much iron can actually cause zinc anemia. I’ll come back to that idea shortly. For now, let’s examine the world health organization figures for better understanding.
If you break down the numbers according to age, gender, pregnancy, and available food sources, iron deficiency in modern countries with sufficient available food sources is rare without an accompanying medical condition. If you have an accompanying medical condition you should be under medical supervision not self-treating.
Menstruating females do experience significant loss of iron during menstruation but in most cases proper diet selection can replace the necessary iron. In countries where those food sources are either scarce or unavailable it does become a chronic health issue, and the supplementation is required.
Menstruation under healthy conditions, occurs approximately once every 28 days and may last 2 to 7 days but its typically 3 to 5 days of blood loss. The rest of the month, a woman’s blood supply can be restored through dietary selection in most cases. (4,5) The average woman loses between 30 to 180 ml, with an average of 80 ml for a normal menstrual period (6)
According to scientific study, approximately 90% of women lose 1.4 mg or less of iron per day through a normal menstrual cycle, eating 3 ounces of dark chocolate gives you 7 mgs. (6,7,5) With these stats in mind only women with other medical complication or women who live in regions with insufficient food sources of iron need iron supplementation. One other exception would be vegetarians and vegans which I will cover shortly.
Then there is the genetic factor to take into consideration. According to the US National Institutes of Health, National Genome Research Institute, approximately 10% of Earth’s population have a gene for hereditary hemochromatosis, also known as iron overload disease. The people most likely to carry this gene are Caucasians of Northern European descent, but its seen in other races as well. Having the gene however is not a guarantee that an individual will suffer from the disease.
Hereditary hemochromatosis is typically abbreviated as HH, and the gene in question is called HFE. Most cases of hemochromatosis result from a common mutation in the HFE gene, known as C282Y, but other mutations have also been identified. (8)
A child who inherits two copies of the mutated gene (one from each parent) is highly likely to develop the disease, but it’s still not a certainty. Those who carry two copies of the mutated gene but are asymptomatic are referred to as silent carriers. Those individuals of course can still pass the gene onto their children.
If two parents are silent carriers it is estimated that there is an approximately 25% chance of the child inheriting two copies of the defective gene and developing the disease. According to the experts, silent carriers may remain asymptomatic throughout their life unless they develop diabetes or alcoholism. Individuals with hereditary hemochromatosis require medical intervention. Without proper medical intervention individuals with hemochromatosis can develop diabetes, heart disease, cirrhosis of the liver, liver cancer and joint disease and even organ failure. (8) If a person suffers from hereditary hemochromatosis, they require medical care plain and simple, and the last thing you want to do is have them take a multiple vitamin mineral product fortified with iron.
People with iron anemia, and abnormal menstruation also need to be under medical supervision. Approximately 75% of the population will do fine with iron from food and simply don’t need iron supplements. (1). So, in my view, the majority of the world should not be supplementing iron unless they need it and most of those individuals need to be under medical supervision. They should not be self-treating!
Then we come to the complications that can be caused by creating imbalances in your biochemistry.
In nutritional biochemistry there are catalysts, synergist’s and antagonists. As I have been saying for more than 40 years in my lectures, “the key to wellness is balance” and the body is always attempting to maintain homeostasis which is simply a fancy way of saying balance. If your iron levels go up too high, you can drive down your zinc and if your zinc levels go to high it can drive down your copper. It’s important that diet and dietary supplements are part of an intelligently designed daily health plan with the goal of maintaining healthy balance. (9,10,11)
The recommended dietary allowance of iron is listed below so I won’t go into detail here. It’s a common myth that females always need more iron than males, this is incorrect. Females between the ages of 14 and 50 as well as women who are pregnant or lactating do require more iron than males at the same age.
However, the rest of the time males and females have equal requirements as an example, between the ages of 7 and 12 months, males and females both require 11 mg of iron daily which necessary for cognitive development as well as other factors. Between the ages of 1 and 3, the iron requirements are reduced to 7 mgs daily. Growth and development requirements again increase between the ages of 4 and 8 years when the minimum daily recommendation then goes up to 10 mg daily. Go to my website drnugent.com for more details.
Table 1: Recommended Dietary Allowances (RDAs) for Iron 
|Birth to 6 months||0.27 mg*||0.27 mg*|
|7–12 months||11 mg||11 mg|
|1–3 years||7 mg||7 mg|
|4–8 years||10 mg||10 mg|
|9–13 years||8 mg||8 mg|
|14–18 years||11 mg||15 mg||27 mg||10 mg|
|19–50 years||8 mg||18 mg||27 mg||9 mg|
|51+ years||8 mg||8 mg|
How much is too much?
You’ve heard me talk before on previous podcasts about the tolerable upper intake levels which is typically written as Uls. This is the maximum level that can be tolerated as identified by age and gender as well as pregnancy and lactation for any given nutrient. Refer to the table on drnugent.com for specifics, but for both male and female from birth through age 13 the maximum safe upper limit is 40 mg. From age 14 and older the maximum safe upper limit is 45 mg this is also considered the maximum safe upper limit for both pregnancy and lactation. You can consult the Food Nutrition Board for further details. As I’ve been saying for decades in my lectures, “more is not always better”.
Table 3: Tolerable Upper Intake Levels (ULs) for Iron 
|Birth to 6 months||40 mg||40 mg|
|7–12 months||40 mg||40 mg|
|1–3 years||40 mg||40 mg|
|4–8 years||40 mg||40 mg|
|9–13 years||40 mg||40 mg|
|14–18 years||45 mg||45 mg||45 mg||45 mg|
|19+ years||45 mg||45 mg||45 mg||45 mg|
What foods contain iron?
okay so now you might be thinking, what food sources you should be eating to get sufficient daily iron. A list of foods provided by the US Department of Agriculture’s Food data central is posted on drugent.com along with a transcript of this podcast. Many people are happy to see that dark chocolate is an excellent source of iron some people are less pleased to see that beef liver is also a very significant source of iron.
As is the case with a significant number of nutrients, animal products provide greater levels than vegetables. However, if you take the time to educate yourself properly and do intelligent food selection, you can live a very healthy life as a vegetarian. The problem however is that many vegetarians do not take the time or effort to properly study diet and food sources and as a result frequently come up deficient in a variety of nutrients. I had a significant number of patients when I was in practice who were either vegans or vegetarians. Almost universally the complaints and problems were the same. Deficiencies in iron, B12 and folic acid were most common but not exclusive.
Regardless of your dietary philosophy you’re first a person and then whatever other label you choose to wear. People regardless of their dietary philosophies tend to choose the foods they like to eat, and surveys show us that people tend to narrow their diets as a result. When it comes to healthy diet, variety is extremely important, and most people simply don’t do it.
I would point out one of the principal differences between vegans and vegetarians is that vegans tend to be highly disciplined and very aware of nutrition sources in food, whereas vegetarians more often than not have simply adopted a fad or a philosophy and do not take the appropriate steps to protect their health, even though they boast to their friends that they are smarter and have made healthier choices because they chose to be a vegetarian. So, vegetarians in general can often benefit from some education from vegans.
Animal protein and organ meat always contain iron, because iron is essential to live. When I say animal protein, I’m not just including land mammals but also seafood and fowl. Generally speaking, the redder the meat the higher the iron.
For the vegetarians, you’ll be happy to know that lentils, spinach, tofu and kidney beans also contain significant amounts of iron. So, it is definitely possible to maintain healthy levels of iron on a vegan or vegetarian diet, if you know how to select your foods correctly.
|Table 2: Selected Food Sources of Iron |
|Breakfast cereals, fortified with 100% of the DV for iron, 1 serving||18||100|
|Oysters, eastern, cooked with moist heat, 3 ounces||8||44|
|White beans, canned, 1 cup||8||44|
|Chocolate, dark, 45%–69% cacao solids, 3 ounces||7||39|
|Beef liver, pan fried, 3 ounces||5||28|
|Lentils, boiled and drained, ½ cup||3||17|
|Spinach, boiled and drained, ½ cup||3||17|
|Tofu, firm, ½ cup||3||17|
|Kidney beans, canned, ½ cup||2||11|
|Sardines, Atlantic, canned in oil, drained solids with bone, 3 ounces||2||11|
|Chickpeas, boiled and drained, ½ cup||2||11|
|Tomatoes, canned, stewed, ½ cup||2||11|
|Beef, braised bottom round, trimmed to 1/8” fat, 3 ounces||2||11|
|Potato, baked, flesh and skin, 1 medium potato||2||11|
|Cashew nuts, oil roasted, 1 ounce (18 nuts)||2||11|
|Green peas, boiled, ½ cup||1||6|
|Chicken, roasted, meat and skin, 3 ounces||1||6|
|Rice, white, long grain, enriched, parboiled, drained, ½ cup||1||6|
|Bread, whole wheat, 1 slice||1||6|
|Bread, white, 1 slice||1||6|
|Raisins, seedless, ¼ cup||1||6|
|Spaghetti, whole wheat, cooked, 1 cup||1||6|
|Tuna, light, canned in water, 3 ounces||1||6|
|Turkey, roasted, breast meat and skin, 3 ounces||1||6|
|Nuts, pistachio, dry roasted, 1 ounce (49 nuts)||1||6|
|Broccoli, boiled and drained, ½ cup||1||6|
|Egg, hard boiled, 1 large||1||6|
|Rice, brown, long or medium grain, cooked, 1 cup||1||6|
|Cheese, cheddar, 1.5 ounces||0||0|
|Cantaloupe, diced, ½ cup||0||0|
|Mushrooms, white, sliced and stir-fried, ½ cup||0||0|
|Cheese, cottage, 2% milk fat, ½ cup||0||0|
|Milk, 1 cup||0||0|
* DV = Daily Value.
Consult the U.S. Department of Agriculture’s (USDA’s) FoodData Central  for lists of foods and nutrient content.
Could I have an iron deficiency?
You might also be wondering if you are potentially at risk for iron deficiency. As is the case with many nutrients, vegans and vegetarians are always towards the top of the list of people who may experience mineral or vitamin deficiency. I say it in that order because minerals occur in very low levels in vegetable material generally speaking. Scientific study also shows us that even with minerals from food, the absorption rate and bioavailability is relatively low and we also know that the majority of people with the exception of vegans and vegetarians do not consume sufficient levels of vegetables or for that matter even fruits.
As I have already outlined, this potentially includes pregnant women, infants and young children, as well as women with abnormally heavy menstrual bleeding. Also, at risk are cancer patients, people who have had gastrointestinal surgery, people suffer from gastrointestinal disorders, patients with chronic heart failure and vegetarians.
With the exception of vegetarians, all the groups previously mentioned should be under medical supervision and not self-treating. I didn’t mention one of the obvious categories and that would be individuals who regularly donate blood. Obviously, they need to rebuild their blood supply by supplementing iron or increasing foods in their daily diet that contain iron.
It’s important in my view to spend some time discussing the issue of prenatal supplementation because I am frequently asked by women who only want to take natural supplements and as a result do not take the prenatal multiple vitamin mineral products that their doctors have prescribed. My strongest possible recommendation is that if a woman is pregnant, she needs to be under medical supervision and she needs to take a prenatal vitamin mineral supplement as directed by her physician. Do not, I repeat do not compromise with this.
If you examine a prenatal side-by-side with the average multi-you will see some obvious differences. A child’s life is literally at stake if mom does not provide sufficient nutrition to the fetus. There has been a great deal of discussion about folic acid deficiency and birth defects, but I’ve run into very few women who have been educated on the risk of low iron during pregnancy and lactation. There is a portion of the brain that requires iron to form. If a child in the womb is shortchanged on iron they will be shortchanged for life in terms of reaching their full cognitive potential! Low iron during pregnancy can also impair behavioral development. Don’t let that happen! (13-16)
The most common and obvious problem observed in women who have iron deficiency during pregnancy is premature birth and low birth weights (17)
The US National Health and Nutrition Examination Survey (NHANES) found that even in the US where food sources of iron are abundant, 18% of pregnant women were iron deficient. The need for iron approximately doubles each trimester. (18) Ladies take your prenatal’s as directed by your physician! No compromise, period, full stop!
I’m not going to spend the time to discuss natural versus synthetic in this podcast. I will do this in another future podcast. My subscribers know that they can trust me to give them objective validated information for their health. There is no science whatsoever (if you know how to read the science) that indicates that a prenatal would be dangerous and yes, they will contain synthetics. There is also a big misunderstanding as it relates to natural versus organic mineral supplements and absorption, in fact you will likely be surprised when you hear the facts. Once again I’ll cover this in another podcast but for now, ladies, take your prenatal as directed you will be doing a very significant favor for your child, not just to get them through the birthing process but literally for the rest of their lives.
There is a great deal more to discuss when it comes to the benefits and potential risks of iron supplementation, but this is a podcast not an encyclopedic reference. You now have the basics, and you know why throughout my career I have recommended against supplementing iron daily unless you fall into one of the categories previously mentioned. Virtually in all of those cases mentioned except two, the individuals who need iron supplementation should also be under medical supervision. If dietary supplementation is required than it needs to be done safely and effectively. Sometimes like it or not, this means you need to be under medical supervision.
Looking at global statistics it’s clear that more than 75% of the world’s population does not need iron supplementation and there is a potential risk with excessive iron intake, for this reason, iron supplementation as part of a general multiple vitamin mineral support program simply doesn’t make sense.
I hope you found this podcast enlightening and important for your health needs. Thank you for listening to this episode of the Nugent report. Until next time this is Dr. Steve Nugent, urging you to be safe, be sensible and be objective.
- World Health Organization
- de Benoist B et al., eds.Worldwide prevalence of anaemia 1993-2005. WHO Global Database on Anaemia Geneva, World Health Organization, 2008.
- Morris CC. Pediatric iron poisonings in the United States. South Med J. 2000;93(4):352-358.
- Mary-Jane N. Ofojekwu, FMLSCN, Ogbonnaya U. Nnanna, MLS, Charles E. Okolie, PhD, Lolade A. Odewumi, AMLSCN, Ikechukwu O. U. Isiguzoro, M.Sc, Moses. D. Lugos, M.Sc, Hemoglobin and Serum Iron Concentrations in Menstruating Nulliparous Women in Jos, Nigeria, Laboratory Medicine, Volume 44, Issue 2, May 2013, Pages 121–124, https://doi.org/10.1309/LMM7A0F0QBXEYSSI
- Hallberg L Högban AM Nilsson L Rybo G . Menstrual blood loss; a population study. Variation at different ages and attempts to define normality. Acta Obstet Gynecol Scand. 1966:45;320–321.
- Vander AJ World Health Organization (WHO) . Control of Nutritional Anemia with special Reference to Iron Deficiency. Report of an IAEA/USAID/WHO Joint Meeting. Publication no. 580. Geneva, Switzerland; 1975.
- Li J Gao Q Tian S Chen Y Ma Y Huang Z . Menstrual blood loss and iron nutritional status in female undergraduate students [in Chinese]. Wei Sheng Yan Jiu. 2011;40(2):204–205.
- Murray-Kolbe LE, Beard J. Iron. In: Coates PM, Betz JM, Blackman MR, et al., eds. Encyclopedia of Dietary Supplements. 2nd ed. London and New York: Informa Healthcare; 2010:432-8.
- Solomons NW. Competitive interaction of iron and zinc in the diet: consequences for human nutrition. J Nutr 1986;116:927-35.
- Whittaker P. Iron and zinc interactions in humans. Am J Clin Nutr 1998;68:442S-6S.
- S. Department of Agriculture, Agricultural Research Service. FoodData Central , 2019.
- Milman N. Iron in pregnancy: How do we secure an appropriate iron status in the mother and child? Ann Nutr Metab 2011;59:50-4. [PubMed abstract]
- Pavord S, Myers B, Robinson S, Allard S, Strong J, Oppenheimer C. UK guidelines on the management of iron deficiency in pregnancy. Br J Haematol 2012;156:588-600. [PubMed abstract]
- Pena-Rosas JP, De-Regil LM, Dowswell T, Viteri FE. Daily oral iron supplementation during pregnancy. Cochrane Database Syst Rev 2012;12:CD004736. [PubMed abstract]
- Scholl TO. Maternal iron status: relation to fetal growth, length of gestation, and iron endowment of the neonate. Nutr Rev 2011;69 Suppl 1:S23-9. [PubMed abstract]
- World Health Organization. Iron Deficiency Anaemia: Assessment, Prevention, and Control. World Health Organization, 2001.
- Mei Z, Cogswell ME, Looker AC, Pfeiffer CM, Cusick SE, Lacher DA, et al. Assessment of iron status in US pregnant women from the National Health and Nutrition Examination Survey (NHANES), 1999-2006. Am J Clin Nutr 2011;93:1312-20. [PubMed abstract]