Iron deficiency anemia is something (unfortunately) near and dear to my heart. I’ve struggled with this condition on and off since my early teenage years and it can often fly under the radar until it becomes a serious problem!
There are also billions of people around the world with iron-deficiency anemia. (1)
The good news is that it’s a relatively easy fix, from a nutrition standpoint!
The biggest challenge is the possibility of unwanted gastrointestinal (GI) side effects which often follow iron supplementation, as well as a few key logistics to consider in terms of iron’s interactions with certain other nutrients and medications.
In this article, I’ll share my insights and perspectives on iron deficiency anemia in the simplest way possible so you can feel more confident navigating this condition from a clinically sound, holistic nutrition standpoint.
Disclaimer: This article was written for general educational purposes and should complement/enhance (but not replace) medical and nutritional advice from your healthcare team. Consult with your doctor and registered dietitian for customized recommendations tailored to your bio-individual needs.
(Updated March 13, 2025)
Table of Contents
What is anemia?
Anemia is a condition in which our blood is not carrying enough oxygen to the rest of our body, either because we don’t have enough total red blood cells, our red blood cells are too small in size, or we don’t have enough hemoglobin (an iron-rich protein that is carried by our red blood cells).
If we don’t have enough iron in our body, we can’t make enough hemoglobin, and without enough of that…well, let’s just say it’s no picnic!
When our hemoglobin levels are low, our cells aren’t getting enough oxygen to do everything they need to do.
Types of anemia
There are multiple different types of anemia, depending on the underlying nutrient deficiencies impacting your red blood cell production.
The most common types of anemia include:
- Iron deficiency anemia
- Sideroblastic anemia
- Thalassemia
- Lead toxicity anemia
- Anemia of chronic disease (secondary to cancer, kidney disease, etc.)
- Blood loss anemia (secondary to heavy menstrual cycles, injury-induced blood loss, GI-induced blood loss, etc.)
- Hemolytic anemia
- Aplastic anemia
- Anemia from bone marrow infiltrative disorders
- Sickle-cell anemia
- Megaloblastic anemia (induced by vitamin B12 deficiency)
- Non-megaloblastic anemia
For the purposes of this article, we’ll zoom in on iron deficiency anemia.
What is iron-deficiency anemia?
Iron-deficiency anemia is a condition in which we have low blood levels of iron (for one reason or another) to the point where it has compromised our hemoglobin production, ultimately resulting in a decreased oxygen supply to all of our cells.
Common symptoms of iron-deficiency anemia
- General weakness/fatigue
- Pale skin
- Rapid heart beat
- Light-headedness
- Dizziness
- Shortness of breath
- Reduced exercise endurance
- Brittle nails
- Ridged or spoon-shaped nails
- Hair loss
- Cold hands and feet (poor circulation)
Did you know… Pre-menopausal women need more than DOUBLE the amount of iron from food compared to men!
A healthy adult female (age 18-50) on average requires about 18 milligrams daily, while non-mensurating people within the same age bracket need only need ~8 milligrams of iron per day for healthy red blood cell maintenance. (2)
Note that if you have iron deficiency anemia, your daily iron needs may be considerably higher for repletion purposes.
8 things you should know if you have iron-deficiency anemia
All iron is NOT created equal!
There are two types of iron: HEME and NON-HEME.
We absorb about 15% of heme sources of iron, while we only absorb 3-8% of non-heme iron. (3)
Heme iron
Heme iron comes from animal food sources such as red meat, liver, and eggs.
Note that heme iron is naturally more “bioavailable” (better absorbed and used by our body) compared to non-heme iron.
Non-heme iron
Non-heme iron comes from plant sources such as tofu, dark leafy greens, beets, beans, dates, cacao, iron-fortified breads, iron-fortified cereals, and iron-rich herbs.
Supplemental iron is also considered non-heme.
Iron and vitamin C make a great team
Combining iron supplements and/or plant sources of iron (non-heme) with vitamin C will significantly increase the amount of iron that gets absorbed by your body.
(This is especially important for vegans and vegetarians, since the majority of your food sources of iron are non-heme!)
A few examples are adding berries, peppers or citrus to a spinach salad, combining iron-rich herbs with vitamin C-rich herbs, or even just taking your iron supplement with a small glass of pineapple juice or orange juice instead of water.
Recommended reading:
- The Best Herbal Tea for Iron Deficiency Anemia
- 6 Blood-Building Herbs for Iron Deficiency
- 11 Herbs High in Vitamin C (Round-Up & Guide)
- Iron-Rich Cherry Cacao Smoothie
Iron and calcium clash
If you’re trying to increase your iron levels, don’t mix your iron-rich food or supplement with a glass of milk or calcium-fortified food.
(Note that this is especially true for iron-rich cereals which often get mixed with a calcium-rich milk or milk substitute!)
This is because iron and calcium compete for the same absorption sites in the gut, and will cancel each other out if you’re consuming them at the same time.
Milk and milk substitutes aside, remember to also be mindful of other hidden calcium sources like multivitamins, calcium-fortified orange juice, calcium chews, and even certain antacids such as Tums which are made of calcium carbonate.
Iron can interfere with certain medications.
If you’re taking iron supplements, make sure to take them at least a few hours apart from antibiotics, Mycophenolate Mofetil (CellCept ®) or any meds used for treating any of the following:
-
- Osteopenia/osteoporosis
- Thyroid problems
- Parkinson’s disease
- Wilson’s disease
- Antacids and proton pump inhibitors (may significantly reduce your iron absorption in the gut)
Iron supplements can be known to cause upset stomach.
The most common side effects of iron supplements (even when prescribed by a doctor) are nausea and constipation.
- Recommended reading: IBS and Iron Deficiency: Uncovering the Links
How to take iron pills without getting sick
Don’t take iron on an empty stomach!
I always recommend taking iron with a meal or snack to reduce and minimize any potential unpleasant side effects.
(Just remember not to mix iron with calcium-rich foods/supplements and to instead combine it with a source of vitamin C!)
Try incorporating probiotics (from food or supplements) into your routine.
Probiotic foods and/or probiotic supplements may potentially help to enhance your tolerance to iron supplements as well as support better iron absorption in your gut.
If you’re into German sauerkraut, you would love my traditional lacto-fermented sauerkraut recipe!
Recommended reading:
Consider functional foods for constipation
If you’re prone to constipation from the iron supplements, consider integrating a functional food (such as prunes or kiwi) into your regimen to reduce symptoms of constipation.
Recommended reading:
- The Best Smoothie for Constipation Relief (Recipe)
- 8 Health Benefits of Prunes and How They Impact Your Nutrition
- 9 Ways Eating Kiwi Benefits the Body, According to Registered Dietitians
The lower our iron levels, the higher our iron absorption
Our bodies are smart and they know what they need!
Research shows that people with lower iron levels tend to have exponentially greater iron absorption rates, or “iron-binding capacity”.
You might also find yourself craving more spinach salads or red meat (or in cases of PICA, you could even crave ice or non-food substances like dirt, clay or chalk).
Synthetic iron may feed bad (dysbiotic) bacteria
Proceed with caution when it comes to iron supplements, since iron has been found to alter our gut microbes in ways that promote symptoms of irritable bowel syndrome (IBS). (4)
When taking iron supplements, you may want to increase your probiotic intake especially if you have any kind of bacterial infection or are prone to “dysbiosis”.
Cast iron skillets can help increase iron content of foods
Cooking acidic foods (such as tomatoes or tomato sauce) in a cast iron skillet is one of my favorite ways to boost iron intake quickly and easily! (5, 6)
However, this may not always be enough as a stand-alone intervention to restore healthy iron levels in your body.
ALWAYS consult a doctor or dietitian before starting iron supplements
It’s surprisingly easy, and very dangerous, to overdose on iron.
“Safe” levels of iron will be completely different depending on your blood levels of hemoglobin, so you need to leave your dosing up to a medical professional.
Overdosing on iron can lead to nausea/vomiting/diarrhea, liver failure, and even death. Use only as directed!
Recap & final thoughts
Iron deficiency anemia is one of the most common types of anemia and medical conditions worldwide, especially among menstruating females.
While there are many ways to resolve iron deficiency anemia from a nutrition standpoint, t’s important to understand the difference in bioavailability of heme versus non-heme iron sources.
You’ll also want to consider the ways in which iron interacts with nutrients such as vitamin C and calcium (for better or worse).
Taking iron supplements may be better tolerated and more effective if you’re taking the supplements with food and a vitamin C source, a few hours apart from calcium.
Note that iron supplements can feed dysbiotic gut microbes, worsening the likelihood of IBS symptoms.
Integrating probiotic supplements and/or probiotic-rich foods into your regimen could potentially help reduce or minimize unwanted side effects of iron supplements such as nausea and/or constipation.
Functional foods for constipation (such as kiwi, prunes, chia seeds, and/or ground flax seeds) may also help minimize or alleviate unwanted symptoms of constipation.
Cooking acidic foods in a cast iron skillet has been shown to significantly increase the iron content in foods, but this may or may not be enough as a stand-alone intervention.
Always make sure to consult 1-1 with your doctor and a registered dietitian to make sure you aren’t overdosing on iron supplements, since this can be dangerous and toxic to your liver.
Sharing is caring!
If you found this article helpful, please SHARE IT so others suffering from iron deficiency anemia can learn and become empowered to make more informed choices on their health journey!
XX – Jenna
