What Enhances and Inhibits Iron Absorption and Why Your Iron Levels Are Low; What to Look for in Iron Lab Markers
Examples of iron lab resuls and what they mean
How to Enhance Iron Absorption
Iron deficiency is one of the most common nutrient deficiencies worldwide, with an estimated 20% of the world’s population deficient. In developed countries, roughly 10% have iron deficiency. Iron is vital for human life and involves oxygen transfer, mitochondrial energy generation, DNA synthesis, and as a cofactor in various enzyme reactions. (1)
The average diet supplies 10-20 mg. of iron daily, but only 1-2 mg may be absorbed. Seventy-five percent of that iron is utilized in hemoglobin, 10-20% is stored as ferritin, and 5-15% is utilized in other biochemical bodily processes. (2, 3)
Iron deficiency can occur for a number of reasons, such as:
poor dietary intake
poor absorption
blood loss
endurance exercise
low stomach acid (HCL)
The most common symptom of iron deficiency is fatigue and lethargy.
Labs that should be run to determine iron status are Complete blood count (CBC), ferritin, iron, TIBC, and % saturation.
Understanding why your iron levels are low before adding foods or supplementing is important. DO NOT supplement with iron if lab test results indicate your iron levels are not low. Many people do not pay attention to the iron in their supplements, such as their multivitamins. Be sure to read the back label on your supplements.
There are two types of food-sourced iron: heme and non-heme. Heme iron comes from animal sources such as red meat, fish, and poultry. Non-heme is found in plants, fruits, molasses, vegetables, nuts, seeds, and grains. Each iron source has a distinct absorption pathway.
How to Increase Iron Absorption
Take vitamin C with iron-rich foods or with an iron supplement. Vitamin C will enhance iron extraction from food or supplements. For instance, while I prefer an orange over OJ, studies have indicated that a glass of OJ with an iron-rich meal increased heme iron absorption by 2.5 times. (4, 5)
Other foods that will increase iron absorption include:
fermented foods like pickels, sauerkraut, kefir and yogurt
garlic
probiotics
cook in a cast iron skillet for iron absorption from the pan
Foods that will decrease absorption include:
Phytate-rich foods such as beans and legumes can inhibit iron absorption up to 50%
Black tea, coffee, and chocolate can inhibit iron absorption by 50 to 90%
Calcium supplements and calcium-rich foods-but small amounts of calcium-rich foods do not significantly affect iron absorption.
Tumeric/curcumin-take this supplement away from iron
Soy products
(2, 3, 8, 6, 7, 9, 10, 11)
How to Supplement with Iron
Take iron on an empty stomach if you can tolerate it this way, at least 30 minutes before or 2 hours after a meal.
Take away by 2 hours from medications.
Take with vitamin C in a 10:1 ratio. For example, if your iron dose is 10 mg, take 100 mg of vitamin C. If your iron dose is 25 mg, take 250 mg of vitamin C with it.
Wait 90 days before re-testing iron levels. If no change, look at the iron deficiency root causes. For instance, are you taking a proton pump inhibitor medication? If so, learn how to support optimal stomach acid levels without medication. (Do not go off your PPI medication cold turkey, or it can induce rebound effects, and discuss with the prescribing doctor first).
Chelated iron may be preferred to avoid constipation with iron supplements.
Sources
DeLoughery TG. Iron Deficiency Anemia. Med Clin North Am. 2017 Mar;101(2):219-332.
Hawula Zj et al. Therapeutic Advances in Regulating Hepcidin/Ferroportin. Pharmaceuticals (Basel). 2019 Dec;12(4):170.
Katsorou A and Pantopoulos K. Hepcidin Therapeutics. Pharmaceuticals (Basel). 2018 Dec:11(4);127.
Teucher B et al. Enhancers of iron absorption. ascorbic acid and other organic acids. Int J Vitamin Nutr Res. 2004 Nov: 74(6)-403-419.
Hallberg L et al. The role of vitamin C in iron absorption. Int J Vitamin Nutr Res Suppl.1989 :30 ;103-108.
Piskin E etal. Iron Absorption: Factors, Limitations and Improvement Methods. ACS (American Chemical Society) Omega. 2022:7(24);204410-20456.
Dasa F and Abera T. Factors Affecting Iron Absorption and Mitigation Mechanisms: A review. International Journal of Agricultural Science and Food
Milman NT. A Review of Nutrient and Compounds, Which Promote or Inhibit Intestinal Iron Absorption. Making a Platform for Dietary Measures That Can Reduce Uptake in Patients with Genetic Haemochromatosis. J Nutr Metab, 2020: 7373498.
Zijp IM et al. Effect of tea and other dietary factors on iron absorption. Crit Rev Food Sci Nutr. 2000 Sep:40(5); 371-98.
Laine F et al. Curcuma decreases serum hepcidin levels in healthy volunteers: a placebo-controlled, double-blind cross over study. Fundam Clin Pharmacol. 2017 Oct:31(5);567-573.
Smith TJ and Asher BH. Iron Deficiency Anemia Due to High Dose Tumeric. Cureus. 2019 Jan:11(1);e3858.
Iron Tests and What a Full Panel Can Reveal
It is important to order an iron panel, especially if you have iron overload in your family, such as a genetic disorder, hemochromatosis, or if you are experiencing chronic fatigue and lethargy. You may also want to order an iron panel if you have heavy menstrual cycles, take a medication that reduces acid levels, take a T4 medication for your thyroid, have active ulcers, are an endurance athlete, or drink alcohol excessively.
For instance, if your ferritin is low based on functional ranges, and your serum iron is good or high with a TIBC in the mid-300s, this may indicate an active MTHFR mutation or high heavy metal bodily presence.
A pattern with high ferritin and less than optimal iron (functional ranges) may suggest inflammation. A deeper dive into this may indicate thyroid, gluten sensitivity, or other inflammatory issues.
Take a look at your recent labs-did they run an iron panel? Did they even run a serum iron test? Do you think they should run a full iron panel on you next time? Why or why not?
The problem, to me, seems to be that drs don't run "panels" of anything. They run the 1 single test they've been trained to run. Period. When you ask them to run additional testing they tell you it's not needed. OR you tell them what additional testing you wish to have run, they become belligerent, reinforce that they KNOW what they're doing, and you need to stop reading things on the internet! (How dare you, you ignorant scum!)
I went in with pages of back-up, which was glanced at and tossed down. Be prepared to stand your ground, describe your symptoms, that are also on the pages not looked at, and DON'T back down! I described one odd symptom that is a symptom of low thyroid, I was told that she had the same symptom. I told her maybe she should have her thyroid checked. The tests requested were run and, yes, I had low thyroid.