Iron is a mineral that plays many roles in the body and is essential for growth and development. Iron is used to make hemoglobin in the body (hemoglobin is a protein found in red blood cells). Hemoglobin’s role is to carry oxygen from our lungs to other parts of the body.
Iron deficiency is reported by 60-80% of people with inflammatory bowel disease and could be due to multiple factors. This could be due to:
- Decreased food intake
- Malabsorption of nutrients
- Blood loss
- Frequent diarrhea
Note: iron deficiency is when total iron levels are low. Iron deficiency anemia is when total iron levels are severely low that they affect the body’s ability to produce red blood cells (also called erythropoiesis).
Due to a large percentage of those with IBD being iron deficient and the fact that IBD is a malabsorptive disease, iron supplementation is often used to bring levels to an optimal range. Always discuss supplementation with your healthcare provider to determine what is best for you and to assess any potential drug/nutrient interactions.
RDA of Iron
RDA stands for Recommended Dietary Allowance and is the average daily dietary intake sufficient to meet nutrient requirements for most healthy individuals.
The UL (Upper Limit) is also noted in the graph below to show that there is an amount of a nutrient that the body can intake per day without adverse health effects.
| Age | RDA | UL (Upper Limit) | |
| Women | Men | ||
| 0-6 months | 0.27 mg (AI) | 40 mg | |
| 7-12 months | 11 mg | 40 mg | |
| 1 – 3 years | 7 mg | 40 mg | |
| 4 – 8 years | 10 mg | 40 mg | |
| 9-13 years | 8 mg | 40 mg | |
| 14-18 years | 15 mg | 11 mg | 45 mg |
| 19-50 years | 18 mg | 8 mg | 45 mg |
| 51+ years | 8 mg | 45 mg | |
| Pregnancy | 27 mg | 45 mg | |
| Lactation | 9 mg (10 mg for <18 years) | 45 mg | |
As you can see, needs vary throughout the lifespan. Vegans and vegetarians require higher daily levels of iron as well due to the fact that plant-based sources of iron are not as readily absorbed by the body as animal sources.
4 things you might be doing wrong with iron supplementation
- Consuming antacids or calcium rich foods/supplements soon after taking your iron supplement.
- Avoid tea and calcium supplements/foods 2 hours pre/post an iron rich meal/supplement
- Drinking coffee or tea with your iron supplement.
- Avoid coffee and tea 2 hours pre/post an iron rich meal/supplement
- Not pairing iron rich foods with a source of vitamin C
- Vitamin C helps with iron absorption. Kiwis, peppers, oranges, strawberries, and tomatoes are all sources of vitamin C. Consider adding kiwi or strawberries to an iron-fortified breakfast cereal, a tuna sandwich with pepper strips on the side, or a lentil and bean tomato chili to pair iron and vitamin C together.
- Not using the most absorbable form of iron in your supplement.
- We often recommend iron bisglycinate as it is not only highly absorbable, but it’s also gentle on the intestines and less likely to cause unwanted GI side effects
Food Sources of Iron
Often in IBD, food sources are not enough to increase iron due to decreased absorption and increased inflammation – which is why supplementation is often recommended. However, consuming iron rich food sources is still a great thing to implement. Check out the chart below for some examples.
| Food Item | Amount of Iron |
| Tofu | 13.2 mg/cup |
| Soy Beans | 9.9 mg/cup |
| Fortified Cereal | ~8-10 mg/cup |
| Black Olives | 8.5 mg/cup |
| White Beans | 7 mg/cup |
| Lentils | 6.6 mg/cup |
| Spinach | 6 mg/cup |
| Tempeh | 4.5 mg/cup |
| Swiss Chard | 3.9 mg/cup |
| Dark Chocolate | 3.4 mg/oz |
| Quinoa | 3 mg/cup |
| Prune Juice | 2.9 mg/cup |
| Raw cacao powder | 2.3 mg/1 oz. |
| Sweet Potatoes | 2.2 mg/large potato |
| Acorn Squash | 2 mg/cup |
| Canned Sardines | 2 mg/3 oz. |
| Tuna | 1.4 mg/3oz |
Nuts and seeds are also great sources of iron, especially sesame seeds and pumpkin seeds. If you are building your tolerance for nuts/seeds, start with nut butters first 🙂
Don’t forget to pair the above foods with with a source of vitamin C (squeeze of lemon juice, kiwi, orange, peppers, strawberries) to enhance absorption! 😉
If levels still aren’t increasing, here’s what to do next
Upon iron supplementation, people can start to feel the effects of it working within 3-7 days. However, it can take up to 2 months of consistent supplementation to see a rise in levels of hemoglobin to the normal range.
If you do not feel any difference upon consistent iron supplementation, here are a few other things to discuss with your healthcare provider:
- Get your inflammatory markers checked
- If there is chronic inflammation in the body this may prevent your body from using stored iron
- Try taking your iron supplement every other day. Studies have shown that alternate day supplementation can increase iron absorption
- This is because when iron supplements are taken (and when inflammation is present) hepcidin is elevated which then decreases iron absorption. Hepcidin helps to control the amount of iron the body uses
- Consider cooking with cast iron cookware more as this can be an easy way to add iron to a meal or try out the Lucky Iron Fish!
- Reassess common things that can interfere with iron absorption
- When are you taking you iron supplement? Are you taking it away from calcium rich foods/products and coffee/tea?
- Are you taking your iron supplement with any other medications that may interfere with absorption? PPIs are one type of medication that can affect iron metabolism
- More iron is utilized during heavy menstruation, pregnancy, bleeding, increased inflammation, and working out – please chat with your healthcare provider to see if dosing needs to be adjusted to your unique situation
Optimizing iron levels can take some time, but is possible with the right approach and knowing how the information found in this article can play a vital role. If you are looking for further support on enhancing your iron levels and optimizing your IBD nutrition treatment plan, let’s chat!