Dietitian’s corner: Iron – why we need it and where to find it

By Carla Centola, RD

Everyone knows that iron is an essential nutrient, but simply eating foods that contain iron may not be enough, since there are many factors that affect absorption.

Why do we need iron?

Iron is essential for carrying oxygen via the red blood cells to the rest of our body, for producing red blood cells and hemoglobin for manufacturing certain hormones, for maintaining a robust immune system and for assisting in cell activity such as cell division. Low iron causes fatigue and tiredness, but it’s important to not have too high levels either.

Who is at risk?

Common risk factors for iron deficiency include (but are not limited to):

Signs and symptoms of iron deficiency:

If you have early-stage iron deficiency without anemia you may or may not have any symptoms. But, while some individuals with iron deficiency are asymptomatic, common signs and symptoms may include fatigue, intolerance to cold, headaches and irritability, increased tiredness when exercising, hair loss and decreased immunity.

Should you experience any of these symptoms, follow up with your doctor. A thorough checkup can detect not just iron deficiency, but other conditions that have similar symptoms. 

What do I do if I am iron deficient?

First, work with your doctor to determine the underlying cause of iron deficiency, and secondly, contact a dietitian who can help boost iron levels in your diet though diet and if needed, supplementation.

Iron deficiency is detected by checking the serum ferritin levels.  Ferritin is a protein that stores iron in the body, which means it reflects the tissue stores of iron, and it is not impacted by recent iron intake (if you had a steak before the blood test next day your ferritin levels will be unaffected.)

Ferritin can be elevated during infections as well, or with increased inflammation, obesity or trauma meaning sometimes ferritin levels may not directly reflect iron status. Your healthcare professional will be able to look at your iron and ferritin levels and determine whether you are iron deficient.

Foods rich in iron

There are two types of iron, heme and non-heme.  

Your body absorbs heme iron more easily than non-heme. Iron-rich plant foods contain only the non-heme iron, but they are still important sources of iron in your diet.

The list below is by no means conclusive, but it can get you started in learning more about which foods contain iron, both heme and non-heme.

Heme iron sources:

Non-Heme iron sources:

mL = millilitres, g = gram, oz. = ounce, mg = milligrams

Above values were adapted from Canadian nutrient file and Healthlink BC

Other factors to consider about iron content in foods and factors that affect iron absorption:

• The amount of iron in enriched or prepared foods, such as pasta or prune puree can vary by product. Always read the nutrition facts table to find out specific amounts in the foods you are choosing.
• Liver and liver products (such as liver sausages or liver spreads) can contain high amounts of vitamin A, which may increase risk of birth defects, especially during the first trimester of pregnancy. Health Canada suggested avoiding liver products while pregnant.
• Some nutrients, such as calcium or zinc, can compete with iron for absorption. Other substances that may decrease iron absorption include polyphenols found in found in black tea and coffee, so try to avoid drinking coffee or black tea with meals. I suggest having your coffee or tea at least 30 minutes before or after your meal.
• Vitamin C, a powerful antioxidant, can increase the absorption of non-heme iron. It’s always a good idea to eat foods that contain vitamin C (think bell peppers, strawberries, oranges, lemons, parsley) with your iron-rich foods.

What about supplements?

Ingesting too much iron, which can happen when taking iron supplements, can lead to unhealthy high levels. To avoid that, you can talk to your doctor and dietitian prior to taking iron supplementation. Supplementation is an individualized approach and is not considered safe for everyone. However, you can learn all about it by booking an appointment with me today and we can get you started!