Curious About Iron?

What it is?

Did you know Iron is one of the most common nutrient deficiencies around the world? What makes this vitamin so important and why is deficiency so common?

Iron is a mineral that is found naturally in some foods and is fortified in products including grains. Iron is found in two forms (heme and non heme iron) depending on the food source. Many animal/meat sources contain heme iron, while plant and dairy food sources contain non-heme iron.  The bioavailability of iron is around 14-18% and this decreases to 5-12% from plant/dairy sources of food. But do not worry even non-meat eaters can consume adequate amounts of iron in their diet!

Why we need it?

Iron in our body is found mainly as hemoglobin, which is a protein that transports oxygen to our tissues. The amount of iron stored is directly related to our serum ferritin levels. This makes iron necessary for physical growth, neurological development, cellular function and synthesis of some hormones. With iron deficiency, this can affect both physical endurance as well as cognitive performance and can cause fatigue. Many of us can consume adequate amounts of iron in our diet however those at risk for developing iron deficiency includes: young women, adolescent athletes, those who limit/avoid meat products, pregnancy (as pregnancy progresses, women need more iron), older adults, conditions that may impact absorption (IBD, celiac, bariatric surgery), and toddlers/infants. And yes this is a long list! So lets talk about what we can do to minimize our risk!!

  1. Watch for Symptoms of low iron and advise your doctor if you think you may be deficient in iron
    – Fatigue, headaches, irritability/depression, cold intolerance, hair loss, impaired immune function, decreased performance, PICA
  2. Include iron rich foods at meals/snacks (ideas listed below)
  3. Include a wide variety of different foods in your diet (Pro tip: Having heme iron sources can enhance non heme iron absorption as well)

So how much should I be eating?

The amount of iron required depends on an individual’s age, sex, and stage of life.

Infants (0-6 months): 0.27 mg/d
Infants (6 months+): 11 mg/d
Children (1-3 years): 7 mg/d
Children (4-8 years) 10 mg/d
Adolescents: Girls 8-15 mg/d – Boys 8-11 mg/d
Adult Men: 8 mg/d
Adult Women: 18 mg/d
During Pregnancy: 27 mg/d

Around 6 months of age, a baby’s iron needs will increase as the stores that we are born with start to deplete. During this stage focus on iron rich foods as baby’s first foods.

For those who avoid meat products or have limited meat intake, iron requirements may be up to 2x as high due to the lower bioavailability of non heme iron in plant and dairy sources.

Dietitian Tips:

Having a source of Vitamin C (ascorbic acid) will help increase absorption of iron! Aim for 125 ml orange juice or 250-500 mg ascorbic acid source.

Calcium rich foods will have the opposite effect! Avoid taking iron supplementation with calcium rich foods or supplements as calcium can inhibit iron absorption by as much as 60%. Other foods that may decrease absorption of iron include phytates and polyphenols which are present in grains and beans as well as tannins/oxalates that are found in tea/coffee.

For supplementation, ferrous sulfate tends to be well tolerated. If you struggle with GI upset/constipation with iron supplementation you can try: taking it every other day, switching to formulation with lower elemental iron, try switching to liquid form

Should you supplement everyday?

Aim to choose iron rich foods, if diet is limited in meat/animal products consider iron supplementation or choose a multivitamin with iron and if suspected deficiency, you can talk with doctor about testing iron levels.

Iron Rich Foods

Heme Iron Sources:
– Oysters 8 mg/3 oz
– Beef Liver 2.4 mg/75gr
– Sardines 2mg/3oz
– Beef 2.5 mg/3oz
– Chicken/Turkey 1mg/3oz

Non Heme Iron Sources:
– Fortified Breakfast cereals 7mg/28gr
– Dried Soy Beans 6.5 mg/175ml
– Lentils 5 mg/175ml
– Tofu (firm) 2.5mg/150gr
– Spinach 3.5mg/half cup

*See attached for full list of iron rich foods

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