Iron Needs During Pregnancy and Beyond

Iron is essential during all stages of life and intake requirements increase during pregnancy. It is found in many types of foods but absorption rates are highly varied. High and low intake of iron can be problematic, so levels should be tested prior to adding a supplement.

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What is iron and why do I need it?

Iron is an essential mineral that supports proper metabolism, cellular growth, function, and development. It is a key component of hemoglobin, which is a protein in red blood cells responsible for delivering oxygen from the lungs to muscles and other tissues in the body. Iron is naturally present in many foods, commonly fortified in others, and readily available in supplement form.

During pregnancy, iron supports the growth of the placenta and is essential for the baby’s developing brain. As your blood volume increases by 50% in the second and third trimester, so do your iron needs. In the US, 18% of pregnant women have an iron deficiency, and those rates are even higher in the third trimester with nearly 30% of women being deficient [1]. Deficiencies in iron are associated with anemia in mom and baby, preterm birth, and low birth weight, however, high levels of iron can be harmful as well [2,3].

How much iron do I need?

The recommended dietary allowance (RDA) of iron from the National Academy of Medicine (NAM) is [4]:

• All women over the age of 19: 18 mg
• During pregnancy for all ages: 27 mg
• During lactation for women over the age of 19: 9 mg

NAM includes an important note that due to a lower bioavailability of iron in vegan and vegetarian foods, the recommended intakes are 1.8 times higher [4]. That makes the following adjusted RDAs for vegans:

• Vegan women over the age of 19: 32.4 mg
• Vegan pregnancy for all ages: 48.6 mg
• During lactation for vegan women over the age of 19: 16.2 mg

The recommended iron intake for lactating women is the same as the recommended intake for men. This is because the majority of our iron loss comes from menstruation. However, I am surprised at the assumption women don’t get their periods while breastfeeding since many, in fact, do. Once your period has restarted after giving birth, regardless of whether or not you’re still breastfeeding, your iron needs increase.

The upper intake level (UL) for everyone over the age of 14 is 45 mg per day [4]. High levels of iron can block the absorption of other essential minerals. Also, excess intake is associated with gastrointestinal distress, vomiting, and can be toxic.

Interestingly, the toxicity potential from too much iron is only present with animal sources of iron, not plant sources. This is because our bodies are able to regulate the absorption of nonheme iron and flush out excess amounts, which is not the case for heme iron [5]. Our body’s harmonious balance with plants never ceases to amaze me!

Can I get enough iron from food?

Plant-based diets are found to be higher in iron content than any other diets that contain animal products [6]. However, vegans need to be aware that the absorption of iron from plant-based foods is lower than from animals. That is not to say that sufficient levels cannot be achieved from food alone.

The following food groups have some of the highest iron levels:

• Legumes: soybeans, lentils, chickpeas
• Leafy greens: spinach, chard, kale
• Seeds: hemp seeds, pumpkin seeds, flax seeds
• Tomato-derived foods: sun-dried tomatoes and tomato paste
• Grains: oats, spelt, buckwheat
• Potatoes with skin

Naturally occurring iron comes in two forms: heme and nonheme iron. Plants have only nonheme iron while animals have both types. Fortified foods generally have the nonheme form. The absorption of nonheme iron is strongly influenced by its solubility and interaction with other nutrients [7].

To increase bioavailability, consume iron-rich foods with ones that are high in vitamin C, such as oranges, strawberries, bell peppers, tomatoes, and broccoli. Soaking, fermenting, and germinating foods such as beans and grains increases the bioavailability of iron as well.

What’s a perfect iron-rich, vitamin-C-containing, protein-packed, fiber-filled, easy-to-make vegan meal? Rolled oats made with soymilk, hemp seeds, and raspberries! This simple meal provides nearly 8 mg of iron, 42% of your daily vitamin C, 27 g of protein, and 85% of your daily fiber needs. Sounds like the perfect way to start your day.

Which one is best: heme or nonheme iron?

At first glance, the heme iron from animals appears superior since it is more bioavailable (15-35% as compared to 1-34% bioavailability of the non-heme form) [7]. However, the absorption of iron from plant foods can be the same as from animal foods, when combined with vitamin C or soaked prior to cooking.

Also, concerns have been raised by researchers in the connection between heme iron and strokes, type 2 diabetes, and certain types of cancers. You can read further about this from Dr. Michael Greger’s analysis on NutritionFacts.org.

So while heme iron from animals is more bioavailable, the intake of nonheme iron from plans is safer.

Do I need to supplement with iron?

It is likely that you need to supplement with iron during pregnancy, given the increased RDAs for vegans.

Even though plant-based diets provide a rich source of iron, research findings still indicate that vegans tend to have lower serum levels [8]. This isn’t much different from the general population since iron deficiency is more common than any other nutrient deficiency worldwide [4]. For this reason, it is wise to have your iron levels checked every few years and only add a supplement if it’s deemed necessary.

If you’re pregnant and have an iron deficiency, follow your healthcare provider’s recommendations for getting those levels up. It is likely that a supplement will be recommended and your blood levels will continue to be monitored.

Of course, if your iron stores are within a healthy range, there’s absolutely no need or benefit to adding a supplement.

How to select a vegan iron supplement?

The plant-derived nonheme form of iron is most common in supplements. You’re generally safe unless a supplement specifically states that it contains a heme form (also referred to as iron polypeptides or iron amino-acid chelates).

You’ll often see claims that a particular supplement is “gentle on the stomach”, but you may need to try a few different ones to find a brand that really works well for you. Also, note that your multivitamin or prenatal supplement may have iron included.

There are many vegan iron supplement options available, so I will simply list my favorite one: Floradix Iron & Herbs. It is in liquid form so it’s easy to measure and change how much I’m taking. Years ago when I had a deficiency (prior to becoming vegan) I tried different tablets and my iron levels didn’t increase substantially until I switched to Floradix. This is the supplement I took during my pregnancy as well, in addition to a prenatal supplement that contained iron.

Summary

1. It’s likely that vegans need to supplement with iron during pregnancy, but getting levels checked first is recommended
2. Increase the bioavailability of iron in plant foods by soaking them or consuming them with foods that are high in vitamin C.
3. If supplementing, choose a nonheme (plant-derived) form of iron.