Low Iron in Pregnancy: What to Actually Do About It

If your provider mentioned low iron at your last appointment, you're in very good company — iron deficiency is one of the most common things I help clients navigate during pregnancy. But I also want to clear up something that trips a lot of people up: the number that matters isn't always the one you think.

It's not just about hemoglobin

Most people assume that if their hemoglobin looks fine, their iron is fine. But especially by the second trimester, I like to look at ferritin too — that's your body's iron storage level, not just what's circulating in your blood right now. Ferritin can start dropping well before hemoglobin does, since your body pulls from those reserves first. So if you're feeling wiped out, foggy, or unusually short of breath but your hemoglobin came back "normal," it's worth asking your provider specifically about checking ferritin.

It's a small ask that can catch a deficiency early, before it progresses.

Getting more from the iron you eat

The good news: how you eat iron-rich foods can matter just as much as how much you eat. A few things I coach clients on constantly:

Pair iron with vitamin C. Iron from plant sources (beans, spinach, fortified cereals) is absorbed much better when eaten alongside something vitamin-C rich. Think: spinach salad with orange slices, lentils with a squeeze of lemon, or bell peppers alongside a bean bowl. This one swap can meaningfully boost how much iron your body actually takes in.

Give calcium some space. Calcium and iron compete for absorption, so if you're taking a calcium supplement or having a big glass of milk, try not to have it at the exact same time as your iron-rich meal or prenatal vitamin. An hour or two of separation is usually enough.

Keep coffee and tea at a distance too. Both contain compounds that can block iron absorption, so it's worth having your coffee or tea an hour before or after iron-rich meals, rather than alongside them.

The bigger picture

None of this needs to feel like a rulebook you're failing to follow perfectly. Start with one small shift — maybe just adding a vitamin-C food alongside your iron-rich meals this week — and build from there. Your food story doesn't need to be perfect to be effective.

If you've been told your iron or ferritin is low and you're not sure where to start, I'd love to help you build a plan that actually fits your week.

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Amanda Reed, MS, RD, is a Registered Dietitian Nutritionist in NYC specializing in nutrition before, during, and after pregnancy.