Pumping iron isn’t just for the gym. You can — and should — pump it up in your pregnancy diet, too. Iron is essential during pregnancy to support your baby's development, as well as your own wellbeing.
The mineral is so vital for baby's growth, in fact, that your recommended daily intake nearly doubles when you're expecting. Having low iron stores can increase your risk of developing anaemia, and severe iron deficiency may lead to low birthweight or premature birth.
With that in mind, is it necessary to take iron supplements when you're pregnant? Here's everything mums-to-be need to know about iron during pregnancy, including how to fill up on iron-rich food sources and how to know if supplementary iron is something you need.
Why is iron important during pregnancy?
Menstrual cycle is one of the biggest causes for low iron and ferritin depletion. So, it may seem counterintuitive that you would need more iron during pregnancy as you aren’t bleeding! Well, in pregnancy, iron acts as a life-starter. Delivering oxygen to your growing baby is one of it’s most important jobs, and frankly, you now have more blood in your body. Almost double the amount compared to your pre-pregnancy self, actually. Hence, the need for higher iron and ferritin levels. For baby, iron is also an important brain development factor, meaning that low haemoglobin and ferritin may disrupt baby’s brain development and cause a preterm birth. Scary stuff, so it’s important to keep on top of things!
Let’s not forget: pregnancy is hard as it is. Adding to that the most common symptoms of iron deficiency – feeling lousy, fatigued, weak, short of breath, looking pale, having palpitations, and dizziness when you stand up – it can get fairly unbearable.
Your iron intake is most important in the third trimester as this is when your baby begins to build their own iron stores ready for the first months of life. These stores are used until your baby starts on solids.
Instead of going to the nitty gritty of exactly how much iron you need per day, it’s better to just think: ‘I’m pregnant, so I need to roughly double my iron intake.’ And you can do a lot with foods!
Learn more: Ferritin and iron deficiency in a nutshell.
Best iron-rich foods for pregnant women
There are two types of iron in food: Iron from animal foods (called haem iron) and iron from plantbased foods (called non-haem iron).
Haem iron is taken up by the body about ten times better than non-haem iron. Meats are the best source of it. The redder the meat, the higher it is in iron. This means beef and lamb are higher in iron than pork, chicken or fish. Coloured flesh fish, such as tuna and mullet, are higher in iron than white fish, such as cod.
Non-haem iron is found in some plant foods such as:
- Wholegrain and iron-fortified breads and cereal foods (these are foods with added iron)
- Legumes (e.g. kidney beans, baked beans, chickpeas, lentils)
- Fermented soy products (e.g. tofu)
- Green leafy vegetables (e.g. spinach, broccoli, bok choy)
- Nuts and dried fruit
Remember that non-haem iron foods are not taken up by the body as well as iron from animal foods. You may need to eat more of these foods if they are your only iron source, for example if you follow a vegan or vegetarian diet.
Interestingly, what you consume with your iron can affect how well your body absorbs the mineral. Whether you take iron supplements or eat iron-rich foods, downing them with high-calcium foods such as milk or cheese will reduce the intended benefit. If you want to have a bowl of cereal with milk in the mornings, don’t take your supplement at the same time. On the other hand, taking iron with some type of acid like a glass of orange juice or tomato on your burger can boost its absorption. Enjoying heam iron (animal based iron) at the same time with your supplements can also help your body to optimise the iron absorption – and vice versa! If you are eating lots of plant-based foods, it’s a good idea to add to your chances by getting some vitamin C during the meal. Maybe you’d like an orange for dessert?
Should you take iron supplements during pregnancy?
Iron tablets or liquid (supplements) should only be taken when a blood test has confirmed that your levels are low. It is best that you discuss what type of iron tablet is best for you with your doctor, midwife, or dietitian. Many pregnancy vitamins contain some amount of iron, but this is usually in an extremely low dosage. A middle-range pregnancy vitamin may contain the following:
- Vitamin D
- Vitamin E
- Vitamin B (B1, B2, B3, B5, B6, B12)
- Folic acid
- Vitamin C
Vitamin A is not included, as that has been linked to adverse effects to your and baby’s wellbeing during pregnancy. Folic acid and vitamin C are important on their own, but they also promote iron absorption.
Now, more about iron. You may experience constipation (difficulty opening your bowels) as a side effect from taking iron supplements. Some formulations are easier on your tummy, for example generally the liquid forms are little better tolerated by those with sensitive stomachs. However, there are several ways to manage constipation:
- Eating more unprocessed plant foods like fruits with the skin on, vegetables, wholegrains, legumes. Plums are excellent, and you can even soak your dried plums in some water, and then eat the plums and drink the liquid.
- Drinking more water.
- Being physically active.
- Taking your iron tablet every second day (discuss with doctor).
- Talking to your doctor or midwife about using a different type of iron supplement (i.e. liquid iron).
Tea, coffee, bran and some medications can block plant iron (non-haem iron) being taken up by the body. Drinks rich in calcium such as milk block the absorption of iron in the gut. Limit iron blockers when you are eating foods rich in iron to optimise your iron intake.
The bottom line
For most women, iron supplementation is safe during pregnancy. However, not every mum-to-be needs extra iron, especially since the mineral is already in most prenatal vitamins and can be found in certain foods. As always, talk to your practitioner before adding any new supplements to your diet.