Magnesium in pregnancy and for children: safe or not?
Is magnesium safe during pregnancy?
Magnesium from food is not just safe but essential. The need increases slightly during pregnancy, and the mineral contributes to normal muscle function and to a reduction of tiredness. Many pregnant women get enough through a varied diet. Supplements may be worth considering for problems like leg cramps, but choose the dose in consultation with your midwife.
Avoid high doses on your own. During pregnancy the precautionary principle applies – stick to food and to supplements within the reference intake unless your healthcare provider advises otherwise.
Can magnesium help with cramps during pregnancy?
Leg cramps are common, especially at night in the third trimester. Some studies show fewer cramps with magnesium supplements, others no clear effect. Since the risk is low, many midwives suggest trying it. Read more in our review of magnesium for cramps.
Magnesium contributes to normal muscle function – agree the dose with your midwife.
See current price »How much magnesium do pregnant women need?
The reference intake for adults is around 300–375 mg per day, and the need only increases marginally during pregnancy. For most people, food goes a long way. Rich sources include nuts, seeds, whole grains and leafy greens – see our list of magnesium-rich foods.
| Group | Approximate need/day | Comment |
|---|---|---|
| Pregnant adult | ~300–375 mg | Food is often enough |
| Children 1–3 years | ~80 mg | Through food, not supplements without advice |
| Children 4–10 years | ~120–200 mg | Through food |
Can children take magnesium?
Children need magnesium for normal development, but the need is almost always covered by food. Do not give adult doses to children. If you want to give a supplement – for example for a confirmed deficiency – only do so on the advice of a paediatrician or child health clinic, who will adjust the dose for age and weight.
Which form and when?
During pregnancy many choose a mild, well-absorbed form such as glycinate, which is gentle on the stomach. Magnesium oxide can have a laxative effect, which can be either helpful or bothersome depending on your stomach. The differences are covered in our guide to magnesium forms. If you take it for night cramps, the evening works well – more in our guide on when to take magnesium.
Products can be found in the daily support collection, and there's a comparison on our best magnesium page.
When should you ask a healthcare professional?
Always check supplements during pregnancy and breastfeeding with your midwife or doctor, especially if you take other medication or have kidney problems. The same applies for children, via a child health clinic or paediatrician. Ask a pharmacist if you are unsure about a product.
Can you take magnesium while breastfeeding?
Yes, magnesium from food and from supplements within the reference intake is considered compatible with breastfeeding. The need is roughly the same as for other adults, and a varied diet often covers it. Just as during pregnancy, be cautious with high-dose products – stick to sensible amounts and check with your midwife or doctor if you take other medication or are unsure. If you get stomach discomfort, a milder form such as glycinate may be gentler than oxide.
Magnesium-rich foods for the whole family
The simplest and safest way to get magnesium – for both pregnant women and children – is through food. Build your meals around foods that naturally contain the mineral:
- Whole grains such as oats, rye bread and wholegrain pasta
- Legumes such as lentils, chickpeas and beans
- Nuts and seeds, for example almonds, pumpkin seeds and sunflower seeds
- Leafy greens such as spinach
- A piece of dark chocolate as a snack
The full list with amounts is in our article on magnesium-rich foods. For young children this is the way to go – not adult supplements.
Common questions and misconceptions
A common misconception is that more magnesium is always better during pregnancy. It isn't. The need only increases marginally, and large doses are more likely to cause loose stools than any extra benefit. Another misconception is that children need the same supplements as adults – children's needs are lower and are almost always covered by food. If your child is a picky or one-sided eater, raise it with your child health clinic before considering supplements, so the dose is right for their age and weight.
What is magnesium good for during this time?
Magnesium contributes to normal muscle function, to a reduction of tiredness and fatigue and to normal functioning of the nervous system – all things that are easily put to the test during pregnancy and with small children in the house. It doesn't replace sleep and recovery, of course, but making sure your magnesium stores are topped up through food is a simple foundation. If you want to read more about the mineral's roles, see our overview of what magnesium is good for.
Symptoms to keep an eye on during pregnancy
Some pregnancy complaints can resemble signs of low magnesium intake, but they often have entirely different explanations. Leg cramps, tiredness and restless legs are common precisely because your body is changing, not necessarily because you are deficient. That's why it's important not to self-diagnose and start on high doses. Instead, talk to your midwife, who knows your overall situation and can judge whether a supplement is reasonable and, if so, at what dose. The same applies if you feel unusually tired or get heart palpitations – these things should always be raised with a healthcare professional rather than assumed to be a mineral deficiency. The basic rule during pregnancy and breastfeeding is simple: treat food as your primary source, stick to sensible amounts if you supplement, and let your healthcare provider guide you at the slightest uncertainty. That way you get the benefits of magnesium – which contributes to normal muscle function and to a reduction of tiredness – without taking unnecessary risks. Products can be found in the daily support collection and a comparison on our best magnesium page, but always check with your midwife first.
What about magnesium after giving birth?
After giving birth, the need for magnesium is roughly the same as for other adults, and a varied diet covers it for most people. New parents often sleep badly and eat irregularly, which can drain the body's stores of several nutrients at once. Prioritising simple, magnesium-rich meals – porridge, nuts, legumes and green vegetables – is an easy way to keep levels up without having to think about supplements. If you are breastfeeding, the same caution applies as during pregnancy: stick to sensible amounts if you supplement, and check with your midwife or doctor if you are unsure or take other medication. If you feel unusually tired, low or get heart palpitations, raise it with a healthcare professional rather than assuming it's a mineral deficiency – there are other possible causes that are important to rule out.
Frequently asked questions
Is it safe to take magnesium during pregnancy?
Magnesium from food is safe and needed during pregnancy. Supplements within the reference intake are also considered safe and are sometimes used for leg cramps. Avoid high-dose products on your own and choose the dose in consultation with your midwife, especially if you take other medication or have kidney problems.
Does magnesium help with leg cramps when pregnant?
It may help. Leg cramps are common in the third trimester, and some studies show fewer cramps with magnesium while others don't. Since the risk is low, many midwives suggest trying it. Magnesium contributes to normal muscle function, but talk to your midwife about the dose before starting.
Can children take magnesium supplements?
Children need magnesium, but the need is almost always covered by ordinary food. Never give adult doses to children. If a supplement is being considered, for example for a confirmed deficiency, the dose should be adjusted for age and weight by a paediatrician or child health clinic. Always start with diet for the youngest.
How much magnesium does a pregnant woman need per day?
The need is around 300 to 375 mg per day and only increases marginally during pregnancy. For most people, a varied diet with nuts, seeds, whole grains and leafy greens is enough. If you need to supplement, stay around the reference intake and check with your midwife before starting.