How important is magnesium during pregnancy?

The mineral magnesium performs many important tasks in our body. Apart from its stabilizing function in our bone formation, it regulates the energy metabolism in our cells and is involved in the activation of over 600 enzymes, as has recently become known. A well-adjusted magnesium balance makes us more stress-resistant and even-tempered, as it regulates the cardiovascular system and ensures healthy blood pressure. Last but not least, magnesium is important for controlling muscle contractions and especially for subsequent relaxation. Otherwise, owing to its relaxing function, magnesium is important for women when they are not pregnant because a balanced magnesium level contributes to loosen cramps and alleviate menstrual pain, among other things.


What effect of magnesium in our muscles?

In order that they function normally, our muscles need a balanced ratio of magnesium and calcium. The latter is necessary for muscle tension, whereas the former is needed for relaxation. If the calcium concentration in the muscle increases due to magnesium deficiency, the muscle can no longer relax and cramps occur. Magnesium achieves its cramp-loosening effect by making cell membranes "impermeable", so the electrolyte balance is restored back to normal (i.e. the concentrations inside and outside of the cell are balanced again). Calcium and other electrolytes like potassium and sodium are hindered from continuing to penetrate into muscles and nerve cells. This lowers nerve cell excitability and muscle cramps are less likely.

How does a magnesium deficiency affect pregnancy?

Many pregnant women complain about calf cramps and vague abdominal pain that can occur as a consequence of magnesium deficiency. Other magnesium deficiency symptoms are strong palpitations and exhaustion. All of them are not, as such, a reason to start worrying yet, but you should nonetheless listen to your body's signals and possibly undergo a test for magnesium deficiency. If strong magnesium deficiency occurs during pregnancy, a contracted womb cannot relax any longer. Consequently, there are cramps that could trigger premature contractions – and lead to premature delivery in serious cases. When there is magnesium deficiency the balancing effect on the cardiovascular system ceases and the risk for pregnancy hypertension rises. In addition, magnesium deficiency is also suspected to be responsible for the onset of preeclampsia and the intensification of pregnancy nausea.

Immediate symptom relief occurs as soon as the magnesium deficiency is offset and no permanent damage remains. Thus, a balanced magnesium level is essential for the well-being of mother and child.

How much magnesium should you take during pregnancy and breastfeeding?

For pregnant women, the German Nutrition Society recommends a daily magnesium intake of 310 mg (i.e. slightly above the recommended amount for non-pregnant women over 25 years of age). One of the reasons is that owing to hormonal changes during pregnancy, more magnesium is excreted through the urine. In addition, magnesium plays a role in the embryo's cell division and growth. In the late stages of pregnancy, the unborn child must be supplied with magnesium. In the last three months of pregnancy, the embryo stores up to 7 mg of magnesium in the growing bones and muscles.

Breastfeeding women have once again a higher need of 390 mg because they pass on a lot of magnesium to their child through the breast milk, which contains on average 3 mg of magnesium for each 100 ml. The newborn urgently needs it for his biofactor supply.

How long do you need to supplement magnesium during pregnancy?

In order not to risk a magnesium deficiency, you can already bring your magnesium balance up to the recommended level when you are thinking of conceiving. Many physicians recommend maintaining it throughout pregnancy and until the end of breastfeeding. In this way, the magnesium level of mother and child remains balanced for sure during the important first months.

Which foods contain magnesium?

Nuts and seeds have the highest amount of magnesium – the leaders being sunflower seeds and linseed, with 420 and 350 mg of magnesium for each 100 g. However, wheat germ and oats also have respectable quantities of magnesium. One portion of a colorful muesli a day – maybe with two added banana slices (45 mg of magnesium for each 100 g of bananas) – already takes care of most of the daily magnesium dose, especially when one or two glasses of magnesium-rich mineral water are taken. Nonetheless, every third women does not reach the recommended values because our body cannot utilize magnesium from plant-based foods. The reason is that the phytates commonly found in plant-based foods bind the magnesium taken with the diet and we directly excrete most of it.

Side effects of magnesium during pregnancy

Healthy individuals excrete the excess of magnesium in the blood through the kidneys and into the urine. If you take a lot of magnesium all at once, one part of the dose moves through the intestine untouched and is once again excreted with the stool – because less is absorbed as the intake increases. This can even lead to a side effect, namely that magnesium's slightly laxative effect mitigates the constipation that often occurs during pregnancy.

Taking small doses of magnesium throughout the day can easily prevent this side effect. For example, effervescent granulate can be dissolved in 500 to 750 ml of water and taken over the course of the day. Alternatively, and in consultation with your physician, suitable medicines or food supplements containing not too high doses can also be taken throughout the day.

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