Magnesium in pregnancy: what you should know

Magnesium, an essential mineral for the human body, plays a particularly important role during pregnancy. It not only supports vital bodily functions of the mother, but is also crucial for the healthy development of the unborn child. A magnesium deficiency during this sensitive phase can lead to complications that pose serious health risks for both mother and child. The following questions often arise in this context: How can a magnesium deficiency be identified and effectively treated? And what measures should expectant mothers take to ensure optimal magnesium levels during pregnancy?

Table of Contents

• What is magnesium?
• What are the functions of magnesium?
• What role does magnesium play during pregnancy?
• How much magnesium is needed during pregnancy?
• What are the symptoms of magnesium deficiency during pregnancy?
• What causes magnesium deficiency in pregnancy?
• How can I meet my magnesium needs?
• Are magnesium supplements safe during pregnancy?
• Summary

What is magnesium?

Magnesium is an essential mineral that forms a key component of many tissues and organs in the human body. The majority of magnesium—around 60%—is stored in the bones, where it plays a structural role and contributes to bone strength and density. Another 39% is located in muscles and soft tissues, highlighting its importance for muscle contraction and relaxation. The remaining magnesium is dissolved in body fluids, where it plays a crucial role in nerve signal transmission, muscle contraction, and maintaining a regular heart rhythm (NIH, 2023).

The occurrence of magnesium deficiency during pregnancy varies depending on the study and population examined. However, it can be said that magnesium deficiency among women of childbearing age is common in both developing and industrialized countries, and most pregnant women likely do not meet the increased magnesium requirements during pregnancy (Dalton et al.,2016).

What are the functions of magnesium?

Magnesium is an essential mineral that fulfills a number of vital functions in the human body:

• Enzyme activation: It activates over 300 enzyme systems responsible for numerous biochemical reactions, such as energy metabolism and the synthesis of proteins and DNA.
• Muscle and nerve function: Magnesium is critical for the smooth functioning of muscles and nerves, as it helps with nerve impulse transmission and regulates muscle contraction (Fiorentini et al., 2021).
• Heart health: Magnesium contributes to maintaining a regular heartbeat and is involved in regulating blood pressure. Studies increasingly show that adequate magnesium intake is associated with a lower risk of cardiovascular diseases (Fiorentini et al., 2021).
• Bone health: Magnesium supports the structure of bones and teeth and is important for calcium absorption and metabolism.
• Electrolyte balance: It is essential for maintaining electrolyte balance in the body, which is necessary for hydration, nerve function, and muscle contraction.

Source: MedlinePlus, 2021

What role does magnesium play during pregnancy?

During pregnancy, the functions of magnesium become even more significant due to the physiological changes and increased demands during this period. The need for magnesium rises during pregnancy. It helps prevent uterine contractions, reduces the risk of preterm labor, and supports the development of the baby’s skeletal system (Fanni et al., 2021).

Important to know: Preeclampsia is a serious condition that can occur during pregnancy, marked by a sudden rise in blood pressure and often increased protein levels in the urine. It usually occurs after the 20th week of pregnancy and can become dangerous for both mother and child if left untreated. Early detection and treatment are essential to protect the health of both (NHS, 2021). There is currently limited research on how magnesium affects the risk of severe preeclampsia. In a normal pregnancy, magnesium appears to have little influence on the risk of preeclampsia, but it may help reduce the risk in women who are already at high risk of developing it (Yuan et al., 2022).

How much magnesium is needed during pregnancy?

The daily magnesium requirement varies depending on individual factors such as age, gender, pregnancy, physical activity, diet, health status, and medication use. While pregnant women require approximately 350–400 mg per day, non-pregnant women need about 310–320 mg. These values can vary individually (NIH, 2023). 

What are the symptoms of magnesium deficiency during pregnancy?

The first warning signs of magnesium deficiency during pregnancy can vary but typically include muscle cramps—especially in the legs—and a general feeling of fatigue or weakness. These symptoms should not be ignored, as they may indicate a deficiency that requires further investigation. Common symptoms include:

• Cramps and muscle pain

• Persistent fatigue and weakness

• Nausea and loss of appetite

• Heart rhythm disturbances

• Mood swings and irritability

Source: Zarean &Tarjan, 2014

Do these symptoms sound familiar to you? And are you perhaps pregnant?

A magnesium deficiency could be the cause. With the Magnesium Test from Homed-IQ, you can quickly and conveniently gain clarity about your symptoms—without the time commitment of scheduling a doctor’s appointment. This test allows you to check your magnesium level from home and take appropriate steps to improve your health if necessary.

What causes magnesium deficiency in pregnancy?

During pregnancy, magnesium deficiency can occur for a variety of reasons. Some of the most common causes include:

• Increased demand: Magnesium needs rise during pregnancy because it is essential for the healthy development of the fetus. Magnesium absorption is also influenced by calcium and vitamin D intake, as well as vitamin D status.
• Inadequate diet: An unbalanced diet that lacks sufficient magnesium-rich foods such as whole grains, nuts, seeds, and leafy green vegetables can lead to a deficiency.
• Morning sickness and vomiting: Common symptoms like nausea and vomiting—especially in the first trimester—can interfere with magnesium absorption and retention.
• Digestive problems: Gastrointestinal issues, such as diarrhea, can impair the body's ability to absorb magnesium efficiently.
• Health conditions: Pregnant women with preexisting conditions such as kidney disease, high blood pressure, diabetes, or thyroid disorders may be at higher risk for magnesium deficiency. Regular monitoring is recommended in these cases.

Source: Dalton et al.,2016

How can I meet my magnesium needs?

Magnesium is found in a wide variety of foods. The image shows which foods are particularly rich in magnesium.

Source: NIH, 2022; Cleveland Clinic, 2020

Are magnesium supplements safe during pregnancy?

A balanced diet rich in a variety of foods is essential for providing the body with necessary nutrients. Since foods contain both nutrients and other health-promoting compounds, it is best to meet nutritional needs through dietary intake (NIH, 2023). However, there may be situations in which it is difficult to obtain all nutrients through diet alone. In such cases, fortified foods or dietary supplements can be useful to address specific deficiencies.

Pregnant women are in an especially sensitive phase in which both nutrient excess and deficiency can pose risks to both mother and baby. For this reason, supplements should never be taken without prior consultation with a doctor.

Although some studies highlight the potential benefits of magnesium supplementation during pregnancy, there is not yet sufficient high-quality evidence to confirm that magnesium supplements are clearly beneficial during pregnancy (Makrides et al., 2014;NIH, 2023 )

Summary

Magnesium plays a vital role in pregnancy by supporting the health of the mother and the development of the fetus. A balanced magnesium level can be achieved through a magnesium-rich diet and, if needed, supplementation. It is important to pay attention to the body’s signals and seek medical advice if a deficiency is suspected.