Magnesium is a mineral involved in over 300 biochemical reactions throughout the body. During pregnancy, physiological demands increase significantly, raising the need for this nutrient to support maternal health and fetal development. Supplementation is often sought to ensure adequate intake during this period of high demand. Choosing the right form of magnesium is important because different compounds are absorbed and utilized in very different ways.
Essential Functions of Magnesium During Pregnancy
The mineral plays a fundamental role in regulating muscle function, which becomes particularly relevant as the body adapts to pregnancy. Magnesium helps to control the contraction and relaxation of muscles, and a deficiency is frequently associated with nocturnal leg cramps. Supplementation can help to alleviate this painful and disruptive symptom.
Magnesium is also deeply involved in the creation of new tissue, which is directly tied to fetal growth and development. It is required for the synthesis of DNA and RNA, and is a component of healthy bone structure for both the mother and the developing baby. Furthermore, it supports cardiovascular health by helping to maintain normal blood pressure levels. Adequate intake has been associated with a potential reduction in the risk of complications such as preeclampsia. The mineral also assists in maintaining healthy blood sugar levels by supporting insulin sensitivity, important given the risk of gestational diabetes.
Understanding Magnesium Supplement Forms
The effectiveness of any magnesium supplement depends heavily on its bioavailability, which is the degree to which the body can absorb and use the mineral. Magnesium is sold in various forms, each compounded with a different salt or substance that affects its solubility and absorption rate. Forms that dissolve easily in water generally have higher bioavailability and are absorbed more completely in the digestive tract.
Some common forms, such as Magnesium Oxide, are poorly absorbed by the body, meaning a large percentage passes through the digestive system unused. Due to this low absorption, Magnesium Oxide often draws water into the intestines, making it primarily useful as a laxative or antacid. Other highly soluble forms, like Magnesium Citrate, are better absorbed but can also produce a significant laxative effect when taken in higher doses. Chelated forms, where the magnesium is bound to an amino acid like glycine, are engineered for improved absorption and better digestive tolerance.
Selecting the Optimal Magnesium for Prenatal Use
For daily prenatal supplementation, the primary goal is to increase magnesium stores without causing gastrointestinal distress. Magnesium Glycinate, or its counterpart Magnesium Bisglycinate, is generally considered the optimal choice. This is a chelated form where the magnesium is bound to the amino acid glycine, resulting in a highly bioavailable compound.
The chelation process allows the mineral to pass through the digestive tract gently, significantly reducing the likelihood of diarrhea, bloating, and cramping associated with other forms. This gentleness is particularly beneficial during pregnancy, a time when the digestive system is already sensitive. Because of its superior absorption and minimal laxative effect, Magnesium Glycinate is highly effective for addressing deficiencies and supporting muscle relaxation and better sleep.
In contrast, forms like Magnesium Oxide are not recommended for routine supplementation due to their low absorption rate. While Magnesium Citrate is well-absorbed, its potent laxative effect makes it less ideal for consistent daily use, unless a mild laxative action is desired. Prioritizing highly absorbable and easily tolerated chelated forms helps ensure the pregnant individual receives the intended therapeutic benefits.
Safe Dosage and Medical Guidance
It is important to consult a healthcare provider before beginning any new supplement regimen during pregnancy. The Recommended Dietary Allowance (RDA) for magnesium from all sources (food and supplements) increases during pregnancy.
Recommended Dietary Allowance (RDA)
The RDA for pregnant adults aged 19 to 30 is 350 milligrams (mg) per day. For those aged 31 to 50, the RDA is 360 mg per day.
Tolerable Upper Intake Level (UL)
The Tolerable Upper Intake Level (UL) for supplemental magnesium is set at 350 mg per day for all pregnant adults. This limit applies only to the magnesium consumed from supplements and medications, not the magnesium naturally present in food. Staying within this supplemental limit is necessary to avoid potential adverse effects.
Exceeding the recommended supplemental intake can lead to side effects, most commonly loose stools, diarrhea, or nausea. Individuals with impaired kidney function should exercise caution with magnesium supplements, as the kidneys are responsible for eliminating excess mineral from the body. A healthcare professional can determine the appropriate dosage tailored to an individual’s specific dietary intake, health status, and symptoms.