Is magnesium safe during pregnancy?

What does the evidence say about magnesium during pregnancy?

1. The recommended amount of magnesium during pregnancy is 350 to 360 mg a day, a bit higher than for someone who isn't pregnant. 1
2. The upper limit for magnesium from supplements is 350 mg a day, and that ceiling applies only to supplements, not to magnesium you get from food. 2
3. Going over the supplement upper limit most commonly causes diarrhea, nausea, and abdominal cramping, so starting low and adjusting the dose matters even within the 'safe' range. 1
4. Oral magnesium supplements can interact with several medications, including bisphosphonates, certain antibiotics, and some diuretics, so check with your pharmacist before adding it to other prescriptions. 1

Is magnesium safe in each trimester?

• First trimester. Most prenatal vitamins supply a modest amount of magnesium. Total intake up to 350-360 mg a day hasn't been linked to any specific first-trimester risk.
• Second trimester. The same guidance applies. Some providers add a magnesium supplement, like glycinate or citrate, for leg cramps, constipation, or restless legs.
• Third trimester. The same guidance applies. IV magnesium sulfate is a completely different, hospital-administered intervention used for preterm labor or preeclampsia, not something to confuse with an over-the-counter oral supplement.