Is magnesium safe during pregnancy?

What does the evidence say about magnesium during pregnancy?

1. The recommended dietary allowance in pregnancy is 400 mg a day at ages 14 to 18, 350 mg at ages 19 to 30, and 360 mg at ages 31 to 50. 1
2. The 350 mg upper limit covers magnesium from dietary supplements and medications only. It does not include magnesium found naturally in food and beverages, which is why the limit can sit below the daily target without contradiction. 1
3. Too much magnesium from food does not pose a risk in healthy people because the kidneys clear the excess, but high doses from supplements or medications cause diarrhea, nausea, and abdominal cramping. 1
4. Evidence for oral magnesium and pregnancy-related leg cramps is of very low certainty and conflicting, and gastrointestinal side effects, mainly diarrhea, were reported by 11 to 37 percent of people taking it. 2
5. About 53.3 percent of pregnant women in the United States take in less magnesium from food than the estimated average requirement, with a mean dietary intake of 294 mg a day. 3

Is magnesium safe in each trimester?

• First trimester. The target is in place from the start. Magnesium supplements loosen stools at higher doses, which some people welcome and others do not, so start low if you begin one during a nauseous stretch.
• Second trimester. Leg cramps often show up around now and magnesium is the usual suggestion. The evidence behind that specific use is weak, so count it as worth trying rather than reliably effective.
• Third trimester. Cramps and constipation both tend to peak here. Magnesium oxide draws more water into the bowel than magnesium glycinate does, which is why the form on the label changes what you feel.