Magnesium Citrate 600 mg Daily in Pregnancy Safety
Magnesium citrate 600 mg daily is generally safe during pregnancy, though the FDA drug label advises consulting a healthcare professional before use, and current evidence supports magnesium supplementation for specific pregnancy benefits without significant safety concerns at this dose. 1
Safety Profile
The FDA-approved drug label for oral magnesium citrate states that pregnant women should "ask health professional before use," which is standard precautionary language rather than a contraindication. 1 This reflects the general safety profile of oral magnesium supplementation during pregnancy when used appropriately.
Magnesium supplementation during pregnancy has been extensively studied without evidence of maternal or fetal harm at therapeutic doses. 2 A Cochrane systematic review including 9,090 women found no increased risk of adverse maternal or fetal outcomes with oral magnesium supplementation, though doses and formulations varied across studies. 2
Dosing Context
Your proposed dose of 600 mg magnesium citrate daily falls within the range studied in clinical trials:
- Magnesium citrate at 365 mg daily has been used safely from early pregnancy (≤18 weeks) until late gestation. 2
- Magnesium citrate at 340 mg daily from 9-27 weeks' gestation showed no safety concerns. 2
- The recommended dietary allowance for magnesium in pregnancy is 450 mg, yet most pregnant women consume only 35-58% of this amount (approximately 157-261 mg). 3
Clinical Benefits
The American College of Obstetricians and Gynecologists recommends magnesium supplementation during pregnancy to reduce preeclampsia risk in high-risk women, particularly when combined with calcium supplementation in those with low dietary calcium intake. 4
Additional potential benefits include:
- Reduced risk of preterm birth, low birth weight, and small-for-gestational age infants in some studies, though high-quality evidence is limited. 2, 5
- Fewer hospitalizations during pregnancy and reduced antepartum hemorrhage in supplemented women. 5
- Lower rates of fetal growth restriction, pregnancy-induced hypertension, and gestational diabetes in one randomized trial using 200 mg effervescent magnesium plus 100 mg from multivitamins (total 300 mg daily). 6
Important Caveats
The one concerning finding from the Cochrane review—a possible increased risk of neonatal death (RR 2.21)—was driven by congenital anomalies unlikely related to magnesium and extreme prematurity in twins; when these cases were excluded, no increased risk remained. 2 This should not deter appropriate supplementation but warrants awareness.
Magnesium deficiency is prevalent in women of childbearing age, and pregnancy increases magnesium requirements that most women do not meet through diet alone. 7, 3 Dietary sources (nuts, seeds, beans, leafy greens) should be encouraged alongside supplementation. 7
Practical Recommendations
- Magnesium citrate 600 mg daily is reasonable for pregnancy supplementation, particularly in women with inadequate dietary intake or risk factors for preeclampsia. 4, 7
- This dose is higher than amounts typically found in prenatal vitamins (usually ≤100 mg) and addresses the common dietary shortfall. 3
- Avoid confusion with intravenous magnesium sulfate protocols used for eclampsia prevention or neuroprotection, which involve much higher doses and different safety considerations. 4, 8, 9
- Women with renal impairment require careful monitoring due to reduced magnesium excretion and toxicity risk, though this primarily applies to IV administration. 8
The evidence supports safety of oral magnesium citrate supplementation at 600 mg daily during pregnancy, with potential benefits for maternal and fetal outcomes and no established harm at this dose level.