How Much Magnesium Can a Pregnant Woman TakeMagnesium is another unsung hero of the nutrient world surrounded by a lot of hype, much of which is unproven or has been debunked.  Other than that, there isn’t a lot of information about magnesium’s role in pregnancy.

We do know that without magnesium, bones don’t grow and repair properly, blood pressure doesn’t regulate properly, and neural tissue doesn’t function as it should.  In the digestive tract, magnesium lowers stomach acid levels and acts as a laxative and as an anti-inflammatory.  Without enough magnesium in the diet, you’re at increased risk of various cancers, heart disease, osteoporosis, and diabetes.

The big question:  “Should I supplement with magnesium?”

The answer in a nutshell:  “Not without medical advice.”

During pregnancy, magnesium IVs or shots have been used to treat eclampsia and hypertension as well as stop preterm labor (by slowing contractions of the uterine muscle), seizures, and bad asthma attacks. The FDA announced in May, 2013, however, that using this treatment for more than five to seven days resulted in infants suffering impaired respiratory or neuromuscular response and being born with unacceptably low calcium levels in the bones that led to osteopenia (bone fractures) in some cases.  Based on evidence of harm to the baby, magnesium sulfate was reclassified from Class A (safe) to Class D (positive proof of harm but on a case by case basis, the benefit to mother and/or child might outweigh the harm).

There’s a whole laundry list of ailments and complaints that magnesium is supposed to be effective against, but many of them did not pan out in scientific testing.  A study published in the American Journal of Obstetrics and Gynecology showed no difference in outcome in rates of pregnancy-induced hypertension, miscarriage or stillbirth, birth weights, pre-eclampsia, pre-mature labor, gestational age at delivery, and babies admitted to the NICU.  It was also not proven effective as a treatment for ADHD, autism, prevention of heart attack, or atrial fibrillation.

It has shown to be effective to a greater or lesser degree in stopping pregnancy-induced leg cramps,  preventing migraines, correcting hearing loss caused too much loud noise, preventing kidney stones, lowering hypertension, treating angina, and preventing or reducing the severity of period cramps and PMS.

While magnesium deficiency is thought to be common, severe deficiencies are not common at all.  They’re usually found in those who suffer from digestive diseases like Crohn’s, kidney disease, have problems with the parathyroid gland, are on certain prescriptions (such as antibiotics or those to treat cancer or diabetes), abuse alcohol, use proton pump inhibitors such as Prilosec or Prevacid to treat acid reflux, or are older.  In such cases, medical providers might recommend a prescription supplement.

In addition to a well-balanced diet and after due medical consultation, pregnant women under 19 can supplement with no more than 400mg/day; pregnant women 19 to 30 with 350mg/day; and over 30s with 360mg/day.  Be aware that, aside from accidental toxicity (by, for example, not realizing that your favorite antacid contains magnesium – think of Milk of Magnesia!), magnesium can present you with certain side effects including: nausea, cramps, softened stools or even outright diarrhea.

To avoid the risks of magnesium toxicity, get it from your diet by including:
・  green leafies
・  nuts
・  legumes
・  and whole grain baked goods and cereals

The signs of magnesium toxicity run along the lines of muscle weakness, nausea, exhaustion, diarrhea, and hypotension (blood pressure that’s too low).  In a worst case scenario, magnesium overdose can be fatal, which is why you must keep it well out of reach of children (especially if it’s a tasty chewable antacid that might resemble candy to a child).

Magnesium is one of those supplements you should source from your diet and from the prenatal vitamin prescribed by your health care provider.  If your prenatal vitamin lacks magnesium, evaluate your diet – you could very well just save yourself the money and have one less pill to take.