Magnesium in your pregnancy diet

Why you need magnesium during pregnancy

When you're pregnant, magnesium helps build and repair your body's tissues. A severe deficiency during pregnancy may lead to preeclampsia, poor fetal growth, and even infant mortality.

Magnesium and calcium work in combination: Magnesium relaxes muscles, while calcium stimulates muscles to contract. Research suggests that proper levels of magnesium during pregnancy can help keep the uterus from contracting prematurely.

Magnesium also helps build strong bones and teeth, regulates insulin and blood sugar levels, and helps certain enzymes function. Research indicates it may help control cholesterol and irregular heartbeats. Magnesium may also be helpful in reducing leg cramps.

How much magnesium you need

Pregnant women, 19 to 30 years of age: 350 milligrams (mg) of magnesium per day
Pregnant, 18 and younger: 400 mg
Pregnant, 31 and older: 360 mg
Breastfeeding women, 19 to 30: 310 mg
Breastfeeding, 18 and younger: 360 mg
Breastfeeding, 31 and older: 320 mg

You don't have to get the recommended amount of magnesium every day. Instead, aim for that amount as an average over the course of a few days or a week.

Food sources of magnesium

Magnesium is plentiful in seeds, whole grains, some fish, leafy green vegetables, and some legumes. Some common food sources:

• 1 ounce pumpkin seeds: 151.9 mg
• 1/4 cup raw sunflower seeds: 127.4 mg
• 1 cup cooked millet: 105.6 mg
• 3 ounces chinook salmon, baked or broiled: 103.8 mg
• 1/2 cup bran cereal: 93.1 mg
• 1/3 cup wheat germ: 90.9 mg
• 3 ounces halibut: 90.0 mg
• 1/2 cup cooked quinoa: 89.3 mg
• 1 cup spinach spaghetti: 86.6 mg
• 1 cup cooked brown rice: 86.0 mg
• 1/2 cup boiled Chinese long beans: 84.3 mg
• 1 ounce dry roasted almonds: 80.0 mg
• 1/2 cup frozen spinach, cooked and drained: 78 mg
• 1/3 cup tofu: 76.1 mg
• 1 ounce dry roasted cashews: 75.0 mg
• 1/2 cup cooked soybeans: 75.0 mg
• 1/2 cup cooked spinach: 75.0 mg
• 1/2 cup boiled Swiss chard: 75.3 mg
• 1/2 cup cooked black beans: 60.2 mg
• 1 cup fortified instant oatmeal, prepared with water: 55.0 mg
• 1 medium baked potato, with skin: 50.0 mg
• 2 tablespoons smooth peanut butter: 50.0 mg
• 1/2 cup cooked navy beans: 47.0 mg
• 1 cup nonfat plain yogurt: 45.0 mg
• 1/2 cup vegetarian baked beans: 40.0 mg

(Note that 3 ounces of meat is about the size of a deck of cards.)

Should you take a magnesium supplement?

Maybe. It's not hard to meet your magnesium requirement with a healthy, varied diet, and magnesium is included in some prenatal vitamin supplements. Still, if your diet isn't great or you haven't been able to eat much, you may be falling short. Talk with your healthcare provider about taking a supplement if you think you're not getting enough.

The signs of a magnesium deficiency

Signs of a magnesium deficiency include nausea, vomiting, loss of appetite, fatigue, insomnia, muscle twitching, poor memory, irregular heartbeat, and weakness.