Magnesium in your pregnancy diet
Why you need magnesium during pregnancy
Magnesium and calcium work in combination: Magnesium relaxes muscles, while calcium stimulates muscles to contract. Research suggests that getting adequate magnesium during pregnancy can help prevent the uterus from contracting prematurely.
Magnesium also helps build strong teeth and bones in your baby.
How much magnesium you need
Pregnant women age 18 and younger: 400 milligrams (mg) per day
Pregnant women ages 19 to 30: 350 mg per day
Pregnant women age 31 and older: 360 mg per day
Breastfeeding women age 18 and younger: 360 mg per day
Breastfeeding women ages 19 to 30: 310 mg per day
Breastfeeding women age 31 and older: 320 mg per day
Nonpregnant women ages 19 to 30: 310 mg per day
Nonpregnant women age 31 and older: 320 mg per day
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 include:
- 1/2 cup bran cereal: 112 mg
- 1/2 cup dry oat bran cereal: 96 mg
- 1 cup medium grain brown rice: 86 mg
- 3 ounces mackerel, cooked: 82 mg
- 1/2 cup frozen spinach, chopped and cooked: 78 mg
- 1 ounce almonds: 77 mg
- 1/2 cup large lima beans, cooked: 63 mg
- two biscuits shredded wheat cereal: 61 mg
- 1 ounce peanuts: 48 mg
- 1 tablespoon blackstrap molasses: 48 mg
- 1 ounce hazelnuts: 46 mg
- 1/2 cup frozen okra, cooked: 37 mg
- 8 ounces low-fat milk: 34 mg
- one medium banana: 32 mg
Should you take a magnesium supplement?
Probably not. It’s not hard to meet your magnesium requirement with a healthy, varied diet, and magnesium is included in some prenatal vitamin supplements. But you may be falling short if your diet isn’t great or you haven’t been able to eat much. Talk with your healthcare provider about taking a supplement if you think you’re not getting enough.
Magnesium deficiency is rare, but signs include nausea, vomiting, loss of appetite, fatigue, insomnia, muscle twitching, poor memory, irregular heartbeat, and weakness.
IOM. 1997. Dietary Reference Intakes for calcium, phosphorus, magnesium, vitamin d, and fluoride. Food and Nutrition Board, Institute of Medicine, National Academies. http://www.nap.edu/read/5776/chapter/8 [Accessed July 2016]
LPI. 2014. Magnesium. Linus Pauling Institute. http://lpi.oregonstate.edu/mic/minerals/magnesium [Accessed July 2016]
ODS. 2016. Magnesium. U.S. Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/ [Accessed July 2016]
UpToDate. 2015. Headache in pregnant and postpartum women. [Accessed July 2016]