This information explains how to get the daily recommended amount of magnesium you need to stay healthy.

What is magnesium?

Magnesium is an essential mineral in the body that:

  • Helps keep your heart rhythm steady
  • Helps maintain normal muscle and nerve function
  • Works with other minerals to maintain strong bones and overall good health

Magnesium can be given as a supplement orally (by mouth) or intravenously (IV, through a vein).

Low levels of magnesium in the body can be caused by:

  • Having chronic or excessive vomiting or diarrhea
  • Having problems absorbing nutrients in the stomach or intestines
  • Not eating enough food with magnesium
  • Taking some medications, such as certain diuretics, antibiotics, or chemotherapies. These medications can increase the loss of magnesium through the urine.

How much magnesium do I need every day?

A normal amount of magnesium in the blood is 1.4 to 2.2 mEq/L. If your magnesium level is low, your doctor, nurse practitioner (NP), or physician assistant (PA) may give you a prescription for a magnesium supplement to take by mouth or you may be given it through an IV.

The table below from the National Institutes of Health (NIH) shows the daily recommended amounts of magnesium for children and adults.

Age
(years)

Males
(mg/day)

Females
(mg/day)

Pregnant Females
(mg/day)

Lactating Females
(mg/day)

1 to 3

80

80

N/A N/A

4 to 8

130

130

N/A N/A

9 to 13

240

240

N/A N/A

14 to 18

410

360

400

360

19 to 30

400

310

350

310

31 or older

420

320

360

360

What are food sources of magnesium?

Eating foods with magnesium can help increase the amount in your body. Eating a variety of whole grains, legumes (such as peas and beans), and dark green, leafy vegetables every day will help you get your daily recommended amount of magnesium. The table below lists a variety of foods and the amount of magnesium in each one.

Food

Serving Size

Amount of Magnesium (mg)

% DV*

Halibut (cooked)

3 ounces

90

20

Almonds (dry roasted)

1 ounce

80

20

Cashews (dry roasted)

1 ounce

75

20

Soybeans (cooked)

½ cup

75

20

Spinach (frozen, cooked)

½ cup

75

20

Mixed nuts (dry roasted)

1 ounce

65

15

Shredded wheat cereal

2 rectangular biscuits

55

15

Oatmeal (instant, fortified, and prepared with water)

1 cup

55

15

Potato (baked with skin)

1 medium

50

15

Peanuts (dry roasted)

1 ounce

50

15

Peanut butter (smooth)

2 tablespoons

50

15

Wheat bran, crude (raw)

2 tablespoons

45

10

Black-eyed peas (cooked)

½ cup

45

10

Yogurt, plain, skim milk

8 fluid ounces

45

10

Bran flakes

½ cup

40

10

Baked beans (vegetarian)

½ cup

40

10

Brown rice (long-grain, cooked)

½ cup

40

10

Lentils (cooked)

½ cup

35

8

Avocado (California)

½ cup pureed

35

8

Kidney beans (cooked)

½ cup

35

8

Pinto beans (cooked)

½ cup

35

8

Wheat germ, crude (raw)

2 tablespoons

35

8

Chocolate milk

1 cup

33

8

Banana (raw)

1 medium

30

8

Milk chocolate candy bar

1.5 ounce bar

28

8

Milk (2% or skim)

1 cup

27

8

Whole milk

1 cup

24

6

Whole-wheat bread (commercially prepared)

1 slice

25

6

Raisins

½ cup, packed

25

6

Chocolate pudding

4 ounces, ready-to-eat portion

24

6

*DV=Daily Value. A DV is a percentage of the total daily recommended amount. A food that provides 20% of the DV per serving is high in magnesium.

How can I speak with a dietitian?

If you have any questions or concerns about your diet while you are in the hospital, ask to see a dietitian. If you have already been discharged and have questions, call (212) 639-7312. To schedule an appointment to see a dietitian, call (212) 639-7071.