Skip to content

    How much magnesium should you take?

    The recommended dietary allowance (RDA) includes the magnesium you get from both the food you eat and any supplements you take.


    Recommended Dietary Allowance (RDA)


    1-3 years

    80 mg/day

    4-8 years

    130 mg/day

    9-13 years

    240 mg/day


    14-18 years

    360 mg/day

    19-30 years

    310 mg/day

    31 years and over

    320 mg/day


    Under 19 years: 400 mg/day
    19 to 30 years: 350 mg/day
    31 years and up: 360 mg/day


    Under 19 years: 360 mg/day
    19 to 30 years: 310 mg/day
    31 years and up: 320 mg/day


    14-18 years

    410 mg/day

    19-30 years

    400 mg/day

    31 years and up

    420 mg/day

    It's safe to get high levels of magnesium from food. But excessive use of magnesium supplements can be toxic. The upper limit -- the highest dose a person can take -- of magnesium supplements is:

    • 65 mg/day for children ages 1-3
    • 110 mg/day for children ages 4-8
    • 350 mg/day for adults and children ages 9 and up

    These doses are the highest somebody should add to his or her diet.


    Can you get magnesium naturally from foods?

    Natural food sources of magnesium include:

    • Green, leafy vegetables, like spinach
    • Nuts
    • Beans, peas, and soybeans
    • Whole-grain cereals

    Eating whole foods is always best. Magnesium can be lost during refinement and processing.

    What are the risks of taking magnesium?

    • Side effects. Magnesium supplements can cause nausea, cramps, and diarrhea. Magnesium supplements often cause softening of stool.
    • Interactions. Magnesium supplements may not be safe for people who take diuretics, heart medicines, or antibiotics. Check with your health care provider if you are taking any medicine before taking magnesium.
    • Risks. People with diabetes, intestinal disease, heart disease or kidney disease should not take magnesium before speaking with their health care provider.
    • Overdose. Signs of a magnesium overdose can include nausea, diarrhea, low blood pressure, muscle weakness, and fatigue. At very high doses, magnesium can be fatal.

    WebMD Medical Reference

    Healthy Recipe Finder

    Browse our collection of healthy, delicious recipes, from WebMD and Eating Well magazine.

    Top searches: Chicken, Chocolate, Salad, Desserts, Soup

    Heart Rate Calculator

    Ensure you're exercising hard enough to get a good workout, but not strain your heart.

    While you are exercising, you should count between...