Natural Medical SolutionsMagnesium is a mineral your body needs to work properly. It helps run your muscles and nerves, and it plays a part in blood sugar, blood pressure, and building protein, bone and DNA.
What does magnesium do?
It is a nutrient your body needs to stay healthy. It has a lot of jobs at once:
- Keeping your muscles and nerves working
- Helping control blood sugar
- Helping control blood pressure
- Making protein, bone and DNA
How much magnesium do you need?
It depends on your age and sex. Here are the daily amounts:
- Men: 400 to 420 mg
- Women: 310 to 320 mg
- Pregnant women: 350 to 360 mg
- Breastfeeding women: 310 to 320 mg
- Teen boys 14 to 18: 410 mg
- Teen girls 14 to 18: 360 mg
- Children 9 to 13: 240 mg
- Children 4 to 8: 130 mg
- Children 1 to 3: 80 mg
Can you take too much magnesium?
Yes, but only from supplements and medicines. What occurs naturally in food and drink is not harmful. You do not need to limit it. In healthy people the kidneys clear any extra.
The adult upper limit is 350 mg a day from supplements and medicines. For children it is:
- Ages 9 to 18: 350 mg
- Ages 4 to 8: 110 mg
- Ages 1 to 3: 65 mg
You may notice the upper limit is lower than the daily amount. That looks wrong. It is not. The two numbers count different things:
- The daily amount counts every source, food and drink included.
- The upper limit counts only supplements and medicines.
Too much from supplements can cause diarrhea, feeling sick and stomach cramps. Very high amounts can cause an uneven heartbeat, and the heart can stop.
Who should be careful with magnesium?
Check with your doctor before you take it if any of these apply:
- You take medicine for osteoporosis
- You take antibiotics
- You take a water pill (a diuretic)
- You take acid reflux or ulcer medicine long term
- You take high dose zinc
The reasons are below. Do not go above the upper limit unless your doctor says so.
Does Magnesium interact with any medications?
Talk to your doctor and pharmacist before taking magnesium if you take any prescription medicine. The list below is not complete.
Your body takes these up poorly if you take them too close to a high dose. Space them apart.
Your body may not take up some antibiotics if you take them too close to a dose.
These change how much you lose in urine. Some raise it, some lower it. It depends on the type.
Taken for a long time, drugs for acid reflux or ulcers can leave your blood level too low.
Very high doses of zinc get in the way of how your body takes up and controls it.
Common questions about magnesium
Why is the magnesium upper limit lower than the recommended amount?
Can you get too much magnesium from food?
What happens if you take too much magnesium?
Does magnesium affect antibiotics?
Related on this site
Where this information comes from
Written from NIH Office of Dietary Supplements, a public-domain resource from the U.S. National Institutes of Health. Information retrieved 2026-08-21.
Ready to heal naturally?
Start your personalized naturopathic, functional & holistic care plan in Roswell, GA, proudly serving Alpharetta, Atlanta & the north metro.
