What is the Maximum Daily Dose of Magnesium?
By: Markita Lewis, MS, RD
Magnesium is a mineral that is essential for health, but sometimes gets overlooked in discussions about healthy eating.
Studies find that because of changes in soil and a reduced intake of fruits and vegetables, we may not be getting enough magnesium to support our health.1
Buying a magnesium supplement can be a shortcut to meeting shortfalls of your diet, but it doesn’t come without its own risks. There can be too much of a good thing.
Knowing what the appropriate amount of magnesium is for your body can help you stay healthy without experiencing bothersome side effects.
In this article you’ll learn more about:
- What magnesium is
- Natural sources of magnesium
- What magnesium does for the body
- How much magnesium is normal
- How much is too much magnesium and associated side effects
Let’s dive into why magnesium is important, and how to get a proper amount into your diet daily.
What is Magnesium?
Magnesium is a small mineral that is necessary for hundreds of reactions to occur in your body. It plays a role in building muscle, energy production, bone development, muscle contraction, nerve function, and the synthesis of helpful proteins.
Foods High In Magnesium
Magnesium is naturally found in a variety of beverages, plant-based foods, and animal products. Plant-based foods containing fiber tend to have the most magnesium per serving.
Some sources of magnesium include:
- Nuts and seeds (e.g., pumpkin seeds, chia seeds, almonds, cashews)
- Leafy green vegetables (e.g., spinach)
- Legumes (e.g., peanuts, black beans, kidney beans, lentils)
- Whole grains (e.g., cereal, brown rice, oatmeal)
- Dairy and dairy alternatives (e.g., soymilk, yogurt, milk)
Manufacturers often add magnesium to refined grains, breakfast cereals, and other fortified foods to make up for the magnesium lost during processing.
Beverages like tea and coffee have magnesium but contain the compounds tannins and chlorogenic acid which can reduce how much of the mineral is actually absorbed into your body.
Drinking tap, bottled, or mineral water can give you some magnesium, but the amount of magnesium will differ depending on brand and water type.
How Does Magnesium Benefit Your Body?
As the fourth most abundant mineral in your body, magnesium is a part of a wide variety of physical functions.
These are just a few of the benefits that magnesium has:
Magnesium can protect your heart by reducing inflammation, supporting muscle health, and keeping the heartbeat steady. Observational studies find that increased magnesium intake is associated with a lower risk of cardiovascular diseases like congestive heart failure, high blood pressure, and stroke.2
Metabolic syndrome is a cluster of factors associated with an increased risk for heart disease and type-2 diabetes.
Studies suggest that magnesium from foods and supplements may be protective against metabolic syndrome by reducing triglycerides, blood sugar, and blood pressure. 3
Magnesium can also be beneficial for a number of pain conditions by reducing sensitivity to pain.
Studies find that magnesium supplementation is shown to benefit patients with neuropathic pain, as well as reduce pain from conditions like fibromyalgia, migraines, headaches, and dysmenorrhea. 4
Magnesium supplementation may improve sleep and sleep quality by interacting with your muscles and neurotransmitters.
A 2021 review found that magnesium supplementation could improve sleep duration and quality for older adults with insomnia. Compared to a placebo, adults taking magnesium had significantly shorter sleep onset times. 5
Pregnant women who experience leg cramps at night may also benefit from taking a regular magnesium supplement. Magnesium supplementation slightly decreased the frequency of painful leg cramps during interventions.6
Dietary intake of magnesium may be a factor in mood disorders due to its roles in affecting neurotransmitter production and nerve signaling.
A 2019 study with over 17,000 participants from the 2007-2014 National Health and Nutrition Examination Survey (NHANES) examined the relationship between dietary magnesium and depression. In this study, researchers found an inverse association between dietary magnesium intake and the risk of depression.7
Magnesium needs are higher during physical activity to promote energy metabolism and normal muscle function.
A 2017 review on the relationship between magnesium and exercise performance found that magnesium supplementation could improve muscle performance and strength in both aerobic and anaerobic exercise conditions. 8
How Much Magnesium is Normal?
The Food and Nutrition Board at the Institute of Medicine developed Dietary Reference Intakes to determine how much magnesium it would take to meet the nutrient needs of most healthy individuals.
The Recommended Dietary Allowances for magnesium in adults are:
- Men 19+ years: 400-420 mg/day
- Women 19+ years: 310-320 mg/day
During pregnancy, magnesium needs are increased to 350 -360 mg/day.
Can You Take Too Much Magnesium?
Health risks from magnesium usually occur from dietary supplements or medications that contain magnesium.
Common side effects from taking excessive magnesium include diarrhea, nausea, and abdominal cramping.
Getting a large amount of magnesium from food typically does not cause any side effects because your kidneys are usually able to eliminate extra magnesium from the body.
It is for this reason that the Tolerable Upper Limit for magnesium includes only daily magnesium from dietary supplements and medications.9
The Tolerable Upper Intake Levels (ULs) for supplemental magnesium is the same for men and women:
- 9-18 years: 350mg/day
- 19+ years: 350mg/day
Very large doses of magnesium from supplements or medications like antacids and laxatives can cause magnesium toxicity.10
Side effects of magnesium toxicity include low blood pressure, depression, nausea and vomiting, muscle weakness, irregular heartbeat, urine retention, and cardiac arrest.
To reduce the risk of getting too much magnesium, avoid stand alone magnesium supplements unless advised to do so by your healthcare provider. Eating a variety of nuts and seeds, legumes, whole grains, dairy and dairy alternatives, fruits and vegetables, and other nutrient-dense foods can help you meet your daily needs.
In the US, over half the population falls below daily requirements for magnesium according to the Dietary Guidelines for Americans. Other micronutrients that are under-consumed include vitamin D, vitamin E, vitamin C, vitamin A and calcium. A high quality multivitamin and mineral will provide approximately 100-200 mg of magnesium and fill the gaps for these other micronutrients.
- Razzaque MS. Magnesium: Are We Consuming Enough?. Nutrients. 2018;10(12):1863. doi:10.3390/nu10121863
- Tangvoraphonkchai K, Davenport A. Magnesium and Cardiovascular Disease. Adv Chronic Kidney Dis.2018;25(3):251-260. doi:10.1053/j.ackd.2018.02.010
- Piuri G, Zocchi M, Della Porta M, et al. Magnesium in Obesity, Metabolic Syndrome, and Type 2 Diabetes. Nutrients. 2021;13(2):320. doi:10.3390/nu13020320
- Shin HJ, Na HS, Do SH. Magnesium and Pain. Nutrients. 2020;12(8):2184. doi:10.3390/nu12082184
- Mah J, Pitre T. Oral magnesium supplementation for insomnia in older adults: a Systematic Review & Meta-Analysis. BMC Complement Med Ther. 2021;21(1):125. doi:10.1186/s12906-021-03297-z
- Sebo P, Cerutti B, Haller DM. Effect of magnesium therapy on nocturnal leg cramps: a systematic review of randomized controlled trials with meta-analysis using simulations. Fam Pract. 2014;31(1):7-19. doi:10.1093/fampra/cmt065
- Sun C, Wang R, Li Z, Zhang D. Dietary magnesium intake and risk of depression. J Affect Disord. 2019;246:627-632. doi:10.1016/j.jad.2018.12.114
- Zhang Y, Xun P, Wang R, Mao L, He K. Can Magnesium Enhance Exercise Performance?. Nutrients. 2017;9(9):946. doi:10.3390/nu9090946
- Magnesium - health professional fact sheet. National Health Institute Office of Dietary Supplements. https://ods.od.nih.gov/factsheets/Magnesium-healthProfessional/. Updated August 11, 2021. Accessed January 15, 2022.
- Van Laecke S. Hypomagnesemia and hypermagnesemia. Acta Clin Belg. 2019;74(1):41-47. doi:10.1080/17843286.2018.1516173