Recommended Daily Magnesium Intake
For healthy adults, the recommended daily magnesium intake is 320 mg for women and 420 mg for men, based on the Institute of Medicine's Dietary Reference Intake guidelines. 1
Standard Daily Requirements by Population
Healthy Adults
- Women: 320 mg/day 1
- Men: 420 mg/day 1
- These values represent the Recommended Dietary Allowance (RDA) established by the Institute of Medicine 1
Children and Adolescents
Special Populations
- Pregnant or lactating women: Add an additional 150 mg/day to baseline requirements (total approximately 470 mg/day) 2
- Lactating women: 3 mg/day adequate intake 3
Important Safety Threshold
The Tolerable Upper Intake Level (UL) for supplemental magnesium is 350 mg/day to avoid adverse effects such as diarrhea and gastrointestinal intolerance. 1 This limit applies specifically to magnesium from supplements, not from food sources 1.
Clinical Context and Real-World Intake
Research demonstrates that actual magnesium intake often falls short of recommendations. Studies show average daily intakes of approximately 228 mg/day for women and 331 mg/day for men in the United States, with even lower intakes among Black Americans 2. In other populations, average intake was found to be 279.2 mg/day (90.4% of recommended intake), with 54.8% of subjects consuming less than the estimated average requirement 4.
Dietary Sources vs. Supplementation
Magnesium should preferably be obtained through food sources rather than supplements, as dietary sources provide additional beneficial nutrients. 3 Foods rich in magnesium include whole grains, nuts, legumes, leafy vegetables, and certain seafood 3.
When Supplementation May Be Considered
- Individuals with documented deficiency 1
- Patients with malabsorption conditions 1
- Elderly individuals 1
- Strict vegetarians 1
- Those on calorie-restricted diets 1
Common Pitfall
Do not exceed 350 mg/day from supplements, as this increases risk of diarrhea, abdominal distension, and gastrointestinal intolerance. 1 The 350 mg upper limit does not include magnesium obtained from food sources, only from supplemental forms 1.