From the FDA Drug Label
DIRECTIONS Antacid Directions:■ take 1 tablet twice a day or as directed by a physician Magnesium Supplement Directions: ■take 1 to 2 tablets daily or as directed by a physician Directions shake well before using drink a full glass (8 ounces) of liquid with each dose may be taken as a single daily dose or in divided doses adults and children 12 years of age and over - 6.5 to 10 fl oz maximum 10 fl oz in 24 hours
The safe dosage of magnesium for adults is:
- 1 to 2 tablets daily of magnesium oxide (PO) as directed by a physician 1
- 6.5 to 10 fl oz of magnesium citrate (PO) per day, with a maximum of 10 fl oz in 24 hours 2
From the Research
The safe dosage of magnesium for adults is between 383-398 mg per day for women and 463-491 mg per day for men, as recommended by the most recent study 3.
Key Considerations
- The recommended daily allowance (RDA) of magnesium has been updated to reflect the increasing body weights of adults, with a corresponding increase in magnesium requirements 3.
- For supplementation, doses typically range from 200-400 mg per day, which is generally considered safe for most healthy adults.
- Upper tolerable intake levels are set at 350 mg per day for supplemental magnesium (not including food sources) to avoid digestive side effects like diarrhea and stomach cramps.
- Different forms of magnesium have varying absorption rates and effects - magnesium citrate and glycinate are often better absorbed and gentler on the stomach than magnesium oxide.
Important Factors to Consider
- People with kidney disease should consult their healthcare provider before supplementing as the kidneys regulate magnesium levels in the body.
- Magnesium is essential for over 300 biochemical reactions including muscle and nerve function, blood glucose control, and bone health, which is why maintaining adequate levels is important for overall health.
- If taking supplements, it's best to divide doses throughout the day with meals to improve absorption and reduce gastrointestinal discomfort.
Evidence-Based Recommendations
- A systematic review of clinical trials found that magnesium supplementation can be effective in preventing migraines, with a recommended dose of 600 mg per day 4.
- Another study found that magnesium pidolate may have high bioavailability and good penetration at the intracellular level, making it a potentially effective treatment for headaches and migraines 5.
- The most recent study on magnesium requirements found that the current RDAs are inadequate and need to be updated to reflect the increasing body weights of adults 3.