Safety of Magnesium Glycinate 120mg with Normal Serum Levels
Yes, it is safe to take magnesium glycinate 120mg elemental with your current magnesium level of 2.3 mg/dL, as this dose falls well below the tolerable upper intake level and your renal function appears normal based on the normal magnesium level. 1
Key Safety Considerations
Your serum magnesium of 2.3 mg/dL is within the normal range (1.6-2.6 mg/dL) and well above the threshold where symptoms typically occur (<1.2 mg/dL). 2 However, normal serum magnesium does not exclude the possibility of total body magnesium depletion, as less than 1% of total body magnesium is found in blood. 1, 3
Dosing Context
The 120mg elemental magnesium you're considering is:
- Below the Recommended Daily Allowance of 320mg for women and 420mg for men 1
- Well below the Tolerable Upper Intake Level of 350mg/day from supplements 1
- Significantly lower than therapeutic doses used in clinical trials (480-960mg daily for deficiency states) 1
Critical Contraindications to Rule Out
You must avoid magnesium supplementation entirely if: 1, 4, 5
- Creatinine clearance <20 mL/min (life-threatening hypermagnesemia risk)
- Kidney disease or magnesium-restricted diet
- Current stomach pain, nausea, or vomiting
Magnesium Glycinate Advantages
Magnesium glycinate is an excellent choice for general supplementation because it has superior bioavailability compared to inorganic forms like magnesium oxide and causes fewer gastrointestinal side effects. 6 The organic salt formulation is better absorbed and better tolerated than magnesium oxide or hydroxide. 1, 6
Practical Administration
Take the magnesium glycinate at night when intestinal transit is slowest to maximize absorption. 1 This timing optimization is particularly important for organic magnesium salts. 1
Monitoring Recommendations
While routine monitoring is not necessary for this low supplementation dose in someone with normal baseline levels, recheck magnesium levels 2-3 weeks after starting if you develop any symptoms such as diarrhea, abdominal distension, or muscle cramps. 1 For stable maintenance supplementation at this dose, monitoring every 3 months is reasonable if you have risk factors for deficiency. 1
Common Pitfalls to Avoid
- Don't assume normal serum magnesium means you don't need supplementation - serum levels don't reflect total body stores 1, 3
- Watch for drug interactions if you're taking prescription medications, particularly diuretics, proton pump inhibitors, or digoxin 5, 1
- Stop use and consult a physician if you develop rectal bleeding or persistent constipation changes 5
When to Seek Medical Attention
Stop supplementation and contact your doctor if you experience: 5
- Signs of magnesium toxicity (hypotension, drowsiness, muscle weakness) 4
- Persistent diarrhea or gastrointestinal symptoms
- No improvement in symptoms after 1 week if taking for a specific indication
The 120mg elemental dose is conservative and safe for someone with your normal magnesium level, assuming normal kidney function. The organic glycinate form minimizes gastrointestinal side effects while providing good bioavailability. 6