Can I Take Magnesium With Stage 3 Kidney Disease?
Magnesium is a vital mineral that helps regulate many body processes, including muscle function, nerve signaling, and blood pressure. If you have stage 3 chronic kidney disease (CKD), it's natural to wonder whether magnesium supplements are safe. The answer depends on your blood magnesium levels, overall kidney function, and whether you have other health concerns.
This article will explain how stage 3 kidney disease affects magnesium levels, what to know before taking supplements, and when to talk to a healthcare provider.
Understanding Magnesium
Magnesium is found in foods like leafy greens, whole grains, beans, and nuts. It's also available in supplements and some medications like antacids and laxatives. The kidneys help regulate magnesium by removing any excess through the urine.
In healthy people, this keeps blood levels in balance. But when kidneys aren’t working well as in stage 3 CKD magnesium levels can change.
What Is Stage 3 Kidney Disease?
Stage 3 CKD means your kidneys are moderately damaged. Your estimated glomerular filtration rate (eGFR) is between 30 and 59. At this stage, waste products and fluids may start to build up in your body. You might not have symptoms yet, but your lab values may show changes in minerals like potassium, calcium, and magnesium.
Learn more: The Complete Guide to At-Home Kidney Function Tests
How Kidney Disease Affects Magnesium
Your kidneys play a central role in keeping magnesium levels balanced. When they start to decline:
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You may absorb more magnesium than needed from food or supplements
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Your body may have trouble removing excess magnesium through urine
As a result, your magnesium levels can either be too low (hypomagnesemia) or too high (hypermagnesemia).
Too Much Magnesium
High magnesium levels can happen in CKD, especially if you're taking magnesium-containing supplements or medications. Signs may include:
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Nausea
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Weakness
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Low blood pressure
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Confusion
In severe cases, too much magnesium can be dangerous.
Too Little Magnesium
Some people with CKD may have low magnesium levels due to poor diet or medication side effects. Symptoms of low magnesium include:
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Muscle cramps or spasms
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Fatigue
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Irregular heartbeat
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Numbness or tingling
If your magnesium is low, your doctor may suggest supplements or dietary changes.
Should You Take Magnesium With Stage 3 CKD?
You shouldn’t take magnesium on your own without medical advice if you have kidney disease. Here’s why:
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Your kidneys may not clear extra magnesium effectively
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Magnesium can interact with other medications
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You might already be getting enough through diet
Your doctor may order blood tests to check your magnesium level. If it’s low, they may recommend a safe dose or form of magnesium.
If it’s high, you may need to avoid supplements and magnesium-rich antacids.
Safe Ways to Manage Magnesium in CKD
If you have stage 3 kidney disease and want to keep your magnesium levels in balance, here’s what you can do:
1. Get Regular Blood Tests
Magnesium levels are usually checked with other kidney labs. Your doctor may test magnesium along with calcium, potassium, and phosphorus.
2. Avoid Over-the-Counter Magnesium Without Approval
This includes:
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Antacids like milk of magnesia
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Laxatives containing magnesium (such as magnesium citrate)
Only take these if your doctor says they’re safe.
3. Review Your Diet
You may not need a supplement if you’re getting enough magnesium from food. Sources include:
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Leafy greens (spinach, kale)
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Nuts and seeds
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Beans and lentils
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Whole grains
But remember, some of these foods are also high in potassium or phosphorus. A dietitian can help you make choices that fit your kidney needs.
Related reading: Ribbon Checkup Urine Test: Simple At-Home Health Tracking
4. Watch for Symptoms
Report any new symptoms such as weakness, confusion, or irregular heartbeat to your doctor. These could be signs of a magnesium imbalance.
When to Talk to Your Doctor
Ask your healthcare provider about magnesium if:
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You are taking supplements or magnesium-containing medications
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You have symptoms of high or low magnesium
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Your recent blood tests showed abnormal magnesium levels
You may also need to adjust medications that affect magnesium, like certain diuretics or proton pump inhibitors.
Magnesium and Other Health Conditions
CKD often comes with other conditions, including diabetes, high blood pressure, or heart disease. These may affect your magnesium levels too.
Diabetes and Blood Sugar
People with diabetes may lose more magnesium in the urine. This can lead to low magnesium over time. Some research suggests magnesium may help with blood sugar control, but you should never take it without your provider’s input.
Learn more: Understanding Glucose in Urine: Causes, Symptoms, and Treatment
Digestive Issues
If you use laxatives for constipation, especially ones that contain magnesium, let your doctor know. Overuse can lead to dangerously high magnesium levels in CKD.
Liver or Urinary Tract Conditions
Liver or urinary tract health may also affect how your body processes minerals. If you have liver disease or frequent urinary tract infections (UTIs), you may need additional monitoring.
Takeaway
People with stage 3 kidney disease should be cautious with magnesium supplements and medications. Your kidneys may not process magnesium as well, increasing your risk of having too much in your system.
Before taking magnesium, talk to your doctor and get your blood levels checked. Diet, other medications, and chronic conditions like diabetes or liver disease can affect your magnesium needs.
Your care team can help you manage minerals safely through lab monitoring and a tailored nutrition plan.
Want to monitor your kidney health at home?
Try Ribbon Checkup's easy urine test kit to stay on top of kidney function and track any changes early.
Related sources
References
Correa, S., Guerra-Torres, X. E., Waikar, S. S., & Finnian R. Mc Causland. (2021). Serum Magnesium, Blood Pressure, and Risk of Hypertension and Chronic Kidney Disease Progression in the CRIC Study. Hypertension, 78(6), 1771–1780. https://doi.org/10.1161/hypertensionaha.121.17694
Cunningham, J., Rodriguez, M., & Messa, P. (2012). Magnesium in chronic kidney disease Stages 3 and 4 and in dialysis patients. Clinical Kidney Journal, 5(Suppl 1), i39–i51. https://doi.org/10.1093/ndtplus/sfr166
Iain Bressendorff, Hansen, D., Schou, M., Silver, B., Pasch, A., Bouchelouche, P., Pedersen, L., Rasmussen, L. M., & Brandi, L. (2016). Oral Magnesium Supplementation in Chronic Kidney Disease Stages 3 and 4: Efficacy, Safety, and Effect on Serum Calcification Propensity A Prospective Randomized Double-Blinded Placebo-Controlled Clinical Trial. Kidney International Reports, 2(3), 380–389. https://doi.org/10.1016/j.ekir.2016.12.008
Magnesium and Chronic Kidney Disease: An Essential Consideration. (2025, March 13). Renal and Urology News. https://www.renalandurologynews.com/features/magnesium-and-chronic-kidney-disease-an-essential-consideration/
Stage 3a Chronic Kidney Disease (CKD). (2025, September 7). National Kidney Foundation. https://www.kidney.org/kidney-topics/stage-3a-chronic-kidney-disease-ckd
