Medically reviewed by Femi Aremu, PharmD
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- Caffeine’s diuretic nature may lower magnesium levels in your body.
- Low magnesium levels can cause muscle cramps, anxiety, and weakness.
- Eating more magnesium-rich foods can help balance caffeine’s effects.
Caffeine depletes magnesium levels by increasing fluid loss. This diuretic effect may cause unwanted health issues.
What’s the Connection Between Caffeine and Magnesium?
Your kidneys regulate the magnesium in your body by keeping what you need (or reabsorbing) and removing what you don't need through your urine.
Caffeine can disrupt this process in the following ways:
- Caffeine is a natural diuretic, meaning it helps your body eliminate fluids and electrolytes through your urine. Your body loses about 1.17 milliliters of water for every milligram (mg) of caffeine consumed.
- Diuretics cause your kidneys to flush out more magnesium before your body can absorb it. This can lead to low magnesium levels.
- Caffeine may affect how well your intestines absorb magnesium, potentially lowering magnesium levels.
That said, there is conflicting data on whether magnesium loss improves or worsens if you regularly consume caffeine.
Some experts believe your body adjusts to regular caffeine intake over time, so you don't lose as much fluid. Others believe that regularly consuming caffeine increases your risk of fluid and magnesium absorption issues. More research is needed to understand this relationship.
What Are the Risks of Low Magnesium?
Magnesium deficiency (or hypomagnesemia) affects nearly half of people in the U.S. Possible hypomagnesemia symptoms include:
- Arrhythmia (abnormal heartbeat)
- Fatigue
- Anxiety, stress, or mood changes
- Loss of appetite
- Nausea or vomiting
- Muscle cramps or spasms
- Seizures
- Weakness
Severely low magnesium can also lower other electrolyte levels, like calcium and potassium.
How Much Caffeine Is Safe?
The effects of caffeine may vary based on your individual sensitivity and how quickly it is eliminated from your body.
According to the United States Food and Drug Administration (FDA):
- Safe: Up to 400 milligrams (mg) of caffeine per day for most adults.
- Too much: Around 1,200 mg can cause dangerous effects, like seizures.
Common sources of caffeine include:
- Coffee (8 oz): 95-200 mg
- Energy drink (8 oz): 70-100 mg
- Tea (8 oz): 14-60 mg
- Soda (12 oz): 35-45 mg
| What Is the Recommended Magnesium Intake? | |
|---|---|
| Males (19-30 years) | 400 mg |
| Males (31+ years) | 420 mg |
| Females (19-30 years) | 310 mg |
| Females (31+ years) | 320 mg |
| Pregnant people (19-30 years) | 350 mg |
| Pregnant people (31-50 years) | 360 mg |
What Else Can Lower Magnesium?
In addition to caffeine, the following factors may reduce your magnesium levels:
- Poor diet or malnutrition
- Fluid loss (such as from heavy sweating or diarrhea)
- Medical conditions that affect nutrient absorption
- Excessive urination
- Alcohol use
- Certain medications (e.g., diuretics, laxatives, some chemotherapies)
How Can You Boost Magnesium Naturally?
If you're worried about your magnesium levels, there are several things you can do to improve magnesium absorption.
1. Eat Magnesium-Rich Foods
Dietary sources of magnesium include:
- Leafy greens (spinach, kale)
- Whole grains (brown rice, oats)
- Nuts and seeds (pumpkin, chia, almonds)
- Legumes (lentils, black beans)
2. Consider Supplements
Magnesium supplements come in many forms, such as oxide, citrate, and glycinate. Talk to a healthcare provider to determine which supplement and dosage is best for you.
3. Focus on a Balanced Diet
Other vitamins and minerals may also affect magnesium levels. Eating a nutritious, well-balanced diet can help your body absorb minerals better overall.
How Can You Balance Caffeine and Magnesium?
To enjoy your morning coffee without compromising magnesium:
- Cut back on caffeine or choose decaf. Decaf coffee still contains some caffeine, but not as much as regular coffee.
- Stay hydrated to offset caffeine’s dehydrating effects.
- Eat more magnesium-rich foods or talk to a medical provider about supplements.
