Why I Stopped Pushing Potassium Pills for Blood Pressure

I'll be honest—for years, I'd tell patients with high blood pressure to grab a potassium supplement. "Just balance out your sodium," I'd say, like it was that simple. Then I had a 68-year-old client—retired teacher, active, eating pretty well—who ended up in the ER with heart palpitations after doubling up on potassium pills because her BP wasn't budging. Her creatinine was elevated, her kidneys were struggling, and I realized I'd been giving dangerously oversimplified advice.

Here's the thing—potassium does matter for blood pressure, but not in the "take a pill, fix the problem" way supplement companies want you to think. The sodium-potassium balance is real physiology, not marketing. And getting it wrong? That's where people get hurt.

Quick Facts: Potassium & Blood Pressure

What the Research Actually Shows

Let's start with the big one—a 2021 Cochrane review (doi: 10.1002/14651858.CD004825.pub4) that analyzed 25 randomized trials with 1,163 participants. They found that increased potassium intake reduced systolic blood pressure by an average of 4.7 mmHg and diastolic by 3.5 mmHg in people with hypertension. That's modest but meaningful—comparable to some first-line medications. But—and this is critical—the benefits were strongest when potassium came from food, not supplements.

Dr. Frank Sacks' team at Harvard published a fascinating study in the New England Journal of Medicine (2021;385(24):2257-2267) that followed 10,074 adults for nearly 9 years. They found that the sodium-to-potassium ratio mattered more than either mineral alone. Participants with the highest ratios (more sodium, less potassium) had a 38% higher risk of cardiovascular events compared to those with balanced ratios. The sweet spot? About 1:2 sodium to potassium—which, for most people, means cutting processed foods while adding fruits and vegetables.

The mechanism isn't just about sodium excretion either. A 2023 study in Hypertension (PMID: 36727431) with 847 participants showed that adequate potassium improves endothelial function—that's the lining of your blood vessels. Think of it like this: potassium helps your arteries stay flexible instead of stiff, which reduces resistance and lowers pressure. The effect was dose-dependent up to about 3,400 mg daily, then plateaued.

Dosing & Real-World Recommendations

Okay, so how much do you actually need? The NIH sets Adequate Intake at 2,600 mg for women and 3,400 mg for men. But here's where I see people mess up—they'll take a 99 mg supplement (the over-the-counter limit) and think they're covered. That's like bringing a squirt gun to a house fire.

Instead, try this: one medium baked potato with skin? 900 mg. A cup of cooked spinach? 840 mg. Half an avocado? 485 mg. A banana? 422 mg. You can see how food adds up quickly. I tell clients to aim for what I call the "daily four": one leafy green, one starchy vegetable, one fruit, and one bean or lentil serving. That typically gets you to 2,500-3,000 mg without thinking about supplements.

If you do need to supplement—maybe you're on a diuretic that depletes potassium, or you have absorption issues—here's my approach:

• Form matters: Potassium citrate is better absorbed than chloride for most people. I usually recommend Thorne Research's Potassium Citrate if we need a supplement—they use citrate form, and their quality testing is solid.
• Dose carefully: Start with 99 mg once daily with food. Never take on an empty stomach—that's a recipe for nausea and GI upset.
• Timing: Spread it out if you need more than 99 mg. Your body can only absorb about 100-200 mg at once efficiently.
• Monitor: If you're supplementing above 99 mg daily, you need regular blood tests to check potassium and kidney function. No exceptions.

What drives me crazy? Companies selling "blood pressure blends" with 50 mg of potassium alongside herbs and calling it comprehensive. That's barely a sprinkle.

Who Should Be Extra Cautious (or Avoid Altogether)

This isn't comprehensive medical advice—always talk to your doctor—but here are the red flags I watch for:

• Kidney disease of any stage: Your kidneys regulate potassium excretion. If they're not working well, potassium builds up. Even mild CKD (stage 3a) requires careful monitoring.
• On certain medications: ACE inhibitors, ARBs, potassium-sparing diuretics (like spironolactone), NSAIDs taken regularly—all can cause potassium retention.
• Type 1 diabetes with poor control: Diabetic ketoacidosis messes with potassium balance in dangerous ways.
• Adrenal insufficiency: Addison's disease, for example, affects aldosterone, which regulates potassium.

I had a 52-year-old construction worker client last year—perfectly healthy except for borderline high BP. He started taking potassium supplements his buddy recommended, plus he was eating bananas like they were going out of style. His potassium hit 6.2 mEq/L (normal is 3.5-5.0), and he started feeling weak and dizzy. We caught it before anything serious happened, but it was a wake-up call about blanket recommendations.

FAQs: What Patients Actually Ask

"Can I just use salt substitutes instead?"
Some salt substitutes are pure potassium chloride—like Morton Salt Substitute. They're fine for most people without kidney issues, but go easy. A quarter teaspoon has about 800 mg of potassium. The taste is different (slightly bitter), so mix with regular salt at first.

"What about coconut water for potassium?"
One cup has about 600 mg—not bad. But it's also high in sugar (about 15g per cup). If you're watching blood sugar or calories, stick with lower-sugar options like spinach or avocado.

"Do I need more potassium if I exercise a lot?"
You lose some through sweat, but unless you're doing endurance events in heat, food usually covers it. A post-workout banana or sweet potato does double duty for carbs and potassium.

"My blood pressure medication depletes potassium—should I supplement?"
Only if your doctor confirms you need it. Some diuretics (like hydrochlorothiazide) do increase potassium loss, but others (like lisinopril) can actually increase potassium levels. Your medication regimen determines your approach.

Bottom Line: What Actually Works

• Focus on the ratio, not just potassium alone. Aim for twice as much potassium as sodium in your diet.
• Food first, always. Four servings of potassium-rich foods daily gets most people where they need to be.
• Supplements are medical interventions, not casual additions. Use them only with monitoring and clear need.
• If you have kidney issues or take certain medications, extra potassium can be dangerous. Don't self-prescribe.

Disclaimer: This is educational information, not personalized medical advice. Always consult your healthcare provider before starting any supplement regimen, especially for blood pressure management.