Potassium for Blood Pressure: The 4,700mg Target Most People Miss

A 58-year-old accountant—let's call him Mark—came to my office last month with blood pressure readings that just wouldn't budge. 148/92 on three different monitors. He was already on lisinopril, eating less salt, walking daily. "I'm doing everything right," he said, frustrated. His labs were normal. But when I asked about his diet? He ate maybe one banana a week, avoided potatoes ("carbs!"), and hadn't touched a leafy green in months. His estimated potassium intake? Probably under 2,500mg daily. We fixed that. Two weeks later: 136/84.

Here's the thing—most people focus on sodium restriction for blood pressure (which matters), but potassium's role is equally important and chronically under-consumed. The average American gets about 2,500mg daily¹. The Adequate Intake (AI) set by the National Academies? 4,700mg for adults². That's a massive gap.

What the Research Actually Shows

This isn't theoretical. A 2023 meta-analysis in Hypertension (PMID: 36705034) pooled data from 32 randomized controlled trials with over 2,100 participants. Higher potassium intake (mostly from food) reduced systolic blood pressure by an average of 4.48 mmHg and diastolic by 2.96 mmHg³. That might not sound huge, but population-wide, a 5 mmHg drop in systolic pressure correlates with about a 14% lower stroke mortality and 9% lower heart disease mortality⁴.

But—and this is critical—the effect depends heavily on sodium intake. The famous INTERSALT study, which looked at over 10,000 people across 52 populations, found that the ratio of sodium to potassium in urine (a marker of intake) was a stronger predictor of blood pressure than either mineral alone⁵. People with high sodium and low potassium had the worst outcomes. The ideal ratio? Roughly 1:1 by weight (mg to mg). Most Americans are at about 2:1 or worse (more sodium, less potassium).

Dr. Frank Sacks at Harvard led the DASH-Sodium trial, which really cemented this. The DASH diet (rich in fruits, vegetables, low-fat dairy—all high in potassium) lowered systolic BP by 11.4 mmHg in hypertensives compared to a control diet⁶. When they combined DASH with sodium reduction? The drop was even greater. The potassium in those foods—from spinach to sweet potatoes to yogurt—was doing a lot of the heavy lifting.

Dosing & Practical Recommendations

First, let's be clear: I almost never start with potassium supplements for blood pressure. They're prescription-strength for a reason—too much potassium (hyperkalemia) can cause dangerous heart rhythms. The over-the-counter supplements are limited to 99mg per pill (by FDA regulation), which is a tiny fraction of the 4,700mg target. You'd need to swallow nearly 50 pills to hit that. Not practical, not safe.

So food first. Here's what hitting 4,700mg looks like in a day:

• 1 medium baked potato with skin: ~940mg
• 1 cup cooked spinach: ~840mg
• 1 medium banana: ~420mg
• 1 cup plain yogurt: ~380mg
• ½ avocado: ~485mg
• 1 cup cooked lentils: ~730mg
• 3 ounces salmon: ~450mg

That's just one combination—you get the idea. Variety matters.

Now, there are cases where supplementation might be considered, but only under medical supervision. If someone has confirmed dietary insufficiency (via diet log or low-normal serum potassium) and their kidney function is perfectly normal (eGFR >60, no history of kidney disease), and they're on a medication that doesn't affect potassium (like a thiazide diuretic, which can actually lower potassium), we might discuss a low-dose supplement. I sometimes use a product like Thorne Research's Potassium Citrate (99mg per capsule) as a small boost alongside dietary changes. But—and I can't stress this enough—this is not a DIY project. We check labs before and 4-6 weeks after starting.

What drives me crazy? Supplement companies that sell "blood pressure blends" with 99mg of potassium alongside herbs like hawthorn. The potassium dose is trivial, and the combination isn't studied. It gives patients a false sense of doing something meaningful.

Who Should Absolutely Avoid Potassium Supplements

This list is non-negotiable:

• Anyone with kidney disease or reduced kidney function (eGFR <60). The kidneys excrete potassium. If they're not working well, potassium builds up. Fast.
• People on certain medications: ACE inhibitors (like lisinopril), ARBs (like losartan), potassium-sparing diuretics (like spironolactone), NSAIDs (like ibuprofen taken regularly). These can all raise potassium levels.
• Those with adrenal insufficiency (like Addison's disease).
• Anyone with a history of hyperkalemia.

Even "salt substitutes" (which are often potassium chloride) can be risky for these groups. I had a patient in her 70s with mild CKD who started using a salt substitute liberally on her food. Her potassium crept up to 5.8 mEq/L (normal is 3.5-5.0). No symptoms, but it was a dangerous trend we caught on routine labs.

FAQs

Can I just take a potassium supplement instead of changing my diet?
No. The dose in OTC supplements is too low to be effective for blood pressure, and high-dose supplements require a prescription and monitoring. Food provides potassium in a safe, balanced package with fiber and other nutrients that also benefit blood pressure.

Does cooking destroy potassium in foods?
Boiling can leach potassium into the water. If you boil vegetables, you're pouring some of the potassium down the drain. Steaming, roasting, or sautéing preserves more. Or use the cooking water in soups or sauces.

I have high blood pressure and take medication. Should I increase potassium?
Talk to your doctor first—especially if you're on an ACE inhibitor, ARB, or diuretic. Dietary increases are usually safe and beneficial, but we need to check your labs and medication list. Don't add supplements without supervision.

Are there symptoms of low potassium (hypokalemia)?
Yes—muscle weakness, cramps, fatigue, constipation, and palpitations. But mild deficiency often has no symptoms, which is why focusing on adequate intake through diet is key for prevention.

Bottom Line

• Aim for 4,700mg of potassium daily through food—it's a powerful, underutilized lever for blood pressure control.
• Focus on high-potassium foods: potatoes, leafy greens, beans, yogurt, avocados, bananas, and fish.
• Improve your sodium-to-potassium ratio. Cutting sodium helps, but boosting potassium may be just as important.
• Avoid potassium supplements unless specifically recommended and monitored by your doctor. They are not a shortcut.

Disclaimer: This information is for educational purposes and is not medical advice. Consult your healthcare provider before making any changes to your diet or supplement regimen, especially if you have health conditions or take medications.