When your kidneys start to fail, they don’t just stop filtering waste-they also lose their ability to keep your blood’s acid levels in check. This leads to metabolic acidosis, a hidden but dangerous condition that accelerates kidney damage, wastes muscle, and weakens bones. It’s not rare. In fact, nearly half of people with stage 5 chronic kidney disease (CKD) have it. And most don’t even know.
What Is Metabolic Acidosis in CKD?
Metabolic acidosis happens when your blood becomes too acidic because your kidneys can’t remove enough acid or make enough bicarbonate to balance it. Normal blood bicarbonate is 22-29 mEq/L. When it drops below 22, you’re in metabolic acidosis. In early CKD, your kidneys compensate. But by stage 3 or 4, that compensation starts to fail. By stage 5, acid builds up fast.This isn’t just a lab number. Left untreated, metabolic acidosis triggers a chain reaction: your body pulls calcium from bones to neutralize acid, leading to osteoporosis. It breaks down muscle, making you weaker and more prone to falls. It stresses your heart and raises your risk of hospitalization. And worst of all-it speeds up the decline of your kidney function.
Why Bicarbonate Is the First-Line Treatment
The most common fix is sodium bicarbonate. It’s cheap, available over the counter as baking soda, and prescribed in tablet form (650 mg = 7.6 mEq of bicarbonate). A major 3-year study in the Journal of the American Society of Nephrology found that CKD patients taking sodium bicarbonate slowed their eGFR decline by nearly 6 mL/min/1.73m² compared to those who didn’t. That’s the difference between reaching dialysis in 5 years versus 3.Doctors typically start with one tablet twice a day and adjust based on blood tests. The goal? Keep bicarbonate between 23 and 29 mEq/L, as recommended by KDIGO. But here’s the catch: sodium bicarbonate adds sodium. One 650 mg tablet has 305 mg of sodium. That’s 15% of your daily limit if you’re on a low-sodium diet. For someone with high blood pressure or heart failure, that’s risky.
Alternatives to Sodium Bicarbonate
Not everyone can tolerate sodium bicarbonate. That’s why alternatives exist.- Sodium citrate (Shohl’s solution): Less sodium than bicarbonate, but still contains sodium. Often used in liquid form, but tastes sour-many patients mix it with orange juice, adding sugar they shouldn’t have.
- Calcium citrate: Provides alkali without extra sodium. Each 500 mg tablet gives 120 mg of elemental calcium. Good for patients with heart issues, but too much can cause kidney stones or high calcium levels. Studies show a 27% higher risk of calcium stones with long-term use.
- Potassium citrate: Works well for acidosis and can help prevent kidney stones. But in CKD, potassium builds up easily. If your blood potassium is above 4.5 mEq/L, this can be dangerous. About 22% of CKD patients on potassium citrate develop dangerous hyperkalemia.
There’s also veverimer, a new drug designed to bind acid in the gut without affecting sodium or potassium. It showed promise in early trials, raising bicarbonate by 4.3 mEq/L in 12 weeks. But its phase 3 trial failed to prove it was better than placebo. The FDA didn’t approve it in 2023, and its maker is reanalyzing data for a 2024 resubmission.
Dietary Changes: The Power of Fruits and Vegetables
You don’t always need pills. Food can be medicine.Meat, cheese, and grains produce acid. Fruits and vegetables produce alkali. The Potential Renal Acid Load (PRAL) score measures this: beef has a PRAL of +9.5, cheddar cheese +8.0, but spinach is -2.8 and apples are -2.2.
A study from 2010 showed that increasing fruit and vegetable intake to 5-9 servings daily reduced acid load by 40-60 mEq/day-enough to raise bicarbonate by 1-3 mEq/L. One patient at Cleveland Clinic raised her bicarbonate by 3.5 mEq/L in six months just by swapping meat for beans, lentils, and leafy greens.
The problem? Adherence. Only 35% of CKD patients on dietary counseling hit a neutral PRAL score. It takes time, education, and support. Most need two or three sessions with a renal dietitian to learn what to eat and what to avoid.
Who Gets Treated-and Who Doesn’t
Despite strong guidelines, most people with metabolic acidosis go untreated. A 2023 analysis found only 43% of eligible CKD patients received alkali therapy. The gaps are stark: Black patients are treated 9% less often than White patients. Rural patients are 14% less likely to get care than urban ones.Why? Many doctors still think acidosis is “just a lab value.” Others worry about side effects. Some patients can’t afford pills. Others can’t swallow six tablets a day. One patient on Reddit said, “I take four sodium bicarbonate pills and two calcium citrate pills. I feel like I’m on a medication treadmill.”
And then there’s monitoring. Blood bicarbonate should be checked every 3-6 months in stable patients, and monthly when starting treatment. But many clinics don’t track it regularly. Without testing, you can’t treat.
The Controversy: What’s the Right Target?
There’s no one-size-fits-all target. KDIGO says 23-29 mEq/L. But new data suggests it’s more nuanced.A 2020 study found a U-shaped curve: the lowest death risk was at 24-26 mEq/L. Below 22, risk went up. Above 26, risk also went up-especially in older patients with heart disease. That’s why the 2024 KDIGO draft update proposes widening the target to 22-29 mEq/L, recognizing that even 22 is protective.
Now doctors are personalizing: 24-26 mEq/L for heart failure patients, 22-24 mEq/L for frail elderly patients with low body weight. It’s not about pushing bicarbonate as high as possible. It’s about finding the sweet spot that protects your kidneys without harming your heart or bones.
What’s Coming Next
The COMET-CKD trial, enrolling 1,200 patients, is testing high-dose vs. low-dose sodium bicarbonate. Results come in late 2025. Meanwhile, a new citrate-free alkali supplement called TRC001 is showing up in early trials with fewer stomach side effects than traditional options.The big picture? Correcting metabolic acidosis could prevent 28,000 cases of kidney failure each year in the U.S. and save $1.4 billion. But that won’t happen unless we start testing, treating, and educating patients early.
Metabolic acidosis isn’t a side effect of CKD-it’s a driver. And treating it isn’t optional. It’s part of the job.
Can baking soda really help with kidney disease?
Yes, but not as a DIY fix. Baking soda (sodium bicarbonate) is the same compound used in medical treatment. One teaspoon contains about 50 mEq of bicarbonate-far more than a single tablet. Taking it without medical supervision can cause dangerous sodium overload, especially if you have high blood pressure or heart failure. Always work with your nephrologist to determine the right dose and form.
How do I know if I have metabolic acidosis?
You won’t feel it at first. Early symptoms are vague-fatigue, weakness, or trouble breathing. The only reliable way to know is a blood test that checks serum bicarbonate. If you have CKD, ask your doctor to test your bicarbonate level at least once a year. If it’s below 22 mEq/L, treatment should be considered.
Is potassium citrate safe for CKD patients?
Generally, no. Potassium citrate can raise blood potassium levels, which is dangerous in CKD. About 18% of CKD patients on potassium supplements develop hyperkalemia. It’s only used if you’re low in potassium and have no other options. Most nephrologists avoid it in stages 3b-5 unless absolutely necessary.
Can diet alone fix metabolic acidosis in CKD?
Diet can help, but it’s rarely enough on its own. Eating more fruits and vegetables can lower acid load and raise bicarbonate by 1-3 mEq/L. But if your kidneys are severely damaged, you’ll likely still need alkali therapy. The best approach combines diet with medication-especially if your bicarbonate is below 20 mEq/L.
Why aren’t more doctors treating metabolic acidosis?
Many still don’t recognize it as a treatable condition. Some think it’s too minor. Others worry about side effects or lack time to educate patients. There’s also no FDA-approved branded drug for this use-just generics-so there’s little industry push. But guidelines are clear: treat it when bicarbonate drops below 22 mEq/L. It’s not optional.
What’s the best way to take sodium bicarbonate?
Start low: one 650 mg tablet once or twice daily with meals. Take it with plenty of water. Don’t crush or chew tablets unless instructed. If you get bloating or nausea, ask about switching to calcium citrate. Monitor your blood pressure and weight weekly. If you gain more than 2 pounds in a week or your blood pressure spikes, contact your doctor immediately.
Let me tell you-this is the most under-discussed issue in nephrology, and I’ve been pushing this for years. Metabolic acidosis isn’t just a lab anomaly-it’s a silent killer. I’ve seen patients with eGFR 20 who looked fine until their bicarbonate dropped to 18-and then, bam, muscle wasting, fractures, hospitalizations. Sodium bicarbonate? It’s not magic, but it’s the cheapest, most effective tool we’ve got. Don’t let the sodium scare you-monitor BP, adjust dose, and pair it with diet. That’s medicine, not guesswork.
Wow. Another feel-good article that ignores the real problem: healthcare inequality. You mention Black and rural patients get treated less-but you don’t say why. It’s because nephrologists are concentrated in cities, insurance denies coverage for bicarbonate unless you’re on dialysis, and primary care docs don’t even know what PRAL means. And now you want us to eat 9 servings of spinach? Good luck when your food desert only has canned corn and processed chicken. This isn’t a medical issue-it’s a systemic failure wrapped in jargon.
Hey, I just want to say-this was actually really helpful. I’ve been on bicarbonate for 18 months now, and my numbers are stable. I know some people say it’s just ‘baking soda,’ but it’s not that simple. I used to take it straight from the box-bad idea. I got bloated, my BP spiked. Now I take it with meals, drink water, and track my weight daily. It’s not glamorous, but it works. And honestly? I feel less tired. I’m not saying it’s perfect-but it’s better than doing nothing.
Let’s be clear: the KDIGO guidelines are outdated. The 2024 draft is a step forward, but still too vague. You cite a U-shaped curve, but fail to mention that the increased mortality above 26 mEq/L is primarily in patients with ejection fraction <35%. That’s critical. Also, the claim that diet alone can raise bicarbonate by 3 mEq/L? That’s from a 2010 study with n=42. No control group. No long-term follow-up. This isn’t evidence-it’s optimism dressed as science.
Stop pretending this is complicated. Bicarbonate below 22? Treat it. Full stop. No ‘maybe,’ no ‘depends.’ It’s not optional. If your doctor isn’t doing it, get a new one. Diet helps. Pills work. Sodium? Manage it. Potassium? Avoid it. End of story.
I’ve been a CKD patient for 11 years, and I’ve tried everything-bicarbonate, citrate, even the experimental stuff. What no one talks about is the mental toll. Taking 6 pills a day, every day, for years-it feels like your body is turning against you. I don’t want to be ‘on a medication treadmill.’ But I also don’t want dialysis at 52. So I do it. And I thank the people who write articles like this-because they remind me I’m not alone. Keep sharing. Even when it’s hard.
just read this and cried a little. my mom’s on bicarb and she hates it. says it tastes like chalk and makes her burp all day. but she takes it because she doesn’t want to be on dialysis. i wish there was a better way. maybe the new citrate-free thing will help? i hope so.
Oh please. Another ‘food is medicine’ fairy tale. You think telling someone with stage 4 CKD to eat ‘5-9 servings of spinach’ is realistic? That’s the kind of advice that comes from people who’ve never had to cook for themselves on a fixed income while managing 12 medications. And veverimer failed? Of course it did-Big Pharma doesn’t want a cheap, generic solution that doesn’t require lifetime prescriptions. This isn’t science. It’s corporate propaganda wrapped in clinical jargon.
the 2023 study showing 43% treatment rate? that’s not surprising. most docs dont even check bicarb. my nephro just says ‘you’re fine’ and moves on. i had to beg for the test. and now i’m on bicarb but my bp is up. so i stopped. guess i’ll just wait for dialysis. thanks for the info tho.