Baking Soda and Kidney Disease: Not Just for Baking and Cleaning (Part 1)

Baking soda. You know it for its use in baking, cleaning, and maybe even teeth whitening. Its formal chemical name is sodium bicarbonate, and it’s not just used for baking and cleaning anymore. Sodium bicarbonate, or baking soda, is also used in the treatment of kidney disease. The National Kidney Foundation’s Kidney Disease Outcomes Quality Initiative (KDOQI) recommends the use of sodium bicarbonate to treat metabolic acidosis. ¹ This condition occurs when there is an excessive buildup of acid in the blood.

Who Needs Sodium Bicarbonate?

If sodium bicarbonate is considered important for a person’s treatment, then their physician will prescribe a dose of sodium bicarbonate in a tablet form. It can help be a buffer to decrease acid level in the blood. Be aware this medication is high in sodium and should not be used without physician approval. Problems with metabolic acidosis are more likely present in late stages of chronic kidney disease (CKD) and in dialysis patients.

How Does Sodium Bicarbonate Work in the Body?

Our body systems function best in a narrow pH range, or measure of acidity vs. alkalinity (base). Our kidneys and lungs are the organs that work to maintain this proper acid-base balance. Healthy kidneys normally remove excess acid through urine and by making a base, bicarbonate. The bicarbonate neutralizes the acid to decrease the acid level. The lungs help to remove acid by increasing breathing rate to breathe out carbon dioxide. With kidney disease, the kidneys are not able to adequately perform their job. They can no longer maintain the proper acid-base balance in the body. As a result, an excess buildup of acid results in metabolic acidosis.

Sodium Bicarbonate and Chronic Kidney Disease

Metabolic acidosis has been associated with the progression of CKD.^2,3 Sodium bicarbonate supplementation is recommended for CKD patients whose bicarbonate lab levels are less than 22 mmol/L.^1,2 Sodium bicarbonate, a base, helps to neutralize and decrease the blood acid levels. Studies have been done to see if bicarbonate supplementation slows the progression of CKD.^2-4 A study published in 2010 compared sodium bicarbonate, sodium chloride, and placebo supplementation in stage 2 hypertension-associated CKD patients over 5 years.⁴ The decline in kidney function decreased significantly for those taking sodium bicarbonate compared to the other groups. This slowing of CKD progression with sodium bicarbonate supplementation was also supported by a 2015 review of other small studies that included participants with CKD stages 2-5.³ The results from these studies show that sodium bicarbonate may slow the progression of kidney disease.

Side Effects of Sodium Bicarbonate

Common side effects of sodium bicarbonate include belching and flatulence.² It is important to note that higher doses may cause fluid retention and worsen blood pressure control with CKD patients. Sodium bicarbonate may also reduce serum potassium. This can be beneficial for people with later stages of CKD who are at risk of high potassium levels.

Look for more information on metabolic acidosis and sodium bicarbonate, including diet’s role in acidosis in my next blog post coming in April.

There are 30 million adults with kidney disease in the U.S. Take the risk quiz to learn more about kidney disease risk factors.

References:

1. National Kidney Foundation: K/DOQI clinical practice guidelines for nutrition in chronic renal failure. American Journal of Kidney Diseases Volume 35, Issue 6, pS1-S140, 2000 (PDF version: http://www.kidney.org/sites/default/files/docs/kdoqi2000nutritiongl.pdf)
2. Bicarbonate Therapy for Prevention of Chronic Kidney Disease Progression. Igor Loniewski, Donald E. Wesson, Kidney International, Volume 85, p529-535, 2014
3. Current Status of Bicarbonate in CKD. Mirela Dobre, Mahboob Rahman, Thomas H. Hostetter, Journal of the American Society of Nephrology, Volume 26, p515-523, 2015
4. Daily Oral Sodium Bicarbonate Preserves Glomerular Filtration Rate by Slowing its Decline in Early Hypertensive Nephropathy. Ashutosh Mahajan, et al., Kidney International, Volume 78, p303-309, 2010
5. A Comparison of Treating Metabolic Acidosis in CKD Stage 4 Hypertensive Kidney Disease with Fruits and Vegetables or Sodium Bicarbonate. Nimrit Goraya, et al., Clinial Journal of the American Society of Nephrology, Volume 8, p371-381, 2013
6. Dietary Acid Reduction with Fruits and Vegetables or Bicarbonate Attenuates Kidney Injury in Patients with a Moderately Reduced Glomerular Filtration Rate Due to Hypertensive Nephropathy, Nimrit Goraya, et al., Kidney International, volume 81, p86-93, 2012

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This article is for informational purposes only and is not a substitute for medical advice or treatment. Consult your physician and dietitian regarding your specific diagnosis, treatment, diet and health questions.