Nutrition Education and Racial Disparities in Health


Detox Blog Series Part 3 | The PRAL Formula

Key Topics: Digestive Health
March 29, 2018 • 1 min read

Why is PRAL important? Diet affects acid-base status, and a person’s acid load can be specifically manipulated by dietary means.

What is Potential Renal Acid Load?

Potential Renal Acid Load (PRAL) is a value calculated from a formula developed by Thomas Remer and other researchers at the Department of Nutrition and Health: The Research Institute of Child Nutrition, in Dortmund, Germany, to assess the acidity of foods and diets.

PRAL Formula

PRAL = 0.49 x protein (g) + 0.037 x phosphorus (mg) – 0.021 x potassium (mg) – 0.026 x magnesium (mg) – 0.013 x calcium (mg).1

Today, there is a general consensus that diet can markedly affect acid-base status and that a person’s acid load can be specifically manipulated by dietary means.

In general, protein and cereal grains are metabolized to acidic residues, while fruits and vegetables are metabolized to alkaline residues. Current American diets are progressively more acidic in comparison to pre-agricultural diets (mean Net Acid Load of -88mEq/d vs. +48mEq/d).2 With the decline in renal function that occurs with aging, older persons are not able to excrete excess hydrogen ions, and they develop mild, but slowly increasing metabolic acidosis.1

A study by  examined whether a plant-based dietary supplement, one marketed to increase alkalinity, impacts urinary pH.3 Using pH test strips, the urinary pH of 34 healthy men and women (33.9 +/- 1.57 y, 79.3 +/- 3.1 kg) was measured for seven days to establish a baseline urinary pH without supplementation. After this initial baseline period, urinary pH was measured for an additional 14 days while participants ingested the plant-based nutritional supplement. At the end of the investigation, pH values at baseline and during the treatment period were compared to determine the efficacy of the supplement. Mean urinary pH statistically increased (p = 0.03) with the plant-based dietary supplement. Mean urinary pH was 6.07 +/- 0.04 during the baseline period and increased to 6.21 +/- 0.03 during the first week of treatment, and to 6.27 +/- 0.06 during the second week of treatment.3

Conclusion: Supplementation with a plant-based dietary product for at least seven days increases urinary pH, potentially increasing the alkalinity of the body.3

Read part 4 of the Detox Blog Series.

Learn more.

Did you like this article?

  1. Remer, T., Dimitriou, T., Manz, F. (2003). Dietary potential renal acid load and renal net acid excretion in healthy, free-living children and adolescents. Am J Clin Nutr, 77 (5), 1255-60.
  2. Sebastian, A., Frassetto, L. A., Sellmeyer, D. E., Merriam, R. L., Morris, R. C. (2002). Estimation of the net acid load of the diet of ancestral preagricultural Homo sapiens and their hominid ancestors. Am J Clin Nutr, 76 (6), 1308-16
  3. Berardi, J. M., Logan, A. C., Rao, A. V. (2008). Plant based dietary supplement increases urinary pH. J Int Soc Sports Nutr, 5, 20.

Scientifically driven. Education focused. Healing Inspired.

Subscribe to Insights

Receive clinically driven nutrition insights you can trust.

Animated Newsletter WM

Join Our Community to Read Further

This is a premium article created for our Healthcare Practitioner readers. Create a free account to continue reading and gain full access.



WholisticMatters offers health care practitioners and nutrition enthusiasts alike the opportunity to create a free profile for access to site features like bookmarking. Enjoying an article you are reading or a video you are watching? Save it to come back to later! Sign up in seconds for continuous access to all that WholisticMatters has to offer.

WholisticMatters also offers health care practitioners who create a free user profile access to exclusive content and tools to utilize in clinical practice. Articles, tools, and downloads created specifically for practitioners to use in their office for better patient education in clinical nutrition and health. Sign up today with your email and credentials so we can confirm you as a health care practitioner, and you are free to peruse the resources unique to you and your colleagues in health.


Create Your Account:

show-pass Please use 8 or more characters with a mix of letters, numbers & symbols

Create a free account to use our great bookmarking tool

Once your account is created, you'll be able to save and organize what matters to you!

Already have an Account? Login Here

Click 'Sign Up' above to accept Wholistic Matters's Terms of Service & Privacy Policy.

Are you a Healthcare Professional? Sign Up For Free Access!

We'll verify your credentials and get you access to our great interactive tools.

Already have an Account? Login Here

Click 'Sign Up' above to accept Wholistic Matters's Terms of Service & Privacy Policy.