# Citrate-based dietary alkali supplements available in Germany: an overview

## TL;DR

This paper compares citrate-based alkali supplements in Germany, focusing on their ability to reduce acid load in the diet and their mineral content.

## Contribution

The study provides a detailed comparative analysis of available alkali supplements in Germany, highlighting their PRAL-lowering potential and cost-effectiveness.

## Key findings

- Sixteen supplements were identified with varying alkali content and PRAL-lowering potential.
- The median TAL was 1220 mg, and PRAL reduction ranged from -51.65 to -8.32 mEq per recommended dose.
- Price differences were significant, with a median cost of 3.01 cents per 1 mEq PRAL reduction.

## Abstract

Fruits and vegetables are abundant in alkali precursors and effectively reduce the Potential Renal Acid Load (PRAL) from diet. Oral alkali supplements are supposed to exert comparable alkalizing effects on the human body, and have been shown to beneficially affect bone and kidney health. A comparative analysis of the available dietary alkali supplements in Germany was performed, contrasting their potential PRAL-lowering potential.

We reviewed the currently available dietary citrate-based alkali supplements sold in Germany with a special focus on their mineral content, their PRAL-lowering potential and other characteristics inherent to each product. Supplements containing either potassium-, calcium- or magnesium citrate or any combination of these organic salts were reviewed. The total alkali load (TAL) was calculated based on the recommended daily dosage (RDD).

Sixteen supplements with a mean alkali powder content of 220.69 ± 111.02 g were identified. The mean magnesium content per RDD was 239.93 ± 109.16 mg. The mean potassium and median calcium content were 550 ± 325.58 mg and 280 (240) mg, respectively. Median TAL was 1220 (328.75) mg. The PRAL-lowering potential from a single RDD ranged from − 51.65 mEq to -8.32 mEq. Substantial price differences were found, and the mean price of the examined supplements was 16.67 ± 5.77 Euros. The median price for a 1 mEq PRAL-reduction was 3.01 (3.14) cents, and ranged from 0.77 cents to 10.82 cents.

Noticeable differences between the identified alkali supplements were encountered, warranting an individual and context-specific approach in daily clinical practice.

The online version contains supplementary material available at 10.1186/s40780-024-00342-0.