Dietary Treatment of Metabolic Acidosis in Chronic Kidney Disease

Abstract

Chronic kidney disease and reduced glomerular filtration rate are risk factors for the development of chronic metabolic acidosis. The prevention or correction of chronic metabolic acidosis has been found to slow progression of chronic kidney disease. Dietary composition can strongly affect acid⁻base balance. Major determinants of net endogenous acid production are the generation of large amounts of hydrogen ions, mostly by animal-derived protein, which is counterbalanced by the metabolism of base-producing foods like fruits and vegetables. Alkali therapy of chronic metabolic acidosis can be achieved by providing an alkali-rich diet or oral administration of alkali salts. The primary goal of dietary treatment should be to increase the proportion of fruits and vegetables and to reduce the daily protein intake to 0.8⁻1.0 g per kg body weight. Diet modifications should begin early, i.e., even in patients with moderate kidney impairment, because usual dietary habits of many developed societies contribute an increased proportion of acid equivalents due to the high intake of protein from animal sources.

Keywords: alkali citrate; bicarbonate; fruits; kidney disease; metabolic acidosis; protein; urinary stones; urolithiasis; vegetables.

Figure 1

Diurnal variation in urinary pH during a 24-h period in healthy individuals under controlled, standardized conditions before (control, blue line) and after receiving 1500 mg/day l-methionine (red line) (M ± SEM) (* p < 0.05) [31].

Figure 2

Diurnal variation in urinary pH during a 24-h period in healthy individuals under controlled, standardized conditions before (control, blue line) and after receiving bicarbonate-rich mineral water (red line) (M ± SEM) (* p < 0.05) [36].