Do you recommend malic acid supplementation for patients with recurrent calcium oxalate nephrolithiasis and hypocitraturia?  

F. Malic acid, like citric acid, is metabolized as a protonated acid and used as a metabolite—it produces no alkali. Malate is metabolized as an acid and in doing so takes up a proton—just as citrate does—producing new bicarbonate, and so is an alkali.Rodgers et al., PMID 2405...