This section is from the book "Practical Dietetics With Special Reference To Diet In Disease", by William Gilman Thompson. Also available from Amazon: Practical Dietetics with Special Reference to Diet in Disease.
The condition of oxaluria may be unsuspected by the patient, or it may attract his attention by a sensation of burning in the urethra, desire for frequent micturition, headache, "nervousness," etc.
The occasional presence of a trace of calcium oxalate in the urine need not be considered as abnormal, but the continued presence of this substance in excess is mainly caused by eating certain kinds of food and by dyspepsia and perverted nutrition, involving incomplete oxidation in the system of starchy, saccharine, and fatty foods.
Ellis says that "oxalic acid is very readily prepared in the chemical laboratory by the action of reagents upon sugar, starch, and cellulose. This fact would seem to render probable the possibility of its formation from the imperfect oxidation of these substances in the body," especially from bacterial fermentation in the alimentary canal.
Flugge has shown that bacteria can form this acid, and its crystals occur in the intestine and are often found in the faeces. Oxaluria is common in connection with dyspepsia, and it is not altogether improbable that some of it may be derived from imperfect digestion of food in the intestine, and be absorbed into the blood just as ptomaines are.
Cantani finds that oxaluria is frequently present among those who indulge too freely in saccharine and amylaceous foods. Beneke holds quite an opposite theory, and attributes the condition to imperfect metabolism of proteid foods. Even fasting animals may still show traces of calcic oxalate in their urine, and both increased and diminished oxidation have been held accountable for oxaluria.
Vegetables and fruits containing oxalic acid and its salts, and which may cause oxaluria when eaten in excess, are rhubarb, tomatoes, turnips, onions, sorrel, spinach, figs, strawberries, apples, pears. Many other fruits and vegetables contain traces of oxalic acid, but this fact is of little or no dietetic importance. Raw fruits and vegetables which contain citric, malic, and other organic acids seem to bear close relation to the formation of oxalic acid. The latter is not necessarily ingested with the food, but is produced in the body from a variety of substances.
The diet should consist of animal food - fish, poultry, game, and meat - with stale bread or toast with a minimum of butter. Tea, coffee, carbonic-acid water, and alcohol should be temporarily forbidden. Hot water (three quarters of a pint) should be sipped half an hour before each meal, and before breakfast a drachm or more of Carlsbad salts may be taken in constipated cases. Dilute mineral acids, hydrochloric or nitro-hydro-chloric, are beneficial if taken immediately after meals in doses of fifteen or twenty minims in water.