Editing Stones: Evaluation and Medical Management (section)

=== Increase fluid intake ===
#'''<span style="color:#ff0000">Fluid intake that will achieve a urine volume of > 2.5 liters daily is recommended in all stone formers</span>'''
#*An RCT of recurrent calcium oxalate stone formers randomized to a high fluid intake vs. no specific recommendations found significantly reduced stone recurrence rates in the high fluid intake group (12% vs. 27%, respectively, at 5 years)
#*Although there is no definitive threshold for urine volume and increased risk, an accepted goal is ≥2.5 liters of urine daily.#**Because of insensible losses and varying intake of fluid contained in food, a universal recommendation for total fluid intake is not appropriate
#*'''Overall, most evidence suggests that it is not the type of fluid ingested that is important for stone prevention but rather the absolute amount of fluid volume taken in per day'''
#** Water hardness should be a minor concern with respect to stone formation
#** Carbonated water may provide some protective benefit
#** Citrus juices (particularly lemon and orange juices) may be a useful adjunct to stone prevention
#**'''Alcoholic beverages, coffee, decaffeinated coffee, tea and wine have been shown to be associated with a lower risk of stone formation'''
#**'''Sugar-sweetened beverages demonstrated an increased risk.'''
#***'''The only specific beverage that has been evaluated for an effect on stone recurrence in an RCT is soft drinks; the group avoiding soft drinks demonstrated a marginally lower rate of stone recurrence at the end of the 3-year trial but the effect appeared to be limited to those consuming primarily phosphoric acid-based (e.g. colas) rather than citric acid-based soft drinks'''
#***'''Soda flavored with phosphoric acid may increase stone risk, whereas those with citric acid may decrease risk'''
#**** Several sodas are acidified by citric acid and contain an amount of citrate equal to or greater than that of lemonade, including Diet Sunkist Orange, Diet 7Up, Sprite Zero, Diet Canada Dry Ginger Ale, Sierra Mist Free, Diet Orange Crush, Fresca, and Diet Mountain Dew. All of the aforementioned sodas have the potential to decrease the risk of kidney stones similar to or greater than lemonade.
#**** In contrast, colas, including Caffeine Free Diet Coke, Diet Coke, Diet Coke with Lime, Coke Zero, Caffeine Free Diet Pepsi and Pepsi, are acidified by phosphoric acid, not by citric acid and contain low citrate levels.
#***** One randomized study of recurrent stone formers with baseline soda consumption > 160 ml per day, found that over a 3-year period those who abstained from any soft drink consumption had a lower risk of symptomatic stone events (34%) compared to those who continued to drink sodas acidified by phosphoric acid (41%; RR, 0.83).§
#***'''Performance sports drinks'''
#**** '''May increase urinary citrate and pH''' thereby reducing risk of stones.
#***** However, these drinks have a high fructose and total carbohydrate content so they should not be recommended as the primary means of hydration for stone formers.
#**** Do not lead to hypernatriuria, even though sodium content may be high
#**** No effect on urinary calcium, oxalate, and uric acid.