Urinary oxalate excretion performs a crucial function in calcium oxalate stone formation. The vast majority of urinary oxalate is derived from endogenous synthesis and dietary sources. There was an ongoing debate concerning the affect of vitamin C supplementation on urinary oxalate excretion. The two articles mentioned right here pro-vide additional data on this topic.
Impact of Vitamin C Dietary supplements on Urinary Oxalate and pH in Calcium Stone-Forming Sufferers
Baxmann AC, De O G Mendonca C, Heilberg IP.
Kidney Int. 2003;63:1066–1071 [PubMed] [Google Scholar].
Grownup calcium oxalate stone-formers have been administered both 1 gram (group 1) or 2 grams (group 2) of vitamin C each day for 3 days whereas wholesome, non-stone-forming adults (group 3) got the 1-gram dose each day throughout the identical time. The members weren’t positioned on a metabolic weight loss plan, however have been instructed to chorus from consuming meals wealthy in vitamin C and oxalate, in addition to dairy merchandise. Twenty-four-hour urine collections have been obtained at baseline and after vitamin C administration.
Urinary pH didn’t change after vitamin C supplementation in any of the teams. Nevertheless, there have been statistically vital will increase in oxalate excretion in all 3 teams: 61% in group 1, 41% in group 2, and 56% in group 3. A major improve in calcium oxalate urinary supersaturation (by Tiselius index) occurred in all teams after supplemental vitamin C consumption.
Impact of Ascorbic Acid Consumption on Urinary Stone Threat Elements
Traxer O, Huet B, Poindexter J, et al.
J Urol. 2003;170:397–401 [PubMed] [Google Scholar].
On this double-blind, randomized, crossover examine, grownup calcium oxalate stone-formers and non-stone-forming adults have been positioned on a managed metabolic weight loss plan for two 6-day phases. Throughout one of many phases, they got 1 gram of vitamin C twice a day, and so they obtained a placebo throughout the different section. Twenty-four-hour urine specimens have been collected on days 5 and 6 of every section.
There have been no adjustments in urinary pH after vitamin C ingestion in both group, though there was a reasonable and statistically vital improve in urinary oxalate excretion in controls (20%) and stone-formers (33%).
Conclusions
Each of those articles clearly reveal that 1 to 2 grams of ascorbic acid administered each day to each regular topics and calcium oxalate stone-formers end in no urinary pH adjustments however in elevated oxalate excretion. Due to this fact, this apply shouldn’t be utilized in managing sufferers with struvite calculi, as a result of it doesn’t cut back urinary pH, or in calcium oxalate stone-formers, as it’d promote stone exercise.
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