Editing Chemistry of ascorbic acid (section)

====Conversion to oxalate====
In 1958, it was discovered that ascorbic acid can be converted to [[oxalate]], a key component of calcium oxalate [[kidney stone]]s.<ref name="pmid13525409">{{cite journal |vauthors=Hellman L, Burns JJ |title=Metabolism of L-ascorbic acid-1-C14 in man |journal=The Journal of Biological Chemistry |volume=230 |issue=2 |pages=923–30 |date=February 1958 |doi=10.1016/S0021-9258(18)70515-2 |doi-access=free |pmid=13525409 |url=https://www.jbc.org/article/S0021-9258(18)70515-2/pdf}}</ref><ref name="pmid27002809">{{cite journal |vauthors=Knight J, Madduma-Liyanage K, Mobley JA, Assimos DG, Holmes RP |title=Ascorbic acid intake and oxalate synthesis |journal=Urolithiasis |volume=44 |issue=4 |pages=289–97 |date=August 2016 |pmid=27002809 |pmc=4946963 |doi=10.1007/s00240-016-0868-7}}</ref><ref name="Kayis 2024">{{cite book |vauthors=Kayis C |title=Ascorbic Acid - Biochemistry and Functions |chapter=Effect of Ascorbic Acid on the Kidneys |publisher=IntechOpen |year=2024 |isbn=978-1-83768-562-2 |doi=10.5772/intechopen.111913 |doi-access=free |url=https://www.intechopen.com/citation-pdf-url/87322 |access-date=12 January 2025 |page=}}</ref> The process begins with the formation of [[dehydroascorbic acid]] (DHA) from the ascorbyl radical. While DHA can be recycled back to ascorbic acid, a portion irreversibly degrades to 2,3-diketogulonic acid (DKG), which then breaks down to both oxalate and the sugars [[erythrulose|L-erythrulose]] and [[threosone]].<ref name="pmid27002809"/><ref name="Kayis 2024"/><ref name="pmid38089442">{{cite journal |vauthors=Bao D, Wang Y, Zhao MH |title=Oxalate Nephropathy and the Mechanism of Oxalate-Induced Kidney Injury |journal=Kidney Diseases |volume=9 |issue=6 |pages=459–468 |date=December 2023 |pmid=38089442 |pmc=10712969 |doi=10.1159/000533295}}</ref> Research conducted in the 1960s suggested ascorbic acid could substantially contribute to urinary oxalate content (possibly over 40%), but these estimates have been questioned due to methodological limitations.<ref name="pmid27002809"/><ref name="Kayis 2024"/><ref name="pmid14217884">{{cite journal |vauthors=Atkins GL, Dean BM, Griffin WJ, Watts RW |title=Quantitative Aspects Of Ascorbic Acid Metabolism In Man |journal=The Journal of Biological Chemistry |volume=239 |issue= 9|pages=2975–80 |date=September 1964 |doi=10.1016/S0021-9258(18)93840-8 |doi-access=free |pmid=14217884 |url=https://www.jbc.org/article/S0021-9258(18)93840-8/pdf}}</ref> Subsequent large cohort studies have yielded conflicting results regarding the link between vitamin C intake and kidney stone formation. The overall clinical significance of ascorbic acid consumption to kidney stone risk, however, remains inconclusive, although several studies have suggested a potential association, especially with high-dose supplementation in men.<ref name="pmid27002809"/><ref name="Kayis 2024"/><ref name="pmid36839235">{{cite journal |vauthors=Cupisti A, Giannese D, D'Alessandro C, Benedetti A, Panichi V, Alfieri C, Castellano G, Messa P |title=Kidney Stone Prevention: Is There a Role for Complementary and Alternative Medicine? |journal=Nutrients |volume=15 |issue=4 |date=February 2023 |page=877 |pmid=36839235 |pmc=9959749 |doi=10.3390/nu15040877|doi-access=free }}</ref><ref name="pmid30178451">{{cite journal |vauthors=Jiang K, Tang K, Liu H, Xu H, Ye Z, Chen Z |title=Ascorbic Acid Supplements and Kidney Stones Incidence Among Men and Women: A systematic review and meta-analysis |journal=Urology Journal |volume=16 |issue=2 |pages=115–120 |date=May 2019 |pmid=30178451 |doi=10.22037/uj.v0i0.4275}}</ref>