The Citrate and Oxalate Association

Background: Higher urine oxalate excretion has been associated with higher urine citrate excretion. The mechanism for this association may be due to simultaneous dietary intake oxalate and citrate in food or transporter linkage of SLC26A6 and NaDC1 in the kidney. Methods: Twenty-six participants were admitted to the clinical research center and given sodium oxalate. Timed pre-sodium oxalate (3) and post-sodium oxalate (6) urine samples were collected every hour. Twenty participants also consumed a low oxalate, low citrate breakfast at the time of the sodium oxalate and 6 participants remained fasting for the duration of the protocol. Urinary excretions and fractional excretions of citrate and oxalate were calculated and plotted against each other. Results: Thirteen of the 26 participants were female with mean age 54 years. Higher urine oxalate excretion was correlated with higher urine citrate excretion both participants who consumed breakfast after sodium oxalate and for those who only consumed sodium oxalate (Figure 1A) and individuals appeared to cluster into their own ranges (Figure 1A). There was no correlation between fractional excretions of oxalate and citrate (Figure 2A) but there continued to be individual variability (Figure 2B). Conclusion: After consumption of sodium oxalate, urine oxalate and citrate excretions correlate but fractional excretions do not correlate. There may be individual variability to the urine citrate response to an oxalate load. Funding: NIDDK Support