Serum creatinine, urine oxalate:creatinine ratio, and creatinine clearance vs. clinical timeline. (a) The chart shows the trend of serum creatinine (gray bars, with the values shown on the left axis), starting from a baseline of 1.2 mg/dL just over 4 months ago, gradually increasing up to 3.1 mg/dL 8 days ago, and rapidly increasing to 8.4 mg/dL on admission (day 0). The urine oxalate:creatinine ratio (red squares connected by lines, with values shown on the right axis) clearly shows hyperoxaluria at admission (0.084 at day 1, compared to a normal of 0.035). Vitamin C was stopped on day 4, and creatinine started improving after 2 days. (b) Renal function in terms of creatinine clearance (% of normal) is also shown.