Q: Given a passage, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.
Vitamin C can be metabolized to oxalate. Case reports have suggested an association between IV vitamin C and urinary oxalate excretion. Recently, the US Food and Drug Administration required the dose of vitamin C in IV multivitamin preparations to be increased from 100 mg to 200 mg/d. We compared the urinary oxalate excretion level in stable home total parenteral nutrition (TPN) patients receiving both doses of vitamin C.', 'Each participant provided a 24-hour urine sample for oxalate determination on the vitamin C dose (100 mg/d), and again after at least 1 month on the increased vitamin C dose (200 mg/d). A 2-day diet diary was completed covering the day before and the day of the urine collection and was analyzed for oxalate and vitamin C content. Comparisons were made using Student paired t test and Wilcoxon signed rank.', 'Thirteen patients (7 males/6 females) aged 63.1 +/- 12.2 years who had no history of nephrolithiasis and had received TPN for 55.9 +/- 78.8 months were enrolled. The most common indication for TPN was short bowel syndrome (38.5%). Eight patients had an intact colon. Urinary oxalate excretion increased on the 200-mg vitamin C dose, from 0.34 +/- 0.13 to 0.44 +/- 0.17 mmol/d (mean increase = 0.10 mmol/d; p = .04; 95% confidence interval 0.004 to 0.19 mmol/d). Oral intake of vitamin C and oxalate did not differ between the 2 collection periods.
A:
Does urinary oxalate excretion increase in home parenteral nutrition patients on a higher intravenous ascorbic acid dose?