ascorbic-acid and Nephrolithiasis

Cranberry supplements are commonly used as a natural deterrent to urinary tract infection. However, one small study (n = 5) which showed an increase in urinary oxalate levels following cranberry supplementation has led to its use with caution among patients susceptible to nephrolithiasis. Furthermore, most commonly available cranberry tablet preparations contain vitamin C, which has been independently shown to increase urinary oxalate excretion. The aim of this study is to investigate the influence of cranberry supplementation on urinary oxalate excretion.. Fifteen participants were randomised to receive cranberry tablets alone or cranberry tablets containing vitamin C. Tablets were taken at the manufacturers recommended dosage for a period of 14 days. Participants provided a 24 h urine collection at trial entry and day 14. Urinary variables were compared to assess for changes in oxalate levels.. The median age was 27 years (21-43). There was no difference in the 24 h urine volume pre or post commencement of cranberry tablets (1.7 vs 2 L, p = 0.07). An increase in median urinary oxalate excretion was observed in participants taking both cranberry-only tablets (0.10 mmol/day) and tablets containing vitamin C (1.15 mmol/day).. Dietary supplementation with cranberry increases urinary oxalate excretion and should be avoided in patients at risk of urolithiasis.

Topics: Adult; Ascorbic Acid; Dietary Supplements; Female; Humans; Male; Nephrolithiasis; Oxalates; Plant Preparations; Renal Elimination; Risk Factors; Vaccinium macrocarpon; Vitamins; Young Adult

Administration of natural antioxidants has been used to protect against nephrolithiasis. Urolithiasis was induced by ethylene glycol (EG) in Wistar rats. For 4 weeks, group 1 (control) was fed with a standard commercial diet. Group 2 received the same diet with 0.75% of EG. Group 3 received EG plus the diet and water added with antioxidant nutrients and lime juice as the dietary source of citrate (EG + AX). Group 4 same as group 3 with no EG in water. For 8 weeks, group 5 was fed the standard diet with EG in water for the first 28 days, followed by no EG. Group 6 received the diet with EG for the first 28 days, followed by discontinuation of EG and addition of antioxidant nutrients. Group 7 were provided the diet with antioxidant nutrients for 8 weeks. Group 8 received the diet with antioxidant nutrients for 4 weeks, followed by antioxidant nutrients with EG for the next 4 weeks. Blood samples were collected and kidneys were removed. The size and the mean number of crystal deposits in EG-treated groups was significantly higher than the EG-treated groups, added with antioxidant nutrients and lime juice. After 4 weeks, the mean concentration of malondialdehyde in group 2 was higher than the group 3, and significantly lower in group 4; and in groups 7 after 8 weeks, as well. After 8 weeks, supplementation developed less mean number of deposits in group 6 as compared to group 5; and in group 8, the crystal deposits was substantially less than either group 2 or group 5 (EG-treated rats). Elevated concentration of androgens (as promoters of the formation of renal calculi) as a result of EG consumption decreased following antioxidant supplementations. Results showed a beneficial effect of antioxidant and provided superior renal protection on treating and preventing stone deposition in the rat kidney.

Topics: Animals; Antioxidants; Ascorbic Acid; Boron; Dihydrotestosterone; Ethylene Glycol; Kidney; Malondialdehyde; Nephrolithiasis; Oxidative Stress; Rats, Wistar; Selenium; Sex Hormone-Binding Globulin; Testosterone; Treatment Outcome; Vitamin A; Vitamin B 6; Vitamin E; Vitamins; Zinc