Effect of Ascorbic Acid Consumption On Urinary Stone Risk Factors

Traxer, Olivier; Huet, B.; Poindexter, John R.; Pak, Charles Y.C.; Pearle, Margaret S.

doi:10.1097/01.ju.0000076001.21606.53

Cited by 152 publications

(96 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Another metabolic trial demonstrated that 1000 mg of supplemental vitamin C consumed twice daily increased urinary oxalate excretion by 20 to 33%. 23 To our knowledge, only two previous studies that used direct analytical techniques to measure food oxalate attempted to quantify the oxalate content of the typical Western diet. One study consisted of five healthy individuals (mean age 29 yr), and the mean oxalate intake, as measured by a 3-d dietary record, was 152 mg/d.…”

Section: Discussionmentioning

confidence: 99%

Oxalate Intake and the Risk for Nephrolithiasis

Taylor

Curhan

2007

Journal of the American Society of Nephrology

177

116

View full text Add to dashboard Cite

Most kidney stones consist of calcium oxalate, and higher urinary oxalate increases the risk for calcium oxalate nephrolithiasis. However, the relation between dietary oxalate and stone risk is unclear. This study prospectively examined the relation between oxalate intake and incident nephrolithiasis in the Health Professionals Follow-up Study (n ϭ 45,985 men), the Nurses' Health Study I (n ϭ 92,872 older women), and the Nurses' Health Study II (n ϭ 101,824 younger women). Food frequency questionnaires were used to assess oxalate intake every 4 yr. Cox proportional hazards regression was used to adjust for age, body mass index, thiazide use, and dietary factors. A total of 4605 incident kidney stones were documented over a combined 44 yr of follow-up. Mean oxalate intakes were 214 mg/d in men, 185 mg/d in older women, and 183 mg/d in younger women and were similar in stone formers and non-stone formers. Spinach accounted for Ͼ40% of oxalate intake. For participants in the highest compared with lowest quintile of dietary oxalate, the relative risks for stones were 1.22 (95% confidence interval [CI] 1.03 to 1.45; P ϭ 0.01 for trend) for men and 1.21 (95% CI 1.01 to 1.44; P ϭ 0.05 for trend) for older women. Risk was higher in men with lower dietary calcium (P ϭ 0.08 for interaction). The relative risks for participants who ate eight or more servings of spinach per month compared with fewer than 1 serving per month were 1.30 (95% CI 1.08 to 1.58) for men and 1.34 (95% CI 1.10 to 1.64) for older women. Oxalate intake and spinach were not associated with risk in younger women. These data do not implicate dietary oxalate as a major risk factor for nephrolithiasis. Kidney stones are common, costly, and painful. The lifetime prevalence of symptomatic nephrolithiasis is approximately 10% in men and 5% in women, 1,2 and more than $2 billion is spent on treatment each year. 3,4 Approximately 80% of kidney stones contain calcium, and the majority of calcium stones consist primarily of calcium oxalate. 5 Small increases in urinary oxalate can have a major effect on calcium oxalate crystal formation, 6 and higher levels of urinary oxalate are a major risk factor for the formation of calcium oxalate kidney stones. 5,7 Because oxalate is a metabolic end product and is excreted unchanged in the urine after absorption in the gastrointestinal tract, clinicians routinely recommend a low-oxalate diet to patients with calcium oxalate nephrolithiasis. 8 However, the role of dietary oxalate in the pathogenesis of calcium oxalate nephrolithiasis is unclear. 9 Uncertainty about the impact of dietary oxalate on stone risk centers around the contribution of oxalate intake to urinary oxalate excretion. A large amount of urinary oxalate is derived from the endogenous metabolism of glycine, glycolate, hydroxyproline, and dietary vitamin C, 10,11 and the proportion of urinary oxalate derived from dietary oxalate is unclear (estimates range from 10 to 50% 12 ). Studies of dietary oxalate and stone risk also must account for the intake...

show abstract

Section: Discussionmentioning

confidence: 99%

Oxalate Intake and the Risk for Nephrolithiasis

Taylor

Curhan

2007

Journal of the American Society of Nephrology

177

116

View full text Add to dashboard Cite

show abstract

“…[42][43][44] Patients and physicians have expected to overcome chronic disease such as cardiovascular disease or cancer by consumption of vitamin C, based on its antioxidant activities. 45 Previous studies were not able to show any benefit regarding the consumption of vitamin C and cancer prevention, urinary stone production 47 and reduction of common cold incidence. [48][49][50] Lee et al assessed the association between intake of vitamin C and mortality from cardiovascular disease in 1923 diabetic postmenopausal women.…”

Section: Vitamin Cmentioning

confidence: 99%

Vitamins, Are They Safe?

Hamishehkar¹,

Ranjdoost²,

Asgharian³

et al. 2016

Adv Pharm Bull

View full text Add to dashboard Cite

“…The results of many feeding studies may have limited applicability to free-living populations. For example, although 1000 mg of supplemental vitamin C consumed twice daily increases urinary oxalate excretion by 22% (11), the effect of lower, more commonly consumed doses of vitamin C on urinary oxalate excretion is uncertain. Previous population-based studies have been relatively small and provide conflicting results about the associations between vitamin C intake, body size, and urinary oxalate (12,13).…”

mentioning

confidence: 99%

Determinants of 24-hour Urinary Oxalate Excretion

Taylor¹,

Curhan²

2008

Clinical Journal of the American Society of Nephrology

150

View full text Add to dashboard Cite

Background and objectives: Higher levels of urinary oxalate substantially increase the risk of calcium oxalate kidney stones. However, the determinants of urinary oxalate excretion are unclear. The objective was to examine the impact of dietary factors, age, body size, diabetes, and urinary factors on 24-h urinary oxalate.Design, setting, participants, and measurements: We conducted a cross-sectional study of 3348 stone forming and nonstone-forming participants in the Health Professionals Follow-up Study (men), the Nurses' Health Study (older women), and the Nurses' Health Study II (younger women).Results: Median urinary oxalate was 39 mg/d in men, 27 mg/d in older women, and 26 mg/d in younger women. Participants in the highest quartile of dietary oxalate excreted 1.7 mg/d more urinary oxalate than participants in the lowest quartile (P trend 0.001). The relation between dietary and urinary oxalate was similar in individuals with and without nephrolithiasis. Participants consuming 1000 mg/d or more of vitamin C excreted 6.8 mg/d more urinary oxalate than participants consuming <90 mg/d (P trend < 0.001). Body mass index, total fructose intake, and 24-h urinary potassium, magnesium, and phosphorus levels also were positively associated with urinary oxalate. Calcium intake and age were inversely associated with urinary oxalate. After adjustment for body size, participants with diabetes excreted 2.0 mg/d more urinary oxalate than those without diabetes (P < 0.01).Conclusions: The impact of dietary oxalate on urinary oxalate appears to be small. Further investigation of factors influencing urinary oxalate may lead to new approaches to prevent calcium kidney stones.

show abstract

Effect of Ascorbic Acid Consumption On Urinary Stone Risk Factors

Cited by 152 publications

References 20 publications

Oxalate Intake and the Risk for Nephrolithiasis

Oxalate Intake and the Risk for Nephrolithiasis

Vitamins, Are They Safe?

Determinants of 24-hour Urinary Oxalate Excretion

Contact Info

Product

Resources

About