Effects of Magnesium Oxide on the Crystallization of Calcium Salts in Urine in Patients with Recurrent Nephrolithiasis

Fetner, Christopher D.; Barilla, Donald E.; Townsend, J C; Pak, Charles Y.C.

doi:10.1016/s0022-5347(17)57198-0

Cited by 44 publications

(15 citation statements)

References 11 publications

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“…Tiselius et al [21] administered magnesium in the form of magnesium oxide to calcium oxalate stone formers and showed that higher magnesium outputs led to an increased calcium excretion. An increased excretion of calcium was also demonstrated by Fetner et al [9] . In our study, we found only a slight increase in calcium excretion.…”

Section: Discussionsupporting

confidence: 59%

“…Liebman and Costa [8] even concluded that magnesium is nearly as effective as calcium in reducing oxalate absorption and urinary excretion in healthy volunteers. However, some clinical studies with a small number of patients were unable to demonstrate a statistically signifi cant benefi cial effect of magnesium [9][10][11] . These contradictory results have rendered it diffi cult to draw distinct conclusions regarding the effi cacy of magnesium in prophylactic treatment.…”

Section: Introductionmentioning

confidence: 99%

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Importance of Magnesium in Absorption and Excretion of Oxalate

Zimmermann¹,

Voß²,

Unruh³

et al. 2005

Urol Int

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Introduction: Magnesium treatment for calcium oxalate urolithiasis is discussed controversially. The aim of this study was to investigate the influence of magnesium supplementation on the oxalate absorption. Materials and Methods: The [¹³C₂]oxalate absorption test was always performed three times in 6 healthy volunteers under standardized conditions, with one 10-mmol magnesium supplement together with the labeled oxalate and with two 10-mmol magnesium supplements given in 12-hour intervals. Results: The mean intestinal oxalate absorption under standard conditions was 8.6 ± 2.83%. The oxalate absorption with one 10-mmol magnesium supplement was 5.2 ± 1.40% and with two supplements 5.5 ± 1.62%. Both decreases were statistically significant relative to the standard test, however, not significantly different from each other. Conclusions: The results show that magnesium administration decreases the oxalate absorption, when magnesium is taken together with oxalate. However, magnesium administration does not decrease the oxalate absorption, when magnesium and oxalate intake differ by 12 h.

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Section: Discussionsupporting

confidence: 59%

Section: Introductionmentioning

confidence: 99%

Importance of Magnesium in Absorption and Excretion of Oxalate

Zimmermann¹,

Voß²,

Unruh³

et al. 2005

Urol Int

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“…Our results suggest that high urinary magnesium can increase calciuria and potentially increase stone risk. Some have espoused the notion that magnesium is efficacious in preventing stone formation by binding or complexing oxalate in the bowel and urine, 26,27,40,41 by inhibiting calcium oxalate crystal formation, 26,42,43 and by increasing urinary citrate when given as alkali salt. 44 In vitro studies have shown that magnesium is an inhibitor of calcium oxalate crystal growth in artificial, rodent, and human urine but at supraphysiologic concentrations.…”

Section: Discussionmentioning

confidence: 99%

Mechanism of Urinary Calcium Regulation by Urinary Magnesium and pH

Bonny

Rubin

Huang

et al. 2008

Journal of the American Society of Nephrology

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Urinary magnesium and pH are known to modulate urinary calcium excretion, but the mechanisms underlying these relationships are unknown. In this study, the data from 17 clinical trials in which urinary magnesium and pH were pharmacologically manipulated were analyzed, and it was found that the change in urinary calcium excretion is directly proportional to the change in magnesium excretion and inversely proportional to the change in urine pH; a regression equation was generated to relate these variables (R 2 ϭ 0.58). For further exploration of these relationships, intravenous calcium chloride, magnesium chloride, or vehicle was administered to rats. Magnesium infusion significantly increased urinary calcium excretion (normalized to urinary creatinine), but calcium infusion did not affect magnesium excretion. Parathyroidectomy did not prevent this magnesium-induced hypercalciuria. The effect of magnesium loading on calciuria was still observed after treatment with furosemide, which disrupts calcium and magnesium absorption in the thick ascending limb, suggesting that the effect may be mediated by the distal nephron. The calcium channel TRPV5, normally present in the distal tubule, was expressed in Xenopus oocytes. Calcium uptake by TRPV5 was directly inhibited by magnesium and low pH. In summary, these data are compatible with the hypothesis that urinary magnesium directly inhibits renal calcium absorption, which can be negated by high luminal pH, and that this regulation likely takes place in the distal tubule. 19: 153019: -153719: , 200819: . doi: 10.1681 The amount of calcium excreted in the urine (calciuria) is tightly regulated by a complex interaction between numerous calcitropic hormones, extracellular volume, acid-base status, and plasma and urinary concentration of various ions. 1 Calciuria is a continuous trait in the general population, and hypercalciuria is a major risk factor for nephrolithiasis found in high incidence in the stone former and/or in the osteoporotic populations. 2 The first description of an effect of magnesium on calciuria was made in a seminal article by Mendel and Benedict in 1909. 3 They observed increased calcium excretion and decreased fecal calcium content when magnesium salts were injected to various animal species. Similar observations were later reported in humans in preeclamptic pregnant women who were treated with magnesium sulfate and in normal individuals. 4,5 This effect was attributable to magnesium and not sulfate. 6 Attempts have been made to localize the segment where urinary magnesium could mediate its effect on calcium reabsorption in different animal models. Metabolic experi- J Am Soc Nephrol

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“…There have been several reports [3][4][5][6][7] indicating that magnesium oxide or hydroxide may be useful in the management of recurrent calcium oxalate nephrolithi asis. It was believed that magnesium may act as an in hibitor of crystallization in the urine [8] and may bind oxalate in the gut [9].…”

Section: Introductionmentioning

confidence: 99%

Magnesium bioavailability from magnesium citrate and magnesium oxide.

Lindberg

Zobitz

Poindexter

et al. 1990

Journal of the American College of Nutrition

121

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This study compared magnesium oxide and magnesium citrate with respect to in vitro solubility and in vivo gastrointestinal absorbability. The solubility of 25 mmol magnesium citrate and magnesium oxide was examined in vitro in solutions containing varying amounts of hydrochloric acid (0-24.2 mEq) in 300 ml distilled water intended to mimic achlorhydric to peak acid secretory states. Magnesium oxide was virtually insoluble in water and only 43% soluble in simulated peak acid secretion (24.2 mEq hydrochloric acid/300 ml). Magnesium citrate had high solubility even in water (55%) and was substantially more soluble than magnesium oxide in all states of acid secretion. Reprecipitation of magnesium citrate and magnesium oxide did not occur when the filtrates from the solubility studies were titrated to pH 6 and 7 to stimulate pancreatic bicarbonate secretion. Approximately 65% of magnesium citrate was complexed as soluble magnesium citrate, whereas magnesium complexation was not present in the magnesium oxide system. Magnesium absorption from the two magnesium salts was measured in vivo in normal volunteers by assessing the rise in urinary magnesium following oral magnesium load. The increment in urinary magnesium following magnesium citrate load (25 mmol) was significantly higher than that obtained from magnesium oxide load (during 4 hours post-load, 0.22 vs 0.006 mg/mg creatinine, p less than 0.05; during second 2 hours post-load, 0.035 vs 0.008 mg/mg creatinine, p less than 0.05). Thus, magnesium citrate was more soluble and bioavailable than magnesium oxide.

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Effects of Magnesium Oxide on the Crystallization of Calcium Salts in Urine in Patients with Recurrent Nephrolithiasis

Cited by 44 publications

References 11 publications

Importance of Magnesium in Absorption and Excretion of Oxalate

Importance of Magnesium in Absorption and Excretion of Oxalate

Mechanism of Urinary Calcium Regulation by Urinary Magnesium and pH

Magnesium bioavailability from magnesium citrate and magnesium oxide.

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