Study of Potassium Phytate Effects on Decreasing Urinary Calcium in Rats

Abstract

Background: Phytate as sodium salt has been used at high doses to treat stone-former patients with idiopathic hypercalciuria. The experimental and clinical hypocalciuric effects of dietary fiber have also been assigned to the presence of phytate as calcium-magnesium salt (phytin). As a consequence of the additional interest in phytate due to its capacity as crystallization inhibitor, now a study of the effects of potassium phytate on urinary calcium excretion is presented and compared with the effects caused by other phytate salts. Methods: To study the effect of calcium-magnesium phytate, 36 Wistar rats (6 groups) were fed with a purified diet in which phytate was practically absent (4068.02 Reference Diet). Three groups were fed with increasing calcium amounts and with the same amount of phytin, each one corresponding to one control group. To study the effects of magnesium-potassium, sodium and potassium phytate salts, 48 Wistar rats (8 groups) were fed with UAR-A04 diet (a standard diet which contains 0.8% of phytin). Two control groups fed with low and high calcium amounts and 6 treated groups were formed. The effect of the dose of potassium phytate on urinary calcium was carried out using 2 additional groups of 6 Wistar rats each one fed with UAR-A04 diet and increasing amounts of potassium phytate. Results: No significant changes in urinary calcium were observed when phytin (calcium-magnesium phytate) was supplied. The urinary calcium was clearly reduced by the three phytate salts assayed (magnesium-potassium, sodium, potassium), but the most significant decrease was noticed when the potassium phytate salt was administered. Phytate administration, independently of the salt or dose used, did not significantly affect the urinary oxalate. Conclusion: It can be clearly deduced that the effects of phytate on the urinary parameters, mainly calcium, fundamentally depend on the type of salt used. Thus, the most remarkable effects on urinary calcium reduction were caused by the potassium salt. Obviously, these findings must be confirmed in human studies.

Dietary Therapy in Idiopathic Nephrolithiasis

“…In rats, potassium phytate reduces calcium excretion. 59 The Nurses' Health Study II 5 reported a strong inverse relationship between phytate intake and stone risk, with the women in the highest quintile of phytate intake having a 36% lower risk of stone formation. However, in men, there was no relationship between phytate intake and stone risk.…”

Urinary pH as a Target in the Management of Lithiasic Patients in Real-World Practice: Monitoring and Nutraceutical Intervention for a Nonlithogenic pH Range

“…Both molecules are crystallization inhibitors, and they work synergistically with pH correctors, reducing the nucleation and crystallization. [22][23][24][25][26][27] In addition, the survival analyses showed that, once the urinary pH became nonlithogenic, free-survival rates of selfreported colic events improved. Although this result should be interpreted with caution, it shows a relationship between the reduction in renal lithiasis-related events and a nonlithogenic pH.…”

“…Both molecules are crystallization inhibitors, and they work synergistically with pH correctors, reducing the nucleation and crystallization. 22–27…”