Effect of phytate on hypercalciuria secondary to bone resorption in patients with urinary stones: pilot study

Abstract

The objective is to evaluate the effect of phytate supplements on calciuria in patients with urinary stones and elevated bone resorption. The secondary objective is to analyze the therapeutic effect of phytate based on measurements of serum markers of bone resorption. This is a controlled randomized study included patients according to predefined inclusion and exclusion criteria, and randomized them into two groups. Patients in the phytate group received a 380 mg capsule of calcium-magnesium InsP6 (Salvat Laboratories®) every 24 h for 3 months and patients in the control group received no treatment. All included patients were male or female, 18–65 years old, had hypercalciuria (> 250 mg/24 h), had a ß-Crosslaps level greater than 0.4 ng/mL, and had bone densitometry results indicative of osteopenia or osteoporosis in the femur and/or spine. At study onset, calciuria was 321 ± 52 mg/24 h in the phytate group and 305 ± 57 mg/24 h in the control group (p > 0.05). At 3 months, calciuria was significantly lower in the phytate group than the control group (226 ± 45 mg/24 h vs. 304 ± 58 mg/24 h, p < 0.05). At study onset, the mean ß-CrossLaps level was 1.25 ± 0.72 ng/mL in the phytate group and 0.57 ± 0.13 ng/mL in the control group (p < 0.05). However, at 3 months, the ß-CrossLaps level was significantly lower in the phytate group than in the control group (0.57 ± 0.13 ng/mL vs. 0.77 ± 0.42 ng/mL, p < 0.05). Phytate reduced calciuria in patients with hypercalciuria secondary to bone resorption. The ß-CrossLaps assay was effective for evaluating the efficacy of phytate on hypercalciuria during follow-up.

Effect of Phytate (InsP6) and Other Inositol-Phosphates (InsP5, InsP4, InsP3, InsP2) on Crystallization of Calcium Oxalate, Brushite, and Hydroxyapatite

“…For example, previous research reported that InsPs can inhibit osteoclastogenesis and mineralization of osteoblasts [33]. Another recent study showed that the intake of InsP6 by menopausal women with hypercalciuria significantly decreased the elimination of urinary calcium [34]. In these cases, phytate or its derivatives do not act as crystallization inhibitors, but due to their activity at the cellular level, the elimination of urinary calcium decreases, so the supersaturation of calcium salts also decreases, and as a consequence their ability to crystallize.…”

Recurring renal lithiasis due to Dent’s disease

“… 4 Additionally, we added phytate owing to its capacity to inhibit calcium phosphate lithiasis growth and to decrease bone resorption. 5 …”

Cellular and Molecular Activities of IP6 in Disease Prevention and Therapy

“…Interestingly, although the mechanisms involved in bone metabolism differ from those of kidney stone formation, some similarity exists, especially with regard to the inorganic ions that are involved in the process. IP6 was shown to reduce calciuria in patients with hypercalciuria because of increased bone resorption, resulting in a reduced tendency for kidney stone formation in these patients [ 171 ]. The beneficial effects of IP6 with regards to bone health may be attributable to the protective role in bone decalcification by combining with hydroxyapatite, thereby reducing the rates of its dissolution [ 64 ] ( Table 1 ).…”