Vitamin D Status in Patients with Recurrent Kidney Stones

Abstract

Data regarding the prevalence of 25-hydroxyvitamin D (25(OH)D) insufficiency in patients with nephrolithiasis, and the effects of vitamin D supplementation on parathyroid hormone (PTH) are few and conflicting. In this article, we examined the prevalence of vitamin D insufficiency and deficiency in 236 recurrent kidney stone formers and the correlation of vitamin D levels with other parameters of stone formation. The prevalent stone composition was calcium oxalate (80.4%) and uric acid (16.45%). One third of stone formers had vitamin D insufficiency and a quarter of them high PTH levels (PTH >7.5 pmol/l) with normal serum (total and ionized) calcium values. Predictor of high PTH was low 25(OH)D level (r = 0.989, r² = 0.977, p < 0.001). Stone formers with hypercalciuria had higher 25(OH)D values (72.26 ± 4.21 vs. 59.29 ± 1.76, p = 0.0013) compared to stone formers with urine calcium within normal ranges. Further studies are needed in order to better define the consequences of vitamin D insufficiency and to evaluate the impact of the therapeutic interventions in this cohort.

Pathogenesis of calcium oxalate urinary stone disease: species comparison of humans, dogs, and cats

“…Too little vitamin D may also play a role in stone formation, as deficiency or insufficiency has been linked to increased risk of calcium nephrolithiasis [34, 35]. Other compounds that modulate urinary stone formation are glycosaminoglycans and proteins (including Tamm-Horsfall protein, nephrocalcin, osteopontin, inter-α-inhibitor, urinary prothrombin fragment-1, calgranulin) [36, 37].…”

Study of lithogenic factors in men and women with recurrent nephrolithiasis in the north area of Almeria

“…Tras el análisis de correlación lineal que observamos en la tabla 4, vemos que existen múltiples relaciones significativas, quizá la más interesante es la relación lineal positiva y significativa entre los niveles de sodio y de calcio en orina, lo que indica que a mayor excreción en orina de sodio, aumenta la calciuria, resultados que corroboran lo ya observado en otros estudios que indican que la mayor ingesta de sal aumenta el riesgo de hipercalciuria (22). Otro aspecto destacable del estudio es que las mujeres, aunque presentan menores factores de riesgo litógeno en orina, tienen un mayor porcentaje de hipovitaminosis D con respecto a los hombres, estando este factor de forma global más presente en pacientes formadores habituales de litiasis (23,24), aunque no se ha aclarado todavía cuál es su papel real en la fisiopatología de la litiasis urinaria. No obstante, este déficit de vitamina D podría inducir de forma secundaria un hiperparatiroidismo que sería el responsable del aumento de calcio en orina y la mayor incidencia de litiasis.…”

CUA guideline on the evaluation and medical management of the kidney stone patient ‒ 2016 update

“…56 Studies are conflicting when vitamin D levels were compared to urinary calcium excretion. Some studies noted an association between higher vitamin D levels and hypercalciuria, 57,64 whereas other studies did not note an association between vitamin D and hypercalciuria 65 or stone reccurrence. 66 The impact of vitamin D supplementation on hypercalciuria and stone risk has also been assessed by multiple conflicting studies.…”

“…56 In other stone populations, inadequate vitamin D was noted in one-third of 236 recurrent calcium stone-formers. 57 Many studies have examined the association between low bone mineral density, osteopenia, osteoporosis, fracture risk, and calcium nephrolithiasis. Patients with renal stones have associated low bone mineral density in several studies, with increasing risk correlating with increasing levels of hypercalciuria.…”