The investigator's objective is to compare and evaluate the impact of nutritional treatment vs. pharmacological treatment (hydrochlorothiazide) in bone mineral density in children with idiopathic hypercalciuria.

A randomized, open-label, one-year follow-up study will be conducted in children aged 5 to 21 years with a confirmed diagnosis of idiopathic hypercalciuria or lithiasis, excluding those patients with secondary hypercalciuria (primary hyperoxaluria, treatment with vitamin D, Bartter syndrome, primary hyperparathyroidism), previous kidney transplantation. The impact of diet (hyposodic, calcium intake according to DIR for age, normal protein intake and high water intake) will be evaluated vs. the pharmacological treatment (hydrochlorothiazide) on bone mineral density.

A randomized, open-label clinical trial will be conducted with a one-year follow-up. For which basal measurement of calciuria, citraturia, serum creatinine, serum and urinary electrolytes, parathyroid hormone, vitamin D levels and renal ultrasound, as well as dietary intake (protein, energy, salt and water). The dietary intake per day of food and pharmacological treatment will be evaluated quarterly, body composition (anthropometry) and serum and urinary electrolyte levels will be measured; Bone constitution (DXA, quantitative bone ultrasound), IL-1 (as inflammatory markers) and vitamin D will be evaluated every six months.

Participants will be blinded to the pharmacological treatment they will receive. The randomization of the participants will be done through the page www.randomization.com. The randomization was performed by blocks, where blocks of 6 members each were made i. Group 1: only recommendations of water intake and reduction of salt intake and hydrochlorothiazide will be given (the dose will be assigned according to weight and sex by a pediatric nephrologist, dose of 0.5-1.5mg / kg / day, starting with the dose 1 mg / kg). Hydrochlorothiazide will be provided to the patient.

ii. Group 2: placebo capsules and a strict diet plan will be given. The placebo will look similar to that of hydrochlorothiazide and will be prepared in the Nephrology Research Laboratory by Biol. Ana María Hernández Sánchez and Quim Lourdes Ortiz. The feeding plan will be appropriate for the patient, it will consist of:

1. 40 ml / Kg / day of water
2. Protein according to age and sex
3. Recommendations for low sodium intake
4. Calcium according to age and sex (minimum 800mg)

Inclusion Criteria:

• Clinical diagnosis of idiopathic hypercalciuria
• Man or women
• 5 to 21 years

Exclusion Criteria:

• Clinical diagnosis of secondary hypercalciuria (primary hyperoxaluria, treatment with vitamin D, Bartter syndrome, primary hyperparathyroidism)
• Previous kidney transplant
• Clinical diagnosis of kidney disease.
• Vitamin D intake (more than 800 mg/day)

a report of results will be made by means of a research article and information will be provided that researchers interested in the obtained data request

will be available at within one year

Requests for additional information will be reviewed by Nutriologa Ma Elena Ortiz and PhD. Mara Medeiros Domingo

The capsules are the same color in the placebo group and the intervention group. The content of the capsules is similar in both groups.