Aim: To study the impact of vitamin D supplementation on vitamin D concentration in plasma, calcium urinary excretion and bone density in patients with urolithiasis in the course of idiopathic hypercalciuria and with a low vitamin D level.
Materials and method: Prospective analysis concerning 28 patients (16 boys, 12 girls) aged 6-14 years (average 10.4) in terms of urinary calcium excretion (mg/kg/day and Ca/Creatinine ratio in morning urine sample), 25OHD blood level after 3, 6, 9 and 12 months of individually recommended doses of vitamin D supplementation (400 IU or 800 IU). The doses were determined on the basis of 25 (OH) D deficiency. The children were on a normocalcemic diet. The bone mineral density of the patients was assessed before and after 12 months of vitamin D use at the aforementioned doses.
Results: There was no statistically significant correlation between 25 (OH) D plasma concentration and urinary calcium excretion measured on Ca /Creatinine ratio in daily urine collection and Ca/Creatinine ratio in the morning urine sample. No statistically significant change in calcium excretion was noted (measured by calciuria in daily urine collection and the calcium to creatinine ratio in the morning urine sample). A statistically significant increase in vitamin D plasma concentration was observed. Improvement in bone mineral density was not statistically significant.
Conclusions: Supplementation of vitamin D in the children with idiopathic hypercalciuria and urolithiasis who were examined seems to be safe. The decision to start treatment and the selection of the vitamin D dose should be considered individually. Patients with urolithiasis should be carefully monitored for calcium/phosphate metabolism parameters and the activity of the disease. Supplementation of low doses vitamin D in the children examined did not improve bone mineral density.
Keywords: bone density; children; hypercalciuria; urolithiasis; vitamin D.