Vitamin D Metabolism and the Risk of Renal Stones: A Focus on PHPT

: Primary hyperparathyroidism is nowadays a common endocrine disorder. Over time, the clinical manifestation has shifted from symptomatic cases to mostly asymptomatic diagnoses. Despite this, nephrolithiasis remains significant, often presenting as bilateral and recurrent, with the literature reporting prevalence rates of up to 40%. The nephrolithiasis pathogenesis in PHPT is multifactorial and not fully understood. While elevated PTH increases urinary calcium load, additional urinary abnormalities and demographic factors, including age and sex, influence the risk. Vitamin D status has also been explored as a possible contributor to stone formation both in the general population and in PHPT patients. The relationship between serum 25OHD levels and nephrolithiasis remains unclear, and the impact of vitamin D supplementation on stone risk in PHPT is still under investigation. The relationship between vitamin D status, supplementation and renal stones in PHPT is explored in the present review.