Several researchers have shown that a reduced intake of vitamin B6 can induce increased oxalate urinary excretion leading to a higher incidence of calcium oxalate stones. Furthermore, the treatment with pyridoxine in patients with urinary stones and high oxalate excretion has led to contradictory results as the excretion of oxalate was either decreased, unchanged or increased. To verify if these divergent results were linked to a different B6 status of the patients undergoing the treatment, we studied the vitamin B6 and the main lithogenetic factor levels in patients with idiopathic calcium lithiasis as compared to normal subjects. The results showed that a high oxalate excretion is not necessarily coupled with a low vitamin B6 status and viceversa. However, some stone formers present a non homogeneous vitamin pattern that could be the consequence of an abnormal vitamin B6 metabolism.