What foods should I avoid or minimize if I'm a vegetarian and have a kidney stone (calcium)?

Kidney stones. Do you know the composition of your stone? If it's a cacium stone,avoid dairy products which are high in calcium. Uric acid stones are a different matter. Blood tests are recommended if you continue to form kidney stones.Your physician is best to advise you as he/she knows your findings.
Here are some ... Without stone work-up, I wouldn't provide a specific recommendation for stone prevention, but I urge my patients with recurrent stones to maintain daily urine output >2,500 cc and to decrease oral consumption of salt, red meat, & dairy products by >35-50%, because the cause for stone is chiefly hereditary.The whole bottom line of stone prevention is keep urine diluted enough not to form crystals.