Many of the studies on the effects of supplements on kidney stones have focused on the impact of supplementation on the risk of developing stones. Vitamin C has been studied frequently, since it’s converted to oxalate after ingestion and excreted via the urine, which could potentially promote stone formation by increasing oxalate levels in the urine.
A couple of studies found a high vitamin C intake was associated with an increased risk of kidney stone risk in men.[1][2] An additional study found evidence that a high intake of vitamin C from supplements was likely responsible for the increased kidney stone risk in men.[3]
Other notable supplements that have been studied for their effect on kidney stones include caffeine,[4] calcium, and vitamin D.[5]