While eating foods rich in calcium has protective effects against kidney stones, the effect of supplementation with calcium and vitamin D on the risk of kidney stone formation remains unclear.
Patients who took calcium supplements had lower total calcium and oxalate (which are components of kidney stones) in their urine while blood levels were unaffected.
While taking supplemental calcium has associated positive effects, these results suggest that supplemental, as compared with dietary, calcium may worsen stone disease for patients who are known to form kidney stones
