The reason for high calcium oxalate crystals is mainly the consumption of a large amount of food containing oxalic acid, such as strong tea, spinach, asparagus, peanuts, tomatoes, etc.. In this case, we must drink more water, control the intake of food with high oxalate content, and also take oral vitamin B6 to reduce the excretion of oxalate. You can also take oral magnesium oxide to increase the solubility of oxalic acid in urine. For high calcium oxalate crystals, with further increase in concentration, will be in the kidneys for calcium oxalate crystals deposition, aggregation increase into calcium oxalate stones, stone increase will lead to hydronephrosis, and eventually kidney failure may occur.