The consequences of excessive intake of vitamin C are as follows: 1. It may lead to a high risk of urinary stones, because one of the metabolites of vitamin C is oxalate, and if too much vitamin C is consumed, a large amount of oxalate is excreted through the urinary system, which may increase the incidence of urinary stones. 2. 3, may cause infertility, because too much vitamin C can cause the cervical mucus to prevent the penetration of sperm, which may cause a high incidence of infertility.