An article published by the Canadian Medical Association indicates that excessive intake of vitamin D can cause kidney damage in individuals who do not have a deficiency in this vitamin or who consume it excessively without medical supervision. The lead author of the study, Bourne August from the University of Toronto, Canada, told Medscape Medical News, "The goal of case studies is to inform more people that taking high doses of vitamin D in those with normal vitamin D levels can lead to toxicity and impaired kidney function."
The study cited the case of a 54-year-old man who was hospitalized due to suspected severe kidney enlargement. Doctors found a high level of creatinine in the patient's blood, which typically indicates serious kidney problems. Further examination revealed calcium deposits in the patient’s kidneys.
The man explained that his therapist prescribed him large doses of vitamin D and admitted to taking the supplement in excess of the recommended amount. He mentioned that he bought an incorrect dose and therefore consumed around 8,000 to 12,000 International Units of vitamin D daily for two and a half years. Even after receiving medical care, the man continued to suffer from irreversible chronic kidney failure. Studies confirm that those who take large doses of vitamin D can quickly become toxic, with symptoms including nausea, vomiting, weakness, and frequent urination.
