I know this is anecdotal evidence, but my granddad took multivitamins faithfully for years. After my grandma passed from cancer, and due to not eating as much food with those vitamins, his body had a calcium build up to a state of calcium poisoning. This did a number on his kidneys. His kidneys did not recover. Instead of dialysis , he chose hospice. Multivitamins have the potential to give too much for the body to handle.