An 89-year-old retired businessman died from an “overdose” of Vitamin D supplements that did not warn about the risks of excessive intake.
David Mitchener from Oxted, Surrey, reportedly had fatally high levels of Vitamin D when he was brought to the East Surrey Hospital last year in May and was suffering from hypercalcaemia – a build-up of calcium in the body associated with taking too much vitamin D.
He died ten days later.
note that's only a concern for fat soluble vitamins (A, D, E, and K). the rest you just piss out