Quest Says Vitamin D Test Problem Fixed

A medical lab company said it has fixed a problem with tests for vitamin D levels in the blood. The problem led to readings that were too high on some tests, Quest Diagnostics said. Quest said it discovered the problem because vitamin D levels found in tests were rising for no apparent reason. The company notified doctors and offered free repeat tests for some patients. Tests for vitamin D have been rising. Quest said there’s more interest now. That’s because new research suggests low vitamin D may increase the risk of cancer and heart disease. The Associated Press wrote about the Quest announcement January 8.