The New York Times reported on January 7 that Quest Laboratory had experienced substantial unreliability of its vitamin D determinations for the past two years. There appeared to have been various technology issues that resulted in both high and low values reported. The problems are said to have been corrected.
We have checked and only a very few of our patients’ vitamin D blood levels were performed at Quest. The vast majority were done at the Newton-Wellesley Hospital lab, which (at least for the moment) does not seem to have had reliability problems with this test. So we believe our recommendations to you and the results reported to you on vitamin D deficiency and corrective action we recommended were correct.
We clearly will continue to monitor this issue carefully. Lab testing always has to be looked at carefully for consistency and possible errors.