Annemieke Heijboer, PhD, is Professor of Endocrine Laboratory Medicine and head of the Endocrine Laboratory of the Amsterdam UMC in Amsterdam, the Netherlands. Annemieke obtained her PhD at the Leiden University in the Netherlands in 2006 and went to Amsterdam (VU University medical center) to be trained as clinical chemist with later on a specialization in endocrinology. Since 2010 she is heading the Endocrine Laboratory of the VU University medical center which she merged with the Laboratory of Laboratory of Endocrinology of the Amsterdam Medical Center, being the Endocrine Laboratory of the Amsterdam UMC since 2018. She is member of the Bone committee of the IFCC and chair of Endocrine committee of the Dutch Society for Clinical Chemistry. Her interests are clinical chemistry and hormones, with a special interest in steroid hormones, amongst which vitamin D.