Reply to "Recommendation on an updated standardization of serum magnesium reference ranges," Jeroen H.F. de Baaij et al

We thank de Baaij et al. [1] for their provocative and thoughtful letter regarding our paper on the need to standardize serum magnesium reference ranges in clinical medicine [2]. We are especially pleased that the authors emphasize the essential role of magnesium in health and disease and the importance of measuring serum magnesium in the clinical setting. We also thank the authors for their appraisal of cohort studies and randomized clinical trials relative to magnesium reference ranges that may interest the readership of the European Journal of Nutrition. However, we would like to emphasize that any discussion related to the measurement of serum magnesium needs to consider that even the gold-standard methods have limitations [3, 4].