Description
In the past decade or two the prevalence of vitamin D deficiency has increased. In addition to its role in calcium and bone homeostasis vitamin D is now implicated in many other physiological processes. This has led to numerous studies which have shown that vitamin D deficiency is a risk factor for many
diseases including diabetes mellitus, cardiovascular disease, malignancy, and multiple sclerosis. Most of these studies are epidemiological studies showing association between low vitamin D status and the risk of disease. This and other factors have led to the exponential growth in vitamin D requests in all
clinical laboratories. In order to manage this workload many laboratories have switched to fully automated immunoassays. One of the confounding factors in the assessment of vitamin D status is the poor quality of the assays used in many laboratories. Data from external quality assurance schemes show that there is large variation in results between laboratories. In the first article in this issue Dr Rosemary Clarke discusses the various assays and their strengths and
weakness. In the more than an abstract section three articles related to this topic are described.
Hyponatraemia is common in clinical practice and in the last issue we discussed sodium and water homeostasis, general aspects of hyponatraemia and one specific condition, exercise induced hyponatremia. In this issue another hyponatraemia topic is discussed, namely cerebral salt wasting. For many years cerebral salt wasting was regarded as a variant of syndrome of inappropriate ADH syndrome (SIADH). However recent studies suggest that cerebral salt wasting is distinct from SIADH and identification of this condition is important to avoid improper treatment which may be harmful. The controversy surrounding cerebral salt wasting and the possible pathogenic mechanisms are discussed in the second article.
Finally, we would like to invite readers to submit interesting case
reports that have a particular educational message. The Bulletin will become more lively and interesting with more contribution from readers.
