Natasja M van Schoor, Paul Lips

PMID: 33517482 PMCID: PMC7847293 DOI: 10.1007/s00431-021-03968-6


The aim of the present study is to summarize existing literature on vitamin D levels in adults in different continents and different countries worldwide. The best determinant of vitamin D status is the serum concentration of 25-hydroxyvitamin D (25(OH)D). Most investigators agree that serum 25(OH)D should be higher than 50 nmol/l, but some recommend higher serum levels. Traditional risk groups for vitamin D deficiency include pregnant women, children, older persons, the institutionalized, and non-western immigrants. This chapter shows that serum 25(OH)D levels are not only suboptimal in specific risk groups, but also in adults in many countries. Especially, in the Middle-East and Asia, vitamin D deficiency in adults is highly prevalent.

Keywords: Vitamin D, 25-Hydroxyvitamin D 2, Calcifediol