Background: Over the last decade, clinical interest to evaluate human 25-hydroxy-vitamin D
(25 [OH] D) serum levels has increased exponentially. In the present study, four …

BACKGROUND Recent recognition of its broad pathophysiological importance has
triggered an increased interest in 25-hydroxyvitamin D [25 (OH) D]. By consequence …

Background The most reliable assessment of vitamin D status is measurement of plasma 25-
hydroxyvitamin D (25 [OH] D) concentration. High variability in 25 (OH) D measurements …

BACKGROUND: Historically, methodological differences and lack of standardization led to
between-laboratory variability in 25 (OH) D results. Recent observations raised concern …

This interlaboratory study on determination of 25-hydroxyvitamin D (25-OH-D) in serum
involved 15 laboratories in eight European countries. All could distinguish between normal …

Objectives: the different analytical methods for measurement of serum 25-hydroxyvitamin D
(25 (OH) D) are not yet fully harmonized and no consensus exists on a threshold of 25 (OH) …

Context: Measurement of circulating 25-hydroxy-vitamin D [25 (OH) D]) is the accepted
clinical indicator of vitamin D status. However, between-laboratory differences in …

25-Hydroxyvitamin D (25-OHD) 1 is the most appropriate marker for monitoring vitamin D
storage status. The 2 major forms of 25-OH-D [25-OH-D2 (D2) and 25-OH-D3 (D3)], differ …

Objectives The ability of current immunoassays to accurately measure equimolar amounts of
25 (OH) D 2 and 25 (OH) D 3 has been recently questioned. This study determined serum …

OBJECTIVES: The performance of recently developed vitamin D total assays (ADVIA
Centaur and Elecsys) was compared to that of liquid chromatography–tandem mass …