Reference intervals for plasma vitamin B12 and plasma/serum methylmalonic acid in Danish children, adults and elderly.

Background: Plasma/serum vitamin B12 (B12) is often used to screen for B12 deficiency complemented with analysis of methylmalonic acid (MMA) in case of low B12. The concentration of both analytes likely depends on age, and we, therefore, aimed at establishing 95% age-adjusted reference intervals (RIs) for plasma B12 and serum/plasma MMA in the Danish population.

Methods: We collected and analysed blood samples from healthy children, adults, and elderly individuals and extracted routine clinical B12 and MMA results to establish RIs.

Testosterone Measured with an Automatic Immunoassay Compares Reasonably Well to Results Obtained by LC-MS/MS.

Background: Previous studies have reported problems measuring testosterone with immunological assays. Here we explore an automatic second generation immunoassay compared to a LC-MS/MS method.

Methods: We collected blood samples from 76 women and measured testosterone, progesterone, gender hormonebinding globulin (SHBG), and albumin employing Cobas e601/c501.