Guiding Appropriate Laboratory Test Utilization: 1,25-OH-Vitamin D

The laboratory test utilization management toolbox

Efficiently managing laboratory test utilization requires both ensuring adequate utilization of needed tests in some patients and discouraging superfluous tests in other patients. After the difficult clinical decision is made to define the patients that do and do not need a test, a wealth of interventions are available to the clinician and laboratorian to help guide appropriate utilization. The...

Defining vitamin D deficiency in children: beyond 25-OH vitamin D serum concentrations.

Effects of vitamin D binding protein phenotypes and vitamin D supplementation on serum total 25(OH)D and directly measured free 25(OH)D

OBJECTIVE To determine the relationship between serum total 25-hydroxyvitamin D (25(OH)D), directly measured free 25(OH)D and calculated free 25(OH)D with regard to vitamin D-binding protein (DBP) phenotypes, sex, BMI, age and season, and their interrelationship to vitamin D supplementation. DESIGN, PATIENTS AND INTERVENTIONS A randomized controlled trial with 20 000 IU of vitamin D3 per week...

25(OH)D and 1,25(OH)D vitamin D fails to predict sepsis and mortality in a prospective cohort study

The clinical role of vitamin D in sepsis and mortality prediction is controversially discussed. Therefore, we conducted a prospective cohort study on standard care wards, including 461 patients with suspected sepsis fulfilling two or more SIRS criteria. On the first and third day after onset of SIRS symptoms levels of 25(OH)D, 1,25(OH)D and sepsis biomarkers were analysed for their predictive c...

Vitamin D and 1,25(OH)2D Regulation of T cells

Vitamin D is a direct and indirect regulator of T cells. The mechanisms by which vitamin D directly regulates T cells are reviewed and new primary data on the effects of 1,25 dihydroxyvitamin D (1,25(OH)2D) on human invariant natural killer (iNK)T cells is presented. The in vivo effects of vitamin D on murine T cells include inhibition of T cell proliferation, inhibition of IFN-γ, IL-17 and ind...