Pre-Analytical Factors Influence Vitamin D Measurement In Clinical Laboratory

Abstract

Abstract:It has been more than 90 years since the discovery of vitamin D and its capability to cure rickets in children. Recently, awareness is growing of the prevalence of vitamin D deficiency in the general population in association with an increased risk of several diseases. Analyses of vitamin D levels in blood samples provide direct measures of exposure to dietary or supplemented vitamin. This review is focused on the pre-analytical factors and challenges are known to affect the concentrations of vitamin D biomarkers. The pre-analytical measurement of disease relevant vitamin D deficiency in blood can vary as a function of differences in sample handling and processing. It could impact the accurate measurement of the diseases relevant vitamin D deficiency. Majority of the analysis in a clinical biochemistry laboratory requires serum or plasma as the analytical specimen and obtaining serum or plasma from a primary sample is an important step of pre-analytical procedure. Although vitamin D is considered as a relatively stable analyte, effect of pre-analytical conditions and stability of vitamin D in serum and plasma needs to be identified clearly.

Challenges Ahead for a Rational Analysis of Vitamin D in Athletes

“…The 27 articles in connection with vitamin D in the sports sector were read in full, discussed comprehensively, and the data from some selected articles were presented as graphics. The 27 relevant studies were organized into five controversial topics, more specifically, assay variability (20)(21)(22)(23)(24)(25)(26)(27)(28), sample/assay comparability (8,9,12,27,29,30), intake ranges (12,20,(31)(32)(33)(34), statistical power (12,(35)(36)(37)(38), and preanalytical factors (28,(39)(40)(41)(42)(43), that were comprehensively discussed. Out of all the records, 33% were used to discuss assay variability; 22% for sample/assay comparability, intake ranges, and preanalytical factors; and 19% for statistical power.…”

“…A qualitative checking of the 27 records indicated that 37, 40.7, and 3.7% of the analyzed references were published in peer-reviewed journals with current impact factors ranging between 5–8.6 ( 8 , 9 , 22 , 23 , 30 , 31 , 33 – 35 , 39 ), 2.4–4. ( 12 , 21 , 27 – 29 , 32 , 36 , 38 , 40 , 41 , 43 ), and 1.2 ( 39 ), respectively. There was one article, representing 3.7% of the records, that was published in a peer-reviewed journal of the Norwegian Medical Association without impact factor ( 37 ).…”

“…It is vital to adopt strategies for understanding and preventing the underlying mechanisms of preanalytical factors with larger sample sizes. Besides, analytical and post-analytical factors must also be considered to determine robust reference values, define more precisely the status of vitamin D ( 43 ), and uncover its associations with athletic performance.…”