Stability of blood (pro)vitamins during four years of storage at -20 degrees C: consequences for epidemiologic research.

Author(s): Ockè MC, Schrijver J, Obermann-de Boer GL, Bloemberg BP, Haenen GR, Kromhout D

Publication: J Clin Epidemiol, 1995, Vol. 48, Page 1077-85

PubMed ID: 7775995 PubMed Review Paper? No

Purpose of Paper

Conclusion of Paper

Studies

1. Study Purpose

   The purpose of this study was to determine the effects of storage for up to 4 years at -20 degrees C on levels of vitamins in EDTA-plasma and whole blood. EDTA-whole blood was collected from donors, stored overnight and transported at 4 degrees C. Whole blood and plasma were aliquoted, and most aliquots were transported at -70 degrees C and then subsequently stored at -20 degrees C while some were analyzed prior to freezing (24-48 h after collection).

   Summary of Findings:

   Significantly lower mean vitamin A, beta-carotene, vitamin E, and folic acid levels were found in EDTA-plasma stored at -20 degrees C for 3 months than in refrigerated plasma, and levels continued to decline progressively with further storage. Total carotenoid levels also declined with increasing storage duration. A significant decline in total carotenoid levels was observed in plasma stored at -20 degrees C for 6 months or more compared to levels measured in refrigerated plasma. Niacin levels were slightly higher in whole blood stored frozen for 6 months than in refrigerated whole blood, but levels were significantly lower after 48 months and not significantly different from values in refrigerated plasma when stored for 12-36 months. Vitamins B1 and B2 in whole blood and vitamins D, B6 and B12 in EDTA-plasma showed significant changes in levels after storage compared to refrigerated specimens, but the effects were inconsistent and did not display clear trends.

   Biospecimens

   • Bodily Fluid - Blood
   • Bodily Fluid - Plasma

   Preservative Types

   • Frozen
   • Other Preservative

   Diagnoses:

   • Normal

   Platform:

   Analyte	Technology Platform
   Small molecule	HPLC
   Small molecule	Radioassay

   Pre-analytical Factors:

   Classification	Pre-analytical Factor	Value(s)
   Storage	Storage duration	24-48 h 3 months 6 months 12 months 24 months 36 months 48 months
   Biospecimen Preservation	Type of fixation/preservation	Frozen Refrigeration
   Biospecimen Aliquots and Components	Blood and blood products	Plasma Whole blood

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