Stability of Folate and Vitamin B12 in Human Serum after Long-Term Storage: A Follow-Up after 13 Years.

Eugène H J M Jansen,Piet K Beekhof

doi:10.1155/2018/9834181

Abstract

In epidemiological and nutrition research, it is very important to evaluate the stability of biomarkers as function of both storage time and temperature. In this study, the stability of folate and vitamin B12 in human serum samples has been tested after long-term storage at −80°C up to 13 years. Serum samples of 16 individuals were used in this study. The concentration of folate and vitamin B12 has been determined at t=0 and at 1, 8, and 13 years after storage at −80°C. The folate concentrations in serum samples remained stable at −80°C. The concentration of vitamin B12 was decreasing during the time of the study to about 50%. The correlation of the folate and also of the vitamin B12 concentrations in the stored samples compared with the starting values was still good. Therefore, although the concentration of vitamin B12 decreased upon storage, reliable comparative analyses can still be performed.

Highlights

Folate and vitamin B12 are both vitamins from the one-carbon metabolism and serve as compounds that repair DNA and remethylate homocysteine [1,2,3].e folate status is associated with several chronic diseases with a large impact on public health [4]
Stability of Folate and Vitamin B12. e stability of both folate and vitamin B12 in human serum was followed during 13 years
For vitamin B12, an almost linear decrease was observed during the time period of storage. e mean level of vitamin B12 decreased from 100% to 85.6%, 62.2%, and 50.5% at time points 1, 8, and 13 years, respectively

Summary

Introduction

Folate and vitamin B12 are both vitamins from the one-carbon metabolism and serve as compounds that repair DNA and remethylate homocysteine [1,2,3]. In epidemiological and clinical research, these vitamins are often used to make risk assessments in prospective studies In these studies, often serum or plasma samples were used from biobanks which have been stored for several years and sometimes even for decades. Erefore, the assessment of the stability of these biomarkers during long-term storage is of great importance [11]. E measurements of folate and to a lower extend vitamin B12 are important biomarkers in clinical medicine and in epidemiologic studies. Both vitamins can be measured by a variety of methods, but the use of autoanalyzers have become common practice [12]. E stability of folate and vitamin B12 in serum samples was determined after a long-term storage of up to 13 years at −80°C

Materials and Methods

Results

Discussion