Dried blood microsample-assisted determination of vitamins: Recent developments and challenges

Abstract

Although vitamin deficiencies are a well-known issue, monitoring of the vitamin status and diagnosis of vitamin deficiencies in remote regions is a complicated task. Dried blood microsampling, as an alternative sampling strategy, could offer a solution to the several drawbacks related to conventional venipuncture.Although highly relevant, the number of microsampling procedures that has been developed for assessing vitamins in dried blood samples is rather limited, indicating the challenging nature of the subject. This review discusses several challenges inherent to vitamin analysis in microsamples, thereby covering topics including sampling strategy, hematocrit (Hct) effect, sample preparation, calibration, assay sensitivity, stability, and clinical interpretation of the results.

Patient-Centric Assessment of Thiamine Status in Dried Blood Volumetric Absorptive Microsamples Using LC–MS/MS Analysis

“…Currently, the diagnosis of thiamine deficiency in remote and resource-limited regions is hampered due to several drawbacks related to traditional venous blood collection, for example, the need for trained personnel, cold chain transport, and so forth. Fortunately, microsampling strategies have shown their usefulness for sampling in developing countries, mainly in terms of ease of sample collection and storage …”

“…Furthermore, venipuncture often causes anxiety in patients, especially in pediatrics. Therefore, there is an increased interest in minimally invasive methods, allowing the collection of small volumes of blood, to monitor the nutritional thiamine status in developing countries. , Currently, two dried blood spot (DBS)-based methods have been described for the determination of TDP. , Both methods use HPLC-fluorescence detection to quantify TDP levels in dried blood microsamples. Fluorescence detection requires pre-column derivatization of TDP, which involves the handling of noxious agents and implies an extra step in the sample preparation procedure.…”

“…Thereby, the VAMS devices overcome a well-known issue in DBS sampling, which is the Hct-based area bias. − Moreover, VAMS overcomes the need to handle micropipettes and accurate pipetting of small volumes, which is more convenient in the context of self-sampling and the set-up of large epidemiological studies . Furthermore, VAMS simplifies sample storage and transport, which is especially interesting for analytes suffering from stability issues, such as TDP. , …”

“…Therefore, there is an increased interest in minimally invasive methods, allowing the collection of small volumes of blood, to monitor the nutritional thiamine status in developing countries. 2,17 Currently, two dried blood spot (DBS)-based methods have been described for the determination of TDP. 18,19 Both methods use HPLC-fluorescence detection to quantify TDP levels in dried blood microsamples.…”

Delayed Processing of Chilled Whole Blood for 24 Hours Does Not Affect the Concentration of the Majority of Micronutrient Status Biomarkers

“…The collection and use of capillary blood samples such as dried blood spots (DBS) for micronutrient biomarker analysis negates some of the limitations of venous blood sampling and can simplify sample transport logistics. DBS methods have been published for a limited number of micronutrient biomarkers [reviewed by Verstraete et al ( 6 )] and have been applied in a number of studies for vitamin A (retinol-binding protein) ( 7 , 8 ) and vitamin D ( 9 , 10 ). However, venous blood samples remain the biological sample of choice to ensure reliable, precise, and accurate assessments of micronutrient statuses, using reference methods with established cutoffs for deficiency ( 2 ).…”