Microsampling and vitamin analysis: a match made in heaven?

Promovendus/a: Liesl Heughebaert

Promotor(en): Prof. dr. Christophe Stove

This thesis investigated whether vitamin D, vitamin B9, and vitamin B1 can be reliably
quantified in dried blood microsamples, focusing on challenges like hematocrit (Hct) bias,
analyte stability, and applicability.
The first part of this work addressed Hct-related effects, a major issue in quantitative dried
blood microsampling. Ultraviolet-visible and near-infrared (NIR) spectroscopy were evaluated
and validated for the non-destructive Hct measurement from dried blood spots (DBS). NIR
spectroscopy was further adapted for the Hct-based determination from volumetric absorptive
microsampling (VAMS) devices, achieving good accuracy and precision despite the device’s
more complex geometry.
The second part focused on the dried blood microsampling-based analysis of vitamins. To
enable vitamin D status monitoring, analytical and clinical validation of a DBS-based method
for 25-hydroxyvitamin D confirmed feasibility and interpretability compared to plasma using
a Hct-based conversion approach. For vitamin B9, stability challenges were investigated across
five folate vitamers. For vitamin B1, large-scale thiamine status monitoring via capillary
VAMS in the Belgian National Food Consumption Survey proved feasible.
Overall, this work highlights the promise of microsampling for nutritional biomarker
monitoring. With further validation and accessibility, it could strengthen nutritional
epidemiology and public health.