Retinol concentrations in capillary dried blood spots from healthy volunteers: method validation

Abstract

Background: Vitamin A deficiency (VAD) is a major public health problem in the developing world, leading to > 3 million eye-related problems in preschool children. Nearly 250 million children have subclinical VAD, resulting in a 23% increase in childhood mortality. Difficulties in obtaining samples to assess VAD have hampered the detection, intervention, and surveillance of VAD. The use of dried blood spots (DBS) could ameliorate many problems of vitamin A assessment. Objective: The objective of this study was to validate the use of retinol in DBS for vitamin A assessment by comparing it with venous and capillary serum retinol. Design: Venous and capillary blood specimens were obtained simultaneously from 20 healthy adult volunteers. From each blood specimen, both DBS and liquid serum were prepared (a total of 80 samples). All specimens were maintained at Ϫ70 ЊC until HPLC analysis. Results: The mean retinol concentrations in the 4 sample types were as follows: venous serum (2.02 ± 0.42 mol/L, or 58 ± 12 g/dL), capillary serum (2.06 ± 0.42 mol/L, or 59 ± 12 g/dL), venous DBS (2.06 ± 0.49 mol/L, or 59 ± 14 g/dL), and capillary DBS (2.09 ± 0.45 mol/L, or 60 ± 13 g/dL). Of the 6 possible 2-way combinations, the R 2 values ranged from 0.77 for capillary DBS versus venous DBS to 0.95 for venous serum versus capillary serum. Conclusions: DBS retinol measured by HPLC is comparable with serum retinol. Thus, it is possible to compare and combine blood retinol concentration data obtained from DBS with current and historic measurements in serum.

Retinoids and Pulmonary Hypertension

“…Furthermore, our patient samples were obtained from central veins (via the introducing catheter), whereas the samples from normal control subjects were taken from peripheral veins. However, Craft et al 35 have reported no differences in retinol levels between venous and capillary serum samples. Also, short of experiments demonstrating that manipulations of ATRA or GADD45A in experimental models or in clinical trials affect the severity or outcomes of pulmonary hypertension, we acknowledge that we have not established pathophysiological roles for these agents.…”

Ferritin concentrations in dried serum spots from capillary and venous blood in children in Sri Lanka: a validation study

“…Novel approaches, such as analyzing ferritin from serum or plasma samples that are spotted and dried on filter paper, were reported to yield accurate and reliable results (7)(8)(9). Recently, assessment of vitamin A status on the basis of serum retinol measurement from capillary-blood spot samples was also reported (12). Because the spot ferritin methods had not been previously evaluated in field settings and were established by using serum or plasma obtained from venous blood, we conducted the present study to evaluate the accuracy of a spot ferritin method (7) that uses DSS samples obtained from venous and capillary blood in school-aged children living in Colombo, Sri Lanka.…”

Prevalence of anaemia, deficiencies of iron and vitamin A and their determinants in rural women and young children: a cross-sectional study in Kalalé district of northern Benin

“…Anaemia was defined according to WHO standards as Hb below 11 mg/dl for children aged 6 months to 5 years and below 12 mg/dl for non-pregnant women (26) . Subclinical inflammation was defined as CRP > 5 mg/l and/or AGP > 1 g/l.…”