Tabriz University of Medical Sciences Health Promotion Perspectives 2228-6497 2 2 2012 12 31 Validation of the Use of Dried Blood Spot (DBS) Method to Assess Vitamin A Status 180 189 10.5681/hpp.2012.021 EN Elham Fallah Seyed Hadi Peighambardoust Journal Article 10.5681/hpp.2012.021 2012 04 11 Background: Vitamin A deficiency is an important dietary deficiency in the world. Thus, the necessity of screening for deficient populations is obvious. This paper introduces a fast, cheap and relatively reliable method called "dried blood spot" (DBS) method in screening the deficient populations. The validity of this method for retinol measurement was investigated. Method: The "precision" and "agreement" criteria of the DBS method were assessed. The precision was calculated and compared with those of plasma using F-test. The agreement was evaluated using Bland-Altman plot. Results: The imprecision of retinol measurements in dried spots was not significantly different from those of the control (plasma). A good correlation coefficient (r2=0.78) was obtained for dried spots’ retinol measurements versus plasma’s retinol analysis (P < 0.01). Paired t-test showed no significant difference between the DBS and retinol methods on a group level. Imprecision of DBS measurement was acceptable, compared to that of the plasma method. The difference between these two methods was not statistically significant on a group level. Conclusion: Application of DBS standard samples, in which a part of the plasma was replaced with the artificial plasma, was shown to be a reliable calibration mean for retinol measurements in DBS samples. Retinol in dried spots was stable for 90 days. Overall, the DBS method provided a precise measurement of retinol, showing results that were comparable with the measurement of retinol in plasma.