Vitamin A deficiency remains a major public health problem worldwide, particularly among young children. Capillary blood has the potential for application in vitamin A assessment. The aim of this study is to validate the accuracy of capillary blood for assessing vitamin A nutritional status among young children. Venous and capillary blood samples were simultaneously collected from 1366 healthy children under 7 years of age across 12 regions in China. Retinol was measured using high-performance…
