Abstract: The invention relates to assay or determining intercellular niacin status in solid tissues. One extracts intracellular pyredine nucleotides, cycles these, in the presence of agents which reduce the pyredine nucleotides and a dye, which reflect the change. Changes in absorbance of the dye molecule permit determination of the niacin status.
Abstract: The present invention is a novel and rapid assay for intracellular niacin status in a biological sample that is both highly sensitive and accurate over a wide range of niacin status. The assay can be performed directly on a biological sample such as blood and is useful for determining the niacin status in a subject such as a human. In a preferred form, the assay is incorporated into a kit or an apparatus for the rapid and accurate determination of niacin status in a subject.