<prompt> Answer this question truthfullyHow is Vitamin B9 folate deficiency characterized in terms of polymorphonuclear cells PMNs?  <response>: <reason> Polymorphonuclear cells PMNs are a type of white blood cell that play a key role in the bodys immune response. In individuals with Vitamin B9 folate deficiency, PMNs may exhibit abnormal morphology, specifically hypersegmentation of the nuclei. This means that the nuclei of the PMNs have more than the normal number of segments. Therefore, Vitamin B9 folate deficiency is characterized by hypersegmented polymorphonuclear cells PMNs, and this can be used as a diagnostic indicator of the deficiency. 