PTH and myeloid sarcoma: In addition, because PTH and FGF23 also regulate extra-renal 1-alpha hydroxylase in innate and adaptive immune cells, (for example see Ref Bacchetta et al. 2013) this dysequilibrium has the potential to modify immune-inflammatory processes in MS via autocrine as well as endocrine vitamin D metabolism, in keeping with evidence that impaired vitamin D nutrition is associated with MS (Pierrot-Deseilligny and Souberbielle 2017; Munger et al. 2006; van der Mei et al. 2007; Simpson Jr et al. 2010).