PTH and vitamin D deficiency: In the poststroke group compared to the rest of the cohort (Table 3), the mean serum PTH levels (+34.3%) and the incidence of SPTH (+15.8%) were significantly higher, although the mean serum 25(OH)D concentrations were similar, and the incidence of vitamin D insufficiency (<50 nmol/L) was even slightly lower (−13.7%, P = 0.044).