Low vitamin D diet prevents myelofibrosis in JAK2V617F Tg mice. (A-D) Blood cell counts (A; n = 9-15), plasma 1,25(OH)₂D₃ levels (B; n = 4), and silver staining in femur sections (C) of JAK2V617F Tg mice at 22 weeks old that were fed with a normal or low vitamin D diet after weaning. Pictures of the metaphysis were digitized to distinguish fibrosis (blue), trabecular bone (red), and hematopoietic area (yellow; C) and enumerated as the ratio of each area (D; n = 4-7). Scale bar, 50 μm. Representative pictures or combined data of at least 3 independent experiments are shown. Data are represented as mean plus or minus SEM. *P < .05, **P < .01, ***P < .001 (ANOVA).