Fig. 17
Predicted effects of probiotic supplementation on 25(OH)D and its metabolites with age. The predicted concentrations of (a) extracellular 25(OH)D, (b) extracellular 1,25(OH)2D, (c) intracellular 25(OH)D, (d) intracellular 1,25(OH)2D and (e) the VDR:1,25(OH)2D complex with age, from solving Eqs. (3)–(23) with baseline parameters given in Tables 1, 2 and 3 and age functions given in Figs. 2, 3, 4 and 5. Solid lines represent baseline values of vitamin D intake \(D^{0}=4.8\) and \(D^{1}=0.5\) nmol/L day−1 and dashed lines \(D^{0}=3.2\) and \(D^{1}=0.35\) nmol/L day−1. A constant daily intervention of probiotics \(\mathrm {5\times 10}^{9}\) CFU/day is administered from day 0 to day 200 to individuals aged 20 (blue), 40 (red), 60 (green) and 80 (orange) years.
