Fig. 4
25(OH)D2 and 25 (OH) D3 area-under-the-curves from randomization to day-28 (AUC28) or day-56 (AUC56). Bars represent means and standard errors. a and b, study-1: participants were randomized to a single oral dose of 50,000 IU D2 (solid bars) or placebo (open bars). c and d, study-2: participants were randomized to a single oral dose of 50,000 IU D3 (solid bars) or placebo (open bars) four days after receiving a single oral dose of 50,000 IU D2. 25(OH)D2, 25-hydroxyvitamin D2. 25(OH)D3, 25-hydroxyvitamin D3. *, p < 0.001. **, p < 0.005