FIG 1.

25-OH D₃ concentrations in mouse serum. Six weeks after mice were fed a diet containing a low vitamin D concentration (vitamin D concentration under detection level), the serum 25-OH D₃ concentrations were significantly lower than in mice fed a diet containing normal amounts of vitamin D (1,500 IU/kg) (P < 0.0001). Each symbol represents the serum concentration of an individual mouse. The values for both mice with the lowest 25-OH D₃ values in the vitamin D-deficient group were below the limit of quantification. For statistical analysis, unpaired t test was used. ***, P < 0.001.