The "Supporting information" as a whole file contains two tables and one figure.

They are listed separately as follows: S1 Fig. The distribution of 25-hydroxyvitamin D3 in different Group of C-peptide. The y-axis represents the levels of 25-hydroxyvitamin D3. The different modes of bars represent different C-peptide groups. The error bars represent the standard deviation. S1 Table: The measurement of Skeletal muscle mass, muscle strength, and somatic function. The first column of the table lists the names of the test indicators, and the second column lists the corresponding test methods and procedures. S2 Table: The description of missing data. The first column represents variable names, the second and third columns represent the number of missing and non-missing samples, respectively, and the fourth column represents the proportion of missing values. (DOCX)