Fig. 1

The adjusted dose-response associations between serum concentration of vitamin B12 and risk of all-cause mortality among the whole population, male and female, based on model 4. Serum concentration of vitamin B12 was modeled via a restricted cubic spline function with knots being set at 10th, 50th, and 90th percentiles of its distribution. The reference value was set at 450 ng/mL. The five vertical reference lines were used to denote the 10th (203 ng/mL), 25th (260 ng/mL), 50th (371 ng/mL), 75th (542 ng/mL), and 90th (740 ng/mL) percentiles of serum concentration of vitamin B12 among the whole population