Fig. 1

Locally weighted scatterplot smoothing (LOWESS) curve analysis of the relationship between vitamin D status and severity of illness scores. DCCI = Deyo-Charlson Comorbidity Index; 25OHD = 25-hydroxyvitamin D; APACHE II = Acute Physiology and Chronic Health Evaluation II. LOWESS curve analysis demonstrates a steep, near inverse, relationship between DCCI (a) as well as APACHE II (b) and 25OHD levels from 0 to 10 ng/mL. Beyond 25OHD levels of 10, there is progressive flattening of the curve