Table 2.
Baseline demographic and clinical characteristics associated with vitamin D concentrations.
| Categorical variables | ||||
|---|---|---|---|---|
| Variable | Level | n | Vitamin D (nmol/L) | P |
| Month of sampling | Non-summer | 849 | 38.0 (27.0–54.0) | <.001 |
| Summera | 258 | 51.0 (39.0–65.0) | ||
| Ethnicity | South Asian | 41 | 30.0 (22.0–44.0) | .001 |
| White/Others | 1066 | 42.0 (30.0–58.0) | ||
| Pretreatment vitamin D supplementation | No | 861 | 39.0 (28.0–55.0) | <.001 |
| Yes | 246 | 50.0 (36.0–64.0) | ||
| Drug | Infliximab | 659 | 39.0 (29.0–56.0) | .021 |
| Adalimumab | 448 | 44.0 (31.0–59.0) | ||
| Continuous variables | ||||
|---|---|---|---|---|
| Variable | Spearman’s rho (R) | P | ||
| Serum albumin | 0.18 | <.001 | ||
| Harvey Bradshaw Index | −0.07 | .040 | ||
| Short pediatric Crohn’s disease activity index | −0.33 | .003 | ||
| CRPb | −0.12 | <.001 | ||
| Fecal calprotectinb | −0.11 | .003 | ||
| Hemoglobin | 0.10 | .002 | ||
aSampling during the summer was defined as a blood sample obtained for vitamin D analysis in the months of June, July, and August.
bVariables were log-transformed for analysis.
Abbreviation: CRP, C-reactive protein.