Vitamin D status positively associates with interleukin‐6 and tumour necrosis factor alpha in healthy young children (40.8)

Abstract

Vitamin D status associates with immune function and duration of illness. The objective was to examine interleukin‐6 (IL‐6) and tumor necrosis factor alpha (TNF) in relation to vitamin D status in healthy children. Children (n=457; 1.8‐5.8 y) were recruited from randomly selected daycares in Montreal. Body mass index Z‐scores for age (BAZ) were calculated using the WHO growth standard. Capillary plasma samples were measured for IL‐6, TNF and C‐related peptide (CRP) (Multiplex assays; Millipore Corp. USA); CRP values > 10 mg/L were excluded. Vitamin D status (chemiluminescence; Liaison, Diasorin Inc.) was categorized using plasma 25‐hydroxyvitamin D (25(OH)D) values <50.0 nmol/L (low; n=52), 50.0‐74.9 nmol/L (adequate; n=189) and 蠅75.0 nmol/L (robust; n=216). Differences among vitamin D status categories were tested using mixed model ANOVA (random effects: age, sex, BMI Z‐score and season) and Tukey’s post hoc test; data are mean ± SD. Average age was 3.7 ± 1.0 y, BAZ 0.5 ± 1.0 kg/m2 and CRP 0.9 ± 1.6 mg/L. By design all pair‐wise differences in 25(OH)D (nmol/L) were observed (low: 40.8 ± 6.7; adequate: 63.4 ± 7.6; robust 100.3 ± 22.4, P<0.001). Highest IL‐6 (low: 9.9 ± 13.0; adequate 9.9 ± 12.9; robust 14.0 ± 14.9 ng/L, P<0.02) and TNF (low: 6.8 ± 3.5; adequate 7.1 ± 3.1; robust 7.8 ± 3.4 ng/L, P<0.03) were observed in the robust group. The data suggests that robust vitamin D status supports innate immune function.Grant Funding Source: Supported by Dairy Farmers of Canada