Bone Abstracts

Objectives: 1) To determine the prevalence of Vitamin D deficiency in children with newly diagnosed cancer; 2) Compare Vitamin D levels of children with and without cancer; 3) Evaluate race and sex differences in Vitamin D levels.

Methods: IRB approved retrospective review of medical records from our pediatric tertiary care center from 2011–2018. Inclusion criteria were serum 25-OH D within 3 months of oncology diagnosis and other non-oncology diagnoses. Exclusions were patients recieving supplemental Vitamin D, and diagnoses and medication use affecting Vitamin D status (e.g. Renal, malabsorption, anticonvulsants). Patients were grouped by race. Oncology patients were age-, race- and sex-matched with three non-oncology patients. Data was analyzed using two-sample t-test for normality, followed by Wilcoxon rank-sum test.

Results: 544 patients were included (136 oncology, 408 non-oncology). Mean age was 8.5 years (range 1 month - 19 years). Overall mean 25-OH D level was 22.4 ng/ml in oncology patients and 30.1 in non-oncology patients and was significantly different (P=<0.0001). Black patients had the lowest 25-OH D levels in children with both oncology and non-oncology diagnoses, followed by ‘other races’ (Asian & mixed). The Caucasian children had the best Vit D status, regardless of diagnosis. 22.4% of Caucasian children with cancer had sufficient (30 ng/ml or more) levels, 44.7% were insufficient, and 32.9% were deficient (<20 ng/ml). In contrast, in black oncology patients, 12% were sufficient, 24% were insufficient, and 64% were deficient. This is compared to the non-oncology patients: Caucasian children were 55.3% sufficient, 36.1% insufficient, and 8.6% deficient, and black children were 41.3% sufficient, 28% insufficient, and 30.7% deficient. For all three race categories, differences were seen between races and diagnoses (P=<0.01). Black children had the highest rate of deficient levels (64%) compared to the ‘other race’ category (38.5%) and Caucasian children (32.9%) There was no significant difference in Vit D levels in boys and girls.

Conclusion: Children with cancer have a higher incidence of Vit D deficiency at the time of diagnosis than their non-oncology peers. Physicians should be aware of this risk and consider Vit D testing as a standard practice for newly diagnosed children with cancer.

Disclosure: The authors declared no competing interests.