Endocrine Abstracts

Background: Low vitamin D levels have been linked to stunted growth, lower bone mineral density and health. Optimal levels of vitamin D are not adequately defined and guidance regarding supplementation is limited.

Aim: To identify vitamin D levels in a cohort of Caucasian children aged 0–16 years, and describe how preterm birth, obesity, age and malabsorptive conditions correlate with sub-optimal levels.

Methods: We obtained 368 25(OH)D test results conducted over 8 months from electronic records at Royal Cornwall Hospital. 314 results were screened for demographic and clinical factors, and vitamin D status. Vitamin D levels are defined as deficient at <25 nmol/l, insufficient between 25–50 nmol/l and sub-optimal between 50–75 nmol/l.

Results: Insufficient vitamin D levels or lower were identified in 40.46% of the cohort and 75.19% had sub-optimal levels or lower. The mean vitamin D level across the cohort was 58.27 nmol/l. Mean vitamin D levels were 70.41 nmol/l in children aged 0–4, 58.30 nmol/l in children aged 5–10 and 50.26 nmol/l in children aged 11–16 (P<0.0001). In overweight children, there was a weak negative correlation of −0.2 between BMI and vitamin D levels. 9.68% of children born preterm had vitamin D deficiency compared to 4.17% of children born at term. Optimal levels were found in 35.48% of preterm children and 24.31% of those born at term. There was no significant difference in insufficient or lower vitamin D levels between children with (36.98%) and without (43.27%) malabsorptive conditions.

Conclusions: The prevalence of insufficient and sub-optimal vitamin D levels was higher than previously reported. Our study found that adolescents and overweight children are at risk of sub-optimal or lower vitamin D levels. Supplementation with regular review could be extended to these groups.