Endocrine Abstracts

Background: 25-hydroxycholecalciferol (25(OH)D) deficiency is prevalent in the Scottish paediatric population. Paediatric oncology patients are at even higher risk of becoming deficient because they spend more time indoor, often have an inadequate dietary intake and increased 25(OH)D catabolism during treatment. We aimed to assess 25(OH)D and parathyroid hormone (PTH) levels before and after supplementation in Scottish children with cancer.

Methods: Plasma 25(OH)D and PTH were measured twice in patients aged <18 years, diagnosed and treated for cancer. Supplementation was prescribed according to UK guidelines, and consisted of macronutrient (enteral, +/− parenteral nutrition) and micronutrient (vitamin D, multivitamins, +/− macronutrient). 25(OH)D and PTH ranges were classified according to the Scottish laboratory reference; 25(OH)D: suboptimal (50–75 nmol/l), insufficient (25–50 nmol/l) and deficient (<25 nmol/l) and PTH: 1.6–7.5 pmol/l. Descriptive statistics, Spearman’s and Wilcoxon’s test were performed.

Results: 40 patients had plasma 25(OH)D and PTH available before and after supplementation. Median (IQR) time between diagnosis and supplementation was 0.29 (0.2–0.7) years. At baseline, plasma 25(OH)D was suboptimal in 23% of patients and below suboptimal in 62.5%. 7.5% had hyperparathyroidism and 12.5% hypoparathyroidism. 17.5% received macronutrient supplementation. Of these 43% remained with plasma 25(OH)D below suboptimal and 7% with high PTH. Median (IQR) 25(OH)D decreased from 77 (42–81) to 54 (19–89) nmol/l and PTH increased from 3.6 (1.45–5.75) to 4.3 (1.45–7.15) pmol/l. Conversely, those supplemented with micronutrients (82.5%) had a significant improvement in 25(OH)D (P<0.001; r −0.7); median (IQR) increased from 26.5 (15–37) to 65.5 (44–87) nmol/l; yet 20% remained below suboptimal levels. Median (IQR) PTH decreased from 3.3 (2.3–5) to 3 (2–4.4) pmol/l (P>0.5). 25(OH)D and PTH did not significantly correlate (P>0.05).

Conclusion: 25(OH)D deficiency was highly prevalent, only improving following micronutrient supplementation. To optimise the 25(OH)D status, regular monitoring alongside appropriate supplementation, which must be adapted to the specific needs of this population, should be incorporated into clinical practice.