Vitamin D and Parathyroid Hormone in Pediatric Obesity

Suboptimal vitamin D status and high levels of parathyroid hormone are a common feature in the pediatric population with severe obesity, suggests the findings of a new study. Further, in these patients, the seasonal variations in 25(OH)D were not modified, and parathyroid hormone levels remained increased throughout the year, but without any seasonal variations. The findings have recently been published in the European Journal of Pediatrics.

Though obesity has been associated with lower 25(OH)D and higher PTH levels, the relation among vitamin D and PTH through a natural year in children with obesity is partially known to date.

The objective of this study was to analyze the prevalence of hypovitaminosis D in children with severe obesity. The researchers hypothesized that severe obesity could modify the seasonal variations in 25(OH)D and PTH serum levels throughout the year.

The study design consisted of a cross-sectional clinical and blood testing (calcium, phosphorus, 25(OH)D, and PTH) was carried out in 282 patients with severe obesity, aged 7.2–15.2 years. A control group was recruited (348 healthy children, aged 7.1–14.9 years). The criteria of the US Endocrine Society were used for the definition of hypovitaminosis D.

On data analysis, the following facts emerged:

• Vitamin D deficiency and hyperparathyroidism were more frequent (p < 0.05) in the obesity group (44.5% vs. 11.5% and 22.4% vs. 3.9%, respectively).
• There were seasonal variations in 25(OH)D levels in the obesity group, but they were lower (p < 0.05) with respect to the control group.
• In contrast, PTH levels were higher (p < 0.05) in the obesity group with respect to the control group, but there were no significant seasonal variations in PTH levels.

"Parathyroid hormone levels in obesity are independent of vitamin D status and do not appear to represent secondary hyperparathyroidism," wrote the team.

For the full article, follow the link: https://doi.org/10.1007/s00431-020-03857-4

Primary source: European Journal of Pediatrics