Vitamin D status among infants and children in Shanghai, China: A hospital-based study

Abstract

The variation in vitamin D status is still unclear. We aim to describe the vitamin D status among healthy infants and children in Shanghai (31° N latitude), one of the largest cities in China. We conducted a hospital-based, 2-year retrospective observational study and recruited children for health examination at the Tongren Hospital affiliated with Shanghai Jiao Tong University School of Medicine from January 2019 to December 2020. Serum 25-hydroxyvitamin D (25(OH)D) levels were measured using an enzyme-linked immunosorbent assay. A total of 6164 children aged 0–11 years were included. Of these, 94.4% of the serum 25(OH)D measurements at first assessment were within the range of 12–50 ng/mL. The median 25(OH)D level was 31.3 (IQR 25.6, 38.1) ng/mL, the percentages of 25(OH)D < 20 ng/mL and 25(OH)D < 30 ng/mL were 10.0% and 43.8%, respectively. Low vitamin D status (deficiency and insufficiency) differed significantly by age group (infants, toddlers, preschoolers, and schoolers) and seasonality (all p