Seasonal Changes in Vitamin D Levels of Healthy Children in Mid-Latitude, Asian Urban Area
10.5223/pghn.2021.24.2.207
- Author:
Jong Woo WON
1
;
Seong Kwan JUNG
;
In Ah JUNG
;
Yoon LEE
Author Information
1. Department of Pediatrics, Korea University Medical Center, Seoul, Korea
- Publication Type:Original Article
- From:Pediatric Gastroenterology, Hepatology & Nutrition
2021;24(2):207-217
- CountryRepublic of Korea
- Language:English
-
Abstract:
Purpose:This study aimed to investigate the seasonal changes in vitamin D levels in a healthy pediatric population living in mid-latitude East Asian urban areas.
Methods:A pediatric population was selected from single secondary hospital visitors.Clinical data and serum vitamin D levels were collected retrospectively. Statistical analyses were performed based on the month of the blood sampling date, subject age, and vitamin D supplementation history. The data were categorized into three subgroups based on serum vitamin D levels—adequate (≥30 ng/mL), insufficient (20–29 ng/mL), and deficient (<20 ng/mL).
Results:Of the 481 patients, 172 had vitamin D supplementation history. More than 70% of the total study population had inadequate vitamin D levels (<30 ng/mL). The non-supplemented group and the supplemented group showed significantly uneven monthly distribution of the adequate, insufficient, and deficient subgroups. Only the nonsupplemented group showed significantly different average vitamin D levels in the summer months compared to the winter months. In the non-supplemented group, vitamin D levels were the lowest in March, the highest in August and September. Significant relevance was noted between vitamin D supplementation status and vitamin D serum level in February and March. There was no significant difference between different age groups in terms of the distribution of vitamin D levels.
Conclusion:Currently-widespread vitamin D replacement methods seem to have some effect on increasing the overall serum vitamin D levels, specifically during late winter when natural serum vitamin D levels plunge. However, they are unable to fully compensate the seasonal fluctuation.
