Serum Vitamin D, Zinc Levels and the Relationship between them in Children and Adolescents

Abstract

Background: Along with vitamin D deficiency, a common global health problem in developed and developing countries, zinc deficiency also remains one of the most common micronutrient deficiencies-related public health problems in some parts of the world. Determination of vitamin D and Zn status is important for the growth, development, and health of school-age children, as well as their intellectual achievement and academic performance. In this study, we aimed to evaluate serum 25(OH)D and Zn levels and the relationship between them in a nationally representative sample of Turkish children and adolescents.

Methods: A total of 541 children and adolescents aged 1 - 16 years were included in our study whose vitamin D and zinc test levels were measured and who applied to the Basaksehir Cam and Sakura City Hospital Pediatric Outpatient Clinic. Cases were examined by dividing them into subgroups according to their vitamin D levels (≤ 15 ng/mL deficiency; 15 - 20 ng/mL insufficiency; ≥ 20 ng/mL sufficiency) and age (< 5 years preschool; 5 - 10 years middle childhood; 11 - 16 years adolescence).

Results: The levels of 25(OH)D were lower than 20 ng/mL in 33% of the children. There was deficiency in 80 (15%) and insufficiency in 99 (18%) cases. A statistically significant difference was found in 25(OH)D and Zn levels in groups separated by 25(OH)D level and age (p < 0.001). A positive significant correlation was found between serum 25(OH)D and Zn levels (r = 0.468; p < 0.001). A negative correlation was found between 25(OH) D levels and age (r = -0.261; p < 0.001) and body mass index (BMI) (r = -0.308; p < 0.001).

Conclusions: In our study, we found high levels of vitamin D deficiency and insufficiency and a significant positive correlation between serum 25(OH)D and Zn levels in the pediatric population. Based on this possible contribution, we think that providing vitamin D support to children of all ages, including adolescents, and thus improving zinc levels may be beneficial in protecting from diseases that lead to morbidity and mortality as a result of reducing the rate of growth and development retardation, regulating of bone development, and contributing to the development of the immune system.