Association between vitamin D deficiency and myopia severity among school-aged children in Indonesia

The majority of myopia cases worldwide occur in developing countries. In Indonesia, the prevalence of refractive disorders among school-aged children (5–19 years) is estimated to be around ±10% of 66 million children. Vitamin D plays a significant role in maintaining the flexibility of the ciliary ring in the eye, which is essential for proper lens stretching during growth. This flexibility helps prevent and delay the onset of myopia. Deficiency in vitamin D may lead to changes in calcium levels intracellularly, potentially disrupting the contraction and relaxation of the ciliary muscle, which may result in the development of myopia. This study was an analytic observational study with a cross-sectional approach. The sample in this study consisted of students with myopia from Darul Ihsan Islamic Boarding School, selected using the consecutive sampling method. Visual acuity was assessed by utilizing a Snellen chart, and vitamin D3 levels were evaluated with an enzyme-linked immunosorbent assay (ELISA) test. The study included a majority of female participants (26 subjects, 52%), with a median age of 13 years. Most of the students had mild myopia (29 subjects, 58%), followed by moderate myopia (15 subjects, 30%) and severe myopia (6 subjects, 12%). The mean vitamin D3 level among the subjects was 40.32 ± 20.99 nmol/L. This study highlighted significant differences between vitamin D3 levels and each degree of myopia in students at Darul Ihsan Islamic Boarding School. The findings conclude that lower vitamin D3 levels are a risk factor for the development of myopia.