Vitamin D Deficiency in Childhood Cancer Survivors: Results from Southern Thailand.

There is limited information on vitamin D deficiency among childhood cancer survivors (CSS), especially in tropical countries. The aims of this study are to determine the prevalence and risk factors for vitamin D deficiency in CCSs. This study was conducted at the long-term follow-up clinic for CCSs at Prince of Songkla University, Songkhla, Thailand. All CCSs who were followed up between January 2021 and March 2022 were enrolled. Demographic data, dietary dairy intake, average weekly duration of outdoor activities, total 25-hydroxyvitamin D [25(OH)D] levels, parathyroid hormone levels, and blood chemistry were collected. A total of 206 CCSs with a mean age at follow-up of 10.8 ± 4.7 years were included. The prevalence of vitamin D deficiency was 35.9%. Female gender (odds ratio (OR): 2.11, 95% CI: 1.08-4.13), obesity (OR: 2.01, 95% CI: 1.00-4.04), lack of outdoor activities (OR: 4.14, 95% CI: 2.08-8.21), and lower dietary dairy intake (OR: 0.59, 95% CI: 0.44-0.80) were independent risk factors for vitamin D deficiency. Vitamin D deficiency was common in CCSs and associated with female gender, obesity, lack of outdoor activities, and lower dietary dairy intake. Regular 25(OH)D screening should be established in long-term care to identify those who require vitamin D supplements.