Background: In this study, the prevalence of vitamin D deficiency was assessed in a group of children and adolescent patients with recent-onset type 1 diabetes mellitus (T1DM).
Methods: Fifty-three patients with age 8-18 years and duration of T1DM less than 8 weeks were recruited. A food frequency questionnaire (FFQ) was used to assess dietary vitamin D and calcium intake. Sunshine exposure was measured using a questionnaire to quantify the amount of time children spent in the sun and other sun-related habits, and a sun index score was generated. Serum 25(OH)D < 20 ng/ml was considered as vitamin D deficiency. Logistic regression was used to assess predictors of vitamin D deficiency.
Results: All patients were vitamin D deficient (77%) or insufficient (23%). In a logistic regression model, it was shown that the risk of being vitamin D deficient was significantly decreased by sunlight exposure ≥ 15 minutes during the weekends versus < 15 minutes (OR: 0.06, 95% CI: 0.01-0.75; P=0.029). In addition, vitamin D deficiency in boys was lower than girls in this model (OR: 0.164 [95% CI: 0.02-1.11]; P = 0.063).
Conclusion: Vitamin D deficiency is highly prevalent among children and adolescents with T1DM in Iran. Boys and children with ≥ 15 minutes sunlight exposure in weekends were less likely to be vitamin D deficient than girls and those with < 15 minutes sunlight exposure.