Assessment of Vitamin D Status, its Determinants and Relationship with Bone Health in Indian Children and Young Adults with Type-1 Diabetes

Recent evidence suggests that vitamin D deficiency and type-1 diabetes (T1D) have a bidirectional cause–effect relationship. The objective of this study is to estimate the prevalence and determinants of vitamin D deficiency in Indian children and young adults with T1D and assess the relationship between vitamin D status and their bone health. It is a single-centre, cross-sectional study. Inclusion: Children, young adults aged 5–25 years with T1D duration >1 year. Exclusion: Already on vitamin D supplementation, conditions affecting bone health. Data collected: Demographic, clinical, anthropometry, biochemical, body composition, DXA, pQCT measurements. A total of 453 participants (251 girls) with T1D, mean age = 13.5 ± 4.0 years, disease duration = 5.7 ± 3.9 years. Mean 25-hydroxy vitamin D concentration of study group is 20.4 ± 11.3 ng/mL. One hundred and eleven (24.5%) were deficient in 25-hydroxy vitamin D, 141 (31.1%) were insufficient and 201 (44.4%) were sufficient. 25-Hydroxy vitamin D concentrations had significant negative correlation with BMI Z-score, diastolic blood pressure, fat percentage Z-score and positive correlation with physical activity, haemoglobin concentrations and trabecular density (P < 0.05). Risk of developing vitamin D deficiency and insufficiency was significantly lower in subjects with good/intermediate glycaemic control versus poor control (P = 0.008). Higher diastolic blood pressure and female gender were significant risk factors for development of vitamin D deficiency. Vitamin D deficiency has high prevalence in children and youth with T1D and has detrimental effect on bone geometry of these subjects. Weight reduction increased outdoor physical activity, good glycemic control are some modifiable factors that may prove useful in preventing vitamin D deficiency.