1211 www.smj.org.sa Saudi Med J 2011; Vol. 32 (11) Vitamin D levels in Saudi children with type 1 diabetes To the Editor I read with interest the paper by Bin-Abbas et al 1 on the Vitamin D levels in Saudi children with type 1 diabetes. In spite of afuent living condition, vitamin D (VD) defciency 2 and type 1 diabetes mellitus (T1DM) 3 are increasingly reported among Saudi children. Bin-Abbas et al 1 reported no correlation between glycemic control, measured by glycosylated hemoglobin (Hb A1c), and serum 25-hydroxy vitamin D (25OHD) level among the studied children with T1DM. However, various studies have shown a close correlation between serum 25OHD level and insulin efect. On one hand, insulin might have a stimulatory efect on the hepatic 25 hydroxylase activity, and hence, serum 25OHD level. 4 On the other hand, pancreatic tissue (more specifcally the insulin-producing beta-cells) as well as numerous cell types of the immune system express the VD receptor (VDR) and VD-binding protein. Also, some allelic variations in genes involved in VD metabolism and VDR are associated with glucose intolerance, insulin secretion, and sensitivity, as well as infammation. 5 Apart from modifying life styles and dietary habits, VD supplementation has been recently noticed to improve beta cell function and glycemic control in patients with T1DM who have VD defciency. 6 Mahmood D. Al-Mendalawi Department of Pediatrics Al-Kindy College of Medicine Baghdad University, Baghdad, Iraq Reply from the Author Although, some basic science researches reported a correlation between 25OHD level and insulin efect, however no clinical studies showed a correlation between 25OHD level and glycemic control in children with type 1 diabetes. Bassam Bin-Abbas Section of Pediatric Endocrinology Security Forces Hospital Riyadh, Saudi Arabia References 1. Bin-Abbas BS, Jabari MA, Issa SD, Al-Fares AH, Al-Muhsen S. Vitamin D levels in Saudi children with type 1 diabetes. Saudi Med J 2011; 32: 589-592. 2. Al-Atawi MS, Al-Alwan IA, Al-Mutair AN, Tamim HM, Al- Jurayyan NA. Epidemiology of nutritional rickets in children. Saudi J Kidney Dis Transpl 2009; 20: 260-265. 3. Abduljabbar MA, Aljubeh JM, Amalraj A, Cherian MP. Incidence trends of childhood type 1 diabetes in eastern Saudi Arabia. Saudi Med J 2010; 31: 413-418. 4. Colette C, Pares-Herbute N, Monnier L, Selam JL, Tomas N, Mirouze J. Efect of diferent insulin administration modalities on vitamin D metabolism of insulin-dependent diabetic patients. Horm Metab Res 1989; 21: 37-41. 5. Takiishi T, Gysemans C, Bouillon R, Mathieu C. Vitamin D and diabetes. Endocrinol Metab Clin North Am 2010; 39: 419- 446. 6. Aljabri KS, Bokhari SA, Khan MJ. Glycemic changes after vitamin D supplementation in patients with type 1 diabetes mellitus and vitamin D defciency. Ann Saudi Med 2010; 30: 454-458. Related topics Matthana MH. Te relation between Vitamin D defciency and fbromyalgia syndrome in women. Saudi Med J 2011; 32: 925-929. Asemi Z, Taghizadeh M, Sarahroodi S, Jazayeri S, Tabasi Z, Seyyedi F. Assessment of the relationship of vitamin D with serum antioxidant vitamins E and A and their defciencies in Iranian pregnant women. Saudi Med J 2010; 31: 1119-1123. Correspondence