Children with hemoglobin E/β‐thalassemia have a high risk of being vitamin D deficient even if they get abundant sun exposure: A study from thailand

Background Vitamin D is a key component in calcium homeostasis, bone mineralization and immune function, and people with a vitamin D deficiency may therefore be at higher risk of osteoporosis, osteopenia, delayed growth and fractures. Vitamin D deficiency is a known clinical complication of patients with β‐thalassemia major; however, as yet there are limited data on the vitamin D status of patients with Hb E/β‐thalassemia. Hb E/β‐thalassemia is characterized by a wide clinical heterogeneity ranging from non‐transfusion dependency to transfusion dependency. Because patients with Hb E/β‐thalassemia are so clinically diverse, the prevalence of vitamin D deficiency might differ among Hb E/β‐thalassemia patients. Procedure We investigated the vitamin D status of 109 children with Hb E/β‐thalassemia who attended the Pediatric Hematology Clinic at the Siriraj Hospital in Bangkok, Thailand, from April 2009 to March 2010. Results Forty‐nine of the children were classified as transfusion‐dependent (TD) and the remainder (n = 60) as non‐transfusion‐dependent (NTD). Only 10.1% of the children in our study had normal vitamin D levels, despite Thailand's geographic position 15° N and 100° E and climate, which provides abundant sunlight exposure and therefore efficient vitamin D synthesis. In addition, NTD children were significantly more likely to be vitamin D deficient than TD children ( P  = 0.01). Conclusions Our results highlight the importance of monitoring serum vitamin D levels in children with Hb E/β‐thalassemia regardless of their clinical severity or the amount of sunlight they are exposed to. Pediatr Blood Cancer 2013;60:1683–1688. © 2013 Wiley Periodicals, Inc.