Vitamin D serum levels and vitamin D receptor FokI polymorphism on tuberculosis children in Palembang, Indonesia

Background Deficiency vitamin D and vitamin D receptor (VDR) polymorphism are strongly associated with the susceptibility of tuberculosis in four seasons countries. As a country with sufficient sunlight, the incidence of tuberculosis in Indonesia remains high. Objective To asses the association between vitamin D serum levels and VDR FokI polymorphisms with the incidence of tuberculosis in children at Palembang. Methods A case control study was conducted at Department of Child Health Mohammad Hoesin Hospital Palembang on November 2011 to April 2012. Group samples consisted of children with tuberculosis based on inclusion criteria. Vitamin D (1.25(OH)2D3/calcitriol) serum level was measured by using IDS 1,25-Dihydroxy Vitamin D EIA kit and VDR FokI polymorphism was identified through RFLP analysis. Results Sixty subjects was divided equally to case and control groups. The mean of calcitriol serum level in case group was lower compared to control which are 105.5 (SD 66.9) pmol/L versus 162.9 (SD 52.9) pmol/L (P=0.001). We found nine subjects with calcitriol deficiency, eight out of thirty in children with tuberculosis and one out of thirty in healthy contacts (OR 10.5; 95% CI 1.2 to 90.7) pmol/L. The incidence of VDR FokI polymorphism was 28 out of 30 in case group and 22 out of 30 in control group (OR 5,0; 95% CI 0,9 to 26,4). Conclusion Vitamin D (calcitriol) deficiency and lower serum level are associated with higher risk of tuberculosis in children at Palembang. Polymorphism FokI in VDR gene also contributes to the susceptibility of tuberculosis.