Ahmed T. El-Serafi, Wenyi Zheng, Ibrahim T. El-Serafi, Fadwa Benkessou and Moustapha Hassan
College of Medicine, University of Sharjah, UAE
Vitamin D is a mysterious molecule which has various roles in different tissues. As exposure to the sun is the main producer of this vitamin, it is not surprising that modern life style affects the vitamin level. Hereby we evaluated the level of vitamin D in patients undergoing the preconditioning regimen prior to stem cell transplantation with busulphan. The latter is a cytostatic drug that has a narrow therapeutic range and requires intensive monitoring. The correlation between vitamin D and busulphan accumulation in the body has never been described before. The level of Bu in plasma was determined in 51 patients by using HPLC/GC after drug extraction. The area under the curve was determined by measuring the plasma concentrations at different time points. Vitamin D was estimated using ELISA technique. Patients with low area under the curve for the drug had the highest level of the vitamin. This correlation was very clear in children less than 5 years old. Patients showed significant variations in the levels of vitamin D according to the underlying disease. The inverse relationship between the area under the curve and the vitamin level was clear in neuroblastoma while absent in thalassemia. We explain our results by the induction of liver enzymes by vitamin D which affects the drug metabolism. We recommend the evaluation of vitamin D before the administration of busulphan.