ABSTRACT
OBJECTIVE: To assess urinary cotinine and the effects of smoking on 25(OH)D levels in 67 male smokers. MATERIAL AND METHOD: Urine and blood specimens were analyzed for cotinine and serum 25 hydroxyvitamin D (25(OH)D) concentrations by high performance liquid chromatography (HPLC) and chemiluminescent immunoassay, respectively. The accuracy, precision and detection limit of the HPLC method were also tested. RESULTS: The detection limit of urinary cotinine was 0.02 microg/ml. The recoveries of cotinine concentrations of 0.15-2.0 microg/ml were greater than 95%. Only 23.9% of smokers had sufficient levels of serum 25(OH)D at least 30 ng/ml. The smokers were divided into dairy co-operative smokers and other smokers. The average urinary cotinine concentrations of 1,421.42 and 1,866.52 microg/g creatinine were not significant different in dairy co-operative smokers and other smokers whereas the average 25(OH)D of 29.09 and 22.65 ng/ml, respectively, were significantly different at p-value of < 0.001. CONCLUSION: The 42.86% and 10.26% of the diary co-operative smokers and other smokers had sufficient serum 25(OH)D levels to prevent osteoporosis.
