https://www.selleckchem.com/products/heparan-sulfate.html Altogether, combined use of serum CK 18, Tg, and CEA may be a promising biomarker in screening benign and malignant thyroid tumors. Altogether, combined use of serum CK 18, Tg, and CEA may be a promising biomarker in screening benign and malignant thyroid tumors. Host factors related to failure of eradication of Helicobacter pylori (H. pylori) are increasingly studied. This work aimed to study the influence of 25-hydroxy-vitamin D [25(OH)-vitD] status on the rate of H. pylori eradication. One hundred and fifty patients infected with H. pylori were tested for serum 25(OH)-vitD level prior to 14 days clarithromycin-based triple eradication therapy. Accordingly, patients were divided into group I (eradication successful) and group II (eradication failure). Both groups were compared regarding mean level of serum 25(OH)-vitD and number and percentage of patients with deficient 25 (OH)-vitD. Overall rate of eradication was 72%. Mean serum level of 25(OH)-vitD was higher in the eradication successful group compared to the group of eradication failure (28.12 ± 8.10 vs. 13.54 ± 6.37; p < 0.001). The percentage of patients with 25(OH)-vitD deficiency was higher in the group of eradication failure compared to the group of successful eradication [30 (71.5%) vs. 19 (17.5%); p < 0.001]. Patients with sufficient 25(OH)-vitD had a higher rate of eradication compared to patients with deficient 25(OH)-vitD (88% vs. 38.5%). This study suggested that deficiency of 25(OH)-vitD could be a risk factor for H. pylori eradication failure, and it recommends to investigate the effect of vitamin D supplementation on H. pylori eradication. This study suggested that deficiency of 25(OH)-vitD could be a risk factor for H. pylori eradication failure, and it recommends to investigate the effect of vitamin D supplementation on H. pylori eradication. Most errors in the laboratory occur due to processes related to the pre-analytical phase. The p