Relationship of circulating levels of 25(OH)D with parathyroid hormone in various stages of chronic kidney disease

Introduction: vitamin d deficiency is common in both general population and chronic kidney disease (ckd) patients.objectives: the aim of this study was to compare 25(oh)d3 levels in stages 2 to 5 of ckd patients and to evaluate whether inactive vitamin d supplement could prevent increasing of serum pth levels.patients and methods: a total of 58 stages 2-4 ckd and 57 stage 5 ckd hemodialysis (hd) patients who had 25(oh)d3 <30 ng/ml were considered. all cases were under appropriate treatment for preventing secondary hyperparathyroidism. at the beginning, serum levels of vitamin d3, intact parathyroid hormone (ipth), calcium (ca), phosphate (p), alkaline phosphate (alp) and albumin were measured. patients received 300 000 iu/im vitamin d3 and after 2 months this dosage was repeated, if it was necessary. all biochemical markers were checked and the effect of vitamin d3 was evaluated.results: at base line, serum levels of 25(oh)d3 and pth in patients with stages 2 to 5 of ckd were; 14.85±7.8 ng/ml (stage 2), 70.8 ± 16.8 pg/ml (stage 2); 16.48 ± 7.8 ng/ml (stage 3), 69.6 ± 39.2 pg/ml (stage 3); 16.33 ± 8.1 ng/ml (stage 4), 123.74 ± 92.5 pg/ml (stage 4); and 13.86 ± 6.5 ng/ml (stage 5) and 567.23 ± 276.7 pg/ml (stage 5), respectively.two months after injections, 25(oh)d3 and pth were changed as follow; 28.62 ng/ml (p = 0.001) (stage 2), 59.38 pg/ml (p = 0.34) (stage 2); 37.79 ng/ml (p < 0.001) (stage 3), 62.41 pg/ml (p = 0.18) (stage 3); 31.14 ng/ml (p = 0.001) (stage 4), 91.02 ± 69.4 pg/ml (p = 0.003) (stage 4) and 48.48 ng/ml (p < 0.001) (stage 5) and also 282.77 pg/ml (p < 0.001) (stage 5), respectively.conclusion: the result of this study showed the vitamin d3 levels increased in all stages after 2 months. also, the findings indicated that administration of vitamin d3 in all patients of the study groups reduced serum pth levels. however, the rate of reduction was higher in stages 4 and 5 of ckd as compared to stages 2 and 3 of ckd (p < 0.001).this result encourages us to prescribe supplement vitamin d3 if the level is less than 30 ng/ml.