Endocrine Abstracts

Secondary hyperparathyroidism (SHPT) as well as vitamin D deficiency are highly prevalent in patients with chronic kidney disease (CKD). Traditional therapy of SHPT includes administration of calcitriol, mainly in dialysis patients. Data about effects of native vitamin D repletion in such patients are still inconsistent. The aim was to assess effects of vitamin D repletion in CKD patients with SHPT and vitamin D deficiency. 88 patients, mean age 50.8±14.6 years with CKD 3–5 stages, SHPT (PTH>65 pg/ml) and vitamin D deficiency (25OHD <20 ng/ml) were divided in 2 groups. 1^st group (48 patients) received cholecalciferol 2000–3000 IU daily during 6 months, 2^nd group (40 patients) do not receive vitamin D compounds. Initially and after 6 months of follow-up serum parathormone (PTH), 25OH-vitamin D (25OHD), creatinine, calcium and phosphorus were measured, estimated glomerular filtration rate (eGFR) was calculated by MDRD formula. In the cholecalciferol group after 6 months of observation mean 25OHD level significantly increase from 10.7±6.1 to 23.0±11.5 ng/ml, P<0.0001; PTH decrease from 207.7±123.2 to 156.9±103.0 pg/ml, P=0.052. 25OHD level >30 ng/ml was reached in 25% of patients, target PTH level in 16.7% of cases. In the control group after 6 months of observation PTH and 25OHD levels did not show significant changes. In both groups significant declining of kidney function were revealed (eGFR decreased in 1^st group from 29.9±18.5 to 24.1±17.0 ml/min, in 2^nd group from 25.8±13.5 to 19.1±13.4 ml/min), however calcium and phosphorus levels remained unchanged. Any other adverse effects related to vitamin D administration were not registered. We can assume that administration of cholecalciferol 2000–3000 IU daily in CKD patients with vitamin D deficiency and SHPT is safe. In the majority of cases this dosage is not efficient to obtain recommended optimal 25OHD level >30ng/ml and to treat or to control progression of SHPT. Further study is required to assess appropriate vitamin D repletion regimen in such patients and its capacity to control SHPT.