Endocrine Abstracts

Introduction: The improvement of vitamin D status is necessary to overcome an impaired calcium-phosphorus metabolism and disturbances in other tissues functioning; safety of medical intervention should include analysis of metabolic changes.

Material and methods: Twenty four apparently healthy volunteers 24.9±2 year were included in the study: Group 1 (11/24) with blood serum levels of 25(OH)D <10 ng/ml and Group 2 (13/24) with 25(OH)D levels 10–20 ng/ml. Assessments were made at baseline; 3 h; 3, 7 and 28 days after intake of 200 000 IU of cholecalciferol oil solution.

Results: At baseline we observed significantly higher mean level of PTH (63.0±17.2 vs 35.3±10.2; P<0.01) with elevation above the upper level of normal range (ULN) in 36.4% in Group 1 whereas in Group 2 levels met normal range in all individuals. Urine calcium/creatinine ratio (CCR), mmol/mmol M±S.D.(Min–Max): Group 1 - 0.25±0.13(0.12–0.58), Group 2 - 0.31±0.21(0.03–0.71); values were less than lower level of normal range (0,1) in 15.4% in Group 2. Blood serum Ca_tot, Ca_ion levels, Ca_ion fraction and P levels were not different between the groups and were within the normal range.

By 28th day 41.6 and 87.5% from all participants achieved 25(OH)D blood serum level >30 ng/ml and >20 ng/ml respectively. By 3d day we observed significant decrease of PTH level in Group 1 (by 27%, P<0.05). There was no significant changes in CCR during follow-up period, but in one individual we observed an increase higher than ULN (maxCCR=0.89) which was transient. We also observed one case of hypercalcemia (maxCa_tot=2.65 mmol/l) which wasn’t associated with increase in Ca_ion.

Conclusion: High-dose oral cholecalciferol treatment for vitamin D deficiency is efficient and safe in young patients regardless of severity of vitamin D deficiency.