Endocrine Abstracts

Introduction

It has been estimated that prevalence of vitamin D deficit (25(OH)D) in the world is between 20 and 100%, depending on age group, ethnicity and region. In European population, the prevalence is around 40%. The Endocrine society guidelines recommend the supplementation of vitamin D when vitamin D deficiency is confirmed. The objective of this work is to evaluate the effect of 25(OH)D supplementation on phospho-calcium metabolites: calcium (Ca), phosphorus (Ph) and parathormone (PTH).

Methods

Retrospective study of 185 individuals diagnosed with 25(OH)D deficit in routine analyses and to whom supplementation was prescribed. Individuals with hyperparathyroidism (HPTP) were excluded. We analysed the age, sex, glomerular filtration rate (GFR), Ca, Ph, 25(OH)D and PTH baseline, at 6 and 12 months(M) after supplementation. Two levels of deficiency of 25(OH)D were defined: deficiency if 25(OH)D<20 ng/ml and insufficiency if 20 ng/ml≤ 25(OH)D <30 ng/ml. The various formulations of 25(OH)D were prescribed, according to the recommended dosage. Statistical analysis was performed in Excel® with significance level P=0.05.

Results

185 patients, 51.9% female with a mean age of 69 years and mean GFR 91.6 ml/min. In the pre-supplementation phase 74.6% had 25(OH)D deficiency and 25.2% had insufficiency. 26.5% of patients were supplemented with calcifediol and 73.5% with cholecalciferol. The mean values of analysed metabolites at 0, 6 and 12 months were respectively: 25(OH)D 16 ng/ml, 30 ng/dl and 29.95 ng/dl (P<0.001); Ca 9.47 mg/dl, 9.55 mg/dl and 9.57 mg/dl (P=0.208); Ph 3.34 mg/dl, 3.5 mg/dl and 3.22 mg/dl (P=0.178); PTH 88.1 pg/ml, 74.4 pg/ml and 82.4 pg/ml (P=0.077). We did a sub-analysis of patients with renal failure (GFR<60 and 60<GFR<90 ml/min) with similar results, without statistical significance (GFR<60 ml/min: Ca P=0.49; Ph P=0.55; PTH P=0.19 and 60<GFR<90 ml/min: Ca P=0.32; Ph P=0.28; PTH P=0.29).

Conclusion

In this study it was found that vitamin D supplementation is an effective therapy in the treatment of this deficiency. After 12 months of 25(OH)D supplementation, there was no significant statistical variation in the phospho-calcic metabolites. Renal failure did not influence the results obtained in this study. These results are in line with those previously published in the literature.