Endocrine Abstracts

Aim: To minimize the duration of vitamin-D insufficiency, current treatment regimes are initiated with an oral bolus dose of cholecalciferol. We have previously developed an algorithm (# Dekristol caps/Vigantol ml =(80 nmol/l – initial [s-25-OH-d-vit])/7 nmol/l) for determining the dosage of this bolus, aimed at reaching a serum 25-OH vitamin-D of 80 nmol/l. Our main aim was to investigate the accuracy of this algorithm.

Materials: A retrospective study of 88 patients attending the out-patient clinic with low vitamin-D status. 60 patients had been treated with a bolus dose of cholecalciferol, estimated by the algorithm, as either capsules (Dekristol, 20.000 IU/capsule) or drops (Vigantol, 20.000 IU/ml), along with supplementation treatment consisting of Unikalk Forte 2 to 4 tbl./day (1520–3040 IU). 28 patients received supplementation treatment alone (no-bolus group).

Results: The average baselines were <25–nmol/l (below the assay’s detectable range) in the bolus group and 32,0 nmol/l in the no-bolus group. Follow-up samples were taken after 116 (±70) days. Both groups had received daily supplementation of cholecalciferol, averaging at 1787 IU and 1924 IU respectively. At the follow-up, the bolus group had an increase in s-25-OH-vitamin-D of 34.9 nmol/l – significantly higher (P=0,005) than in the other group (19.0 nmol/l). The bolus treated patients had a s-25-OH-vitamin-D of 55.9 nmol/l, 95% CI 46.3–58.9 – significantly lower than the desired value of 80 nmol/l (P<0.001).

Conclusion: Our findings suggest that our treatment regime wasn’t sufficient to increase the serum 25-OH vitamin-D to 80 nmol/l. Based on present data we have developed a new algorithm incorporating patient BMI, which we plan to validate in a prospective study.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.