Vitamin D deficiency is common and various supplementations regimens are in use. The purpose of this audit was to compare the efficacy of two short-term colecalciferol loading regimens in treating Vitamin D deficiency. Sixty-four consecutive patients with serum 25OH VitaminD ≤30 nmol/L were assigned to 12 or 16 weeks treatment with 40,000 IU colecalciferol orally once a week. The main endpoint was to identify which duration of treatment is adequate for achievement of sufficiency (serum 25OH VitaminD ≥75 nmol/L). We also looked at the relationship between the change in 25OHVitaminD levels with body mass index(BMI), pre-treatment 25OHVitaminD and corrected calcium. In the group treated for 12 weeks (n=22) there was a mean increment of 25OHVitaminD of 74.82±20.79 nmol/L with a final 25OHVitaminD of 95.77±20.35 nmol/L. In the group treated for 16 weeks (n=35) the 25OH VitaminD increment was 76.29±29.87 nmol/L with a final level of 96.00±28.22 nmol/L. There was no statistical difference in the increment or post-treatment 25OHVitaminD achieved between the two groups (P 0.83 and P 0.97 respectively). Additionally, there was no difference in the proportion of patients who reached sufficiency (n=18, 81.8% in the 12 week treatment vs n=28, 80% in the 16 week treatment group, P 0.71). Overall there was a negative correlation between the increment in 25OHVitaminD and BMI (r −0.277, P 0.04) and the increment in 25OHVitaminD and the pre-treatment 25OH VitaminD (r −0.315, P 0.017). Serum corrected calcium post-treatment significantly increased compared with the pre-treatment levels (2.24±0.01 versus 2.19±0.06, P 0.003). We conclude that a 12 week course of 40,000IU colecalciferol weekly corrects Vitamin D deficiency in the majority of patients, with no additional benefit in extending the loading course to 16 weeks. It seems that Vitamin D deficient overweight and obese patients would require higher doses to achieve sufficiency.
Declaration of interest: There is no conflict of interest that could be perceived as prejudicing the impartiality of the research reported.
Funding: No specific grant from any funding agency in the public, commercial or not-for-profit sector.