50,000 IU of vitamin D every two weeks – Jordan conclusion - RCT July 2017

Vitamin D Dosing Strategies Among Jordanians With Hypovitaminosis D.

J Pharm Pract. 2017 Apr;30(2):172-179. doi: 10.1177/0897190015626334. Epub 2016 Jul 8.

Khawaja N1, Liswi M1, El-Khateeb M1,2, Hyassat D1, Bajawi D1, Elmohtaseb M1, Alkhateeb H1, Ajlouni K1.
1 The National Center (Institute) for Diabetes, Endocrinology and Genetics (NCDEG), The University of Jordan, Amman, Jordan.
2 Department of Pathology, Microbiology and Forensic Medicine, The University of Jordan, Amman, Jordan.

OBJECTIVE:
To compare between weekly and daily cholecalciferol in patients with hypovitaminosis D and to determine the optimal maintenance dose.

METHODS:
Seventy-one volunteers with hypovitaminosis D were randomly assigned to 2 dose regimens: cholecalciferol 50 000 IU weekly for 8 weeks, then 50 000 IU monthly for 2 months (group A) and 7000 IU daily for 8 weeks, then 12 500 IU weekly for 2 months (group B ). Cholecalciferol was stopped for 2 months and reintroduced as 50 000 IU bimonthly for group A and 50 000 IU monthly for group B.

RESULTS:
Two months after therapy, the mean serum 25-hydroxyvitamin D (25(OH)D) level increased from 11.4 to 51.2 ng/mL and from 11.7 to 44.9 ng/mL in groups A and B, respectively ( P = .065). The levels of 25(OH)D declined similarly in both groups during maintenance and after holding therapy. After resuming cholecalciferol, 25(OH)D levels increased to 33.8 and 28.8 ng/mL in groups A and B, respectively ( P = .027). There was a negative correlation between serum 25(OH)D levels and body mass index (BMI; P = .040).

CONCLUSION:
Timing and frequency of the dosing (daily vs weekly) have no effect on the rise in serum 25(OH)D levels as long as the accumulative dose of cholecalciferol is similar. Cholecalciferol 50 000 IU bimonthly is required to maintain sufficient 25(OH)D levels.

PMID: 26787629 DOI: 10.1177/0897190015626334

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