Randomized clinical trial to comparing efficacy of daily, weekly and monthly administration of vitamin D.

The comparative efficacy and safety profiles of selected daily 1000 IU, weekly 7000 IU and monthly 30,000 IU vitamin D -not previously investigated-will be evaluated. Here, a prospective, randomized clinical trial, comparing efficacy and safety of a daily single dose of 1000 IU (group A) to a once-weekly 7000 IU dose (group B), or monthly 30,000 IU dose (group C) of vitamin D. The present study is a controlled, randomized, open-label, multicenter clinical trial, 3  months in duration. Sixty-four adult subjects with vitamin D deficiency (25OHD<20 ng/ml), were included according to the inclusion and exclusion criteria. Dose-responses for increases in serum vitamin 25OHD were statistically equivalent for each of the three groups: A, B and C. Outcomes were 13.0 ± 1.5; 12.6 ± 1.1 and 12.9 ± 0.9 ng/ml increases in serum 25OHD per 1000 IU, daily, weekly and monthly, respectively. The treatment of subjects with selected doses restored 25OHD values to levels above 20 ng/ml in all groups. Treatment with distinct administration frequency of vitamin D did not exhibit any differences in safety parameters. The daily, weekly and monthly administrations of daily equivalent of 1000 IU of vitamin D provide equal efficacy and safety profiles.