Supplementation with 80,000 IU vitamin D3/month between November and April corrects vitamin D insufficiency without overdosing: Effect on serum 25-hydroxyvitamin D serum concentrations

Abstract

Introduction: Vitamin D insufficiency, defined by a 25-hydroxyvitamin D (25OHD) serum concentration<20ng/mL, is highly frequent in the French general population, especially between November and April. The aim of this study was to evaluate whether 80,000 IU vitamin D3 every month during this period of the year was able to maintain a 25OHD level between 20 and 60ng/mL in apparently healthy subjects whatever their basal vitamin D status.

Methods: Ninety-eight subjects volunteered to receive an 80,000 IU vitamin D3 dose every month between November 2014 and April 2015. Serum 25OHD, calcemia and calciuria were measured just before the first dose (Month 0), just before the 4th dose (M4), and one month after the 6th dose (M7).

Results: At M0, 25OHD was 17.5±9.5ng/mL. Sixty subjects (61.2%) had a 25OHD<20ng/mL and 25 (25.5%) had a 25OHD<10ng/mL. 25OHD increased significantly at M4 (35.3±8.0ng/mL) and M7 (40.1±8.5) without change in calcemia and calciuria. At M4, 2 subjects had a 25OHD slightly below 20ng/mL (17.6 and 19.7ng/mL), and none had a concentration>60ng/mL. At M7, all had a serum 25OHD>20ng/mL and 2 subjects had a value slightly above 60ng/mL (62.1 and 63.2ng/mL).

Conclusion: A monthly supplementation with 80,000 IU vitamin D3 between November and April corrected vitamin D insufficiency in subjects in whom it was initially very frequent, without overdosing. This protocol is simple, safe and costless, and can be easily implemented when physicians detect risk factors for hypovitaminosis D in patients for whom a 25OHD measurement is not indicated.