Does vitamin D(3) dosing schedule influence treatment efficacy in nursing home residents with vitamin D deficiency?

Author(s): Holick MF

Affiliation(s): MF Holick is a Professor of Medicine, Physiology and Biophysics in the Division of Endocrinology, Diabetes and Nutrition at Boston University School of Medicine, Boston, MA, USA.

Publication date & source: 2008-10-28, Nat Clin Pract Endocrinol Metab., [Epub ahead of print]

Publication type:

Vitamin D deficiency is a common problem among elderly nursing home residents. In this Practice Point commentary, I discuss the findings and limitations of a randomized, controlled trial by Chel et al. that evaluated the effect of equivalent oral doses of vitamin D(3) given as 600 IU daily, 4,200 IU weekly or 18,000 IU monthly. Regardless of the dosing schedule, oral administration of vitamin D(3) was associated with increased levels of serum 25-hydroxyvitamin D and reduced levels of parathyroid hormone in the study cohort. Daily administration of vitamin D(3) was found to be more effective than either weekly or monthly administration. The addition of calcium supplementation for a 2-week period did not appreciably augment the effects of vitamin D(3) supplementation. Here, I highlight the issues to consider when interpreting studies of vitamin D(3) supplementation, its effect on vitamin D status, and the consequences for calcium and bone metabolism.