Vitamin D Supplement Doses and Serum 25-Hydroxyvitamin D in the Range Associated with Cancer Prevention
- 1University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093, U.S.A.
- 2GrassrootsHealth, P.O. Box 234208, Encinitas, CA 92023, U.S.A.
- 3Creighton University, 2500 California Plaza, Omaha, NE 68178, U.S.A.
- Correspondence to: Robert P. Heaney, MD, Creighton University Medical Center, 601 North 30th Street – Suite 4841, Omaha, NE 68131, U.S.A. Tel: +1 4022804029, Fax: +1 4022804751, e-mail: rheaney{at}creighton.edu
Abstract
Background: Studies indicate that intake of vitamin D in the range from 1,100 to 4,000 IU/d and a serum 25-hydroxyvitamin D concentration [25(OH)D] from 60-80 ng/ml may be needed to reduce cancer risk. Few community-based studies allow estimation of the dose–response relationship between oral intake of vitamin D and corresponding serum 25(OH)D in the range above 1,000 IU/d. Materials and Methods: A descriptive study of serum 25(OH)D concentration and self-reported vitamin D intake in a community-based cohort (n=3,667, mean age 51.3±13.4 y). Results: Serum 25(OH)D rose as a function of self-reported vitamin D supplement ingestion in a curvilinear fashion, with no intakes of 10,000 IU/d or lower producing 25(OH)D values above the lower-bound of the zone of potential toxicity (200 ng/ml). Unsupplemented all-source input was estimated at 3,300 IU/d. The supplemental dose ensuring that 97.5% of this population achieved a serum 25(OH)D of at least 40 ng/ml was 9,600 IU/d. Conclusion: Universal intake of up to 40,000 IU vitamin D per day is unlikely to result in vitamin D toxicity.
- Received December 22, 2010.
- Revision received January 18, 2011.
- Accepted January 19, 2011.
- Copyright© 2011 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved
