Effectiveness and safety of a high-dose weekly vitamin D (20,000 IU) protocol in older adults living in residential care

Fabio Feldman, Crystal Moore, Liz Da Silva, Gina Gaspard, Larry Gustafson, Sonia Singh, Susan I. Barr, David D. Kitts, Wangyang Li, Hope A. Weiler, Timothy J. Green

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7 Citations (Scopus)


Objectives To report 25 hydroxyvitamin D (25OHD) concentrations, an indicator of vitamin D status, in older adults living in residential care 1 year after a protocol of weekly 20,000 IU of vitamin D was started. Design Cross-sectional. Setting Five residential care facilities in British Columbia, Canada. Participants Residents aged 65 and older from five facilities (N = 236). Measurements Participants provided a blood sample. Demographic and health information was obtained from the medical record. Results Mean 25OHD was 102 nmol/L (95% confidence interval (CI) = 98-106 nmol/L). Three percent of residents had a 25OHD concentration of less than 40 nmol/L, 6% <50 nmol/L, and 19% <75 nmol/L. In those who received 20,000 IU/wk or more for 6 months or longer (n = 147), mean 25OHD was 112 nmol/L (95% CI = 108-117 nmol/L), and none had a 25OHD level of less than 50 nmol/L. Hypercalcemia (>2.6 mmol/L), a potential consequence of too much vitamin D, was present in 14%, although 25OHD levels did not differ in those with and without hypercalcemia (108 vs 101 nmol/L; P =.17). Conclusion Twelve months after implementation of a 20,000-IU/wk vitamin D protocol for older adults in residential care, mean 25OHD concentrations were high, and there was no evidence of poor vitamin D status. Given the absence of demonstrated benefit of high 25OHD concentrations to the residential care population, dosages less than 20,000 IU/wk of vitamin D are recommended.

Original languageEnglish
Pages (from-to)1546-1550
Number of pages5
JournalJournal of the American Geriatrics Society
Issue number8
Publication statusPublished or Issued - Aug 2014


  • elderly
  • residential care
  • safety
  • vitamin D

ASJC Scopus subject areas

  • Geriatrics and Gerontology

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