Correcting poor vitamin D status: Do older adults need higher repletion doses of vitamin D3 than younger adults?
Susan J. Whiting 1 *, Mona S. Calvo 2
Molecular Nutrition & Food Research 3 May 2010
1College of Pharmacy and Nutrition, University of Saskatchewan, Saskatoon, Saskatchewan, Canada
2Office of Applied Research and Safety Assessment Center for Food Safety and Applied Nutrition, US Food and Drug Administration Laurel, MD, USA
email: Susan J. Whiting (susan.whiting@usask.ca
Correspondence to Susan J. Whiting, College of Pharmacy and Nutrition, University of Saskatchewan, 110 Science Place, Saskatoon, Saskatchewan, S7N 5C9 Canada Fax:+1-306-966-6377
We conducted an examination of recent studies to determine whether older adults (65 years) need higher levels of supplementary vitamin D than young adults when attempting to replete vitamin D status in deficient subjects, i.e. those with levels of 25-hydroxyvitamin D less than 75 nmol/L. As data on repletion with vitamin D2 have recently been published, we restricted our discussion to the use of vitamin D3 from dietary supplements, prescriptions for large oral doses, and bolus dosing or injections. Most published dosing regimens failed to achieve 75 nmol/L in most all subjects, whether young adults (<65 years) or older adults (65 years). Whether as daily or bolus oral supplementation, elderly subjects appeared to need more vitamin D3 compared with younger adults, however, baseline levels, endpoints, study duration, compliance, and other factors were different among studies.
To ensure most subjects are replete in vitamin D, a daily dose of more than 50 ug (2000 IU) in younger and 125 ug (5000 IU) is required. Other strategies including bolus and loading doses are described. No study reported adverse effects of using oral intakes about the current upper level of 50 g (2000 IU).
Received: 8 November 2009; Revised: 17 February 2010; Accepted: 22 February 2010
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