HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Talwar, S. A Articles by Yeh, J. K PubMed PubMed Citation Articles by Talwar, S. A Articles by Yeh, J. K Agricola Articles by Talwar, S. A Articles by Yeh, J. K

Dose response to vitamin D supplementation among postmenopausal African American women^1,2,3

¹ From the Bone Mineral Research Center, Winthrop University Hospital, Mineola, NY

Background: Reports on the dose response to vitamin D are conflicting, and most data were derived from white men and women.

Objective: The objective was to determine the response of serum 25-hydroxyvitamin D [25(OH)D] to oral vitamin D₃ supplementation in an African American population.

Design: Healthy black postmenopausal women (n = 208) participated in a vitamin D₃ supplementation trial for a period of 3 y. Analyses were done in the vitamin D supplementation arm (n = 104) to quantify the response in serum 25-hydroxyvitamin D concentrations at a steady state vitamin D input. The participants received 20 µg/d (800 IU) oral vitamin D₃ for the initial 2 y and 50 µg/d (2000 IU) for the third year.

Results: Supplementation with 20 µg/d (800 IU/d) vitamin D₃ raised the mean serum 25(OH)D concentration from a baseline of 46.9 ± 20.6 nmol/L to 71.4 ± 21.5 nmol/L at 3 mo. The mean (±SD) concentration of serum 25(OH)D was 87.3 ± 27.0 nmol/L 3 mo after supplementation increased to 50 µg/d (2000 IU/d). All participants achieved a serum 25(OH)D concentration >35 nmol/L, 95% achieved a concentration >50 nmol/L, but only 60% achieved a concentration >75 nmol/L. All patients had concentrations <153 nmol/L. On the basis of our findings, an algorithm for prescribing vitamin D so that patients reach optimal serum concentrations was developed. The algorithm suggests a dose of 70 µg (2800 IU/d) for those with a concentration >45 nmol/L and a dose of 100 µg (4000 IU/d) for those with a concentration <45 nmol/L.

Conclusions: Supplementation with 50 µg/d (2000 IU/d) oral vitamin D₃ is sufficient to raise serum 25-hydroxyvitamin D concentrations to >50 nmol/L in almost all postmenopausal African American women. However, higher doses were needed to achieve concentrations >75 nmol/L in many women in this population.

Key Words: Ethnicity • vitamin D • 25-hydroxyvitamin D • osteoporosis • vitamin D deficiency • African Americans