Document Detail


Vitamin D supplementation during Antarctic winter.
MedLine Citation:
PMID:  19225122     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Persons with limited exposure to ultraviolet B light, including space travelers, may not receive enough vitamin D. Recent studies indicate that optimal serum 25-hydroxyvitamin D [25(OH)D] should be > or = 80 nmol/L. OBJECTIVE: This study was designed to evaluate the effectiveness of 3 doses of vitamin D to raise and maintain 25(OH)D to a concentration >80 nmol/L in persons with limited ultraviolet B light exposure. DESIGN: This was a 5-mo, prospective, randomized, double-blind study of vitamin D supplementation. It was conducted during winter in Antarctica at the McMurdo Station, when ultraviolet B radiation levels are essentially zero. The 55 subjects were randomly divided into 3 groups for vitamin D supplementation: 2000 IU/d (n = 18), 1000 IU/d (n = 19), and 400 IU/d (n = 18). An additional 7 subjects did not take supplements or took supplements of their own choosing. Blood samples were collected about every 2 mo during the winter. RESULTS: About 5 mo after supplementation started, 25(OH)D increased to 71 +/- 23 nmol/L in the 2000-IU/d group, 63 +/- 25 nmol/L in the 1000-IU/d group, and 57 +/- 15 nmol/L in the 400-IU/d group and decreased to 34 +/- 12 nmol/L in the group not taking supplements. CONCLUSIONS: These data will enable us to provide space crews with evidence-based recommendations for vitamin D supplementation. The findings also have implications for other persons with limited ultraviolet light exposure, including polar workers and the elderly.
Authors:
Scott M Smith; Keri K Gardner; James Locke; Sara R Zwart
Publication Detail:
Type:  Journal Article; Randomized Controlled Trial; Research Support, U.S. Gov't, Non-P.H.S.     Date:  2009-02-18
Journal Detail:
Title:  The American journal of clinical nutrition     Volume:  89     ISSN:  1938-3207     ISO Abbreviation:  Am. J. Clin. Nutr.     Publication Date:  2009 Apr 
Date Detail:
Created Date:  2009-03-19     Completed Date:  2009-04-06     Revised Date:  2009-05-15    
Medline Journal Info:
Nlm Unique ID:  0376027     Medline TA:  Am J Clin Nutr     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1092-8     Citation Subset:  AIM; IM    
Affiliation:
Space Life Sciences Directorate, NASA Johnson Space Center, Houston, TX 77058, USA. scott.m.smith@nasa.gov
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MeSH Terms
Descriptor/Qualifier:
Adult
Antarctic Regions
Bone Density Conservation Agents / administration & dosage*,  biosynthesis
Diet*
Dietary Supplements
Dose-Response Relationship, Drug
Double-Blind Method
Female
Humans
Male
Prospective Studies
Seasons
Sunlight*
Vitamin D / administration & dosage*,  analogs & derivatives*,  biosynthesis,  blood
Vitamin D Deficiency / blood,  prevention & control
Chemical
Reg. No./Substance:
0/Bone Density Conservation Agents; 1406-16-2/Vitamin D; 64719-49-9/25-hydroxyvitamin D

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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