Document Detail

Haptoglobin genotype modifies the association between dietary vitamin C and serum ascorbic acid deficiency.
MedLine Citation:
PMID:  20926521     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: Haptoglobin (which is encoded by the Hp gene) is a hemoglobin-binding protein that has antioxidant properties and a common polymorphism that consists of 2 structurally different alleles: Hp1 and Hp2. The capacity of Hp2 to inhibit oxidation and vitamin C depletion is less than that of Hp1, but the influence on vitamin C requirements remains unknown.
OBJECTIVE: This study aimed to determine whether the Hp polymorphism modifies the association between dietary vitamin C and serum ascorbic acid deficiency (<11 μmol/L).
DESIGN: Nonsmoking men and women (n = 1046) between 20 and 29 y of age participated in the Toronto Nutrigenomics and Health Study. Blood samples were collected after the subjects had fasted overnight to determine serum ascorbic acid concentrations by HPLC and for genotyping. A 196-item food-frequency questionnaire was used to estimate vitamin C intake.
RESULTS: A gene-diet interaction on serum ascorbic acid was observed (P = 0.02). The overall odds ratio (95% CI) for serum ascorbic acid deficiency was 2.84 (1.73, 4.65) for subjects who did not meet the Recommended Dietary Allowance for vitamin C compared with those who did. The corresponding odds ratios were 4.77 (2.36, 9.65) for the Hp2-2 genotype and 1.69 (0.80, 3.63) for carriers of the Hp1 allele.
CONCLUSIONS: Individuals with the Hp2-2 genotype had an increased risk of deficiency if they did not meet the Recommended Dietary Allowance for vitamin C, whereas carriers of the Hp1 allele did not. The findings suggest that the greater antioxidant capacity of Hp1 might spare serum ascorbic acid.
Leah E Cahill; Ahmed El-Sohemy
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't     Date:  2010-10-06
Journal Detail:
Title:  The American journal of clinical nutrition     Volume:  92     ISSN:  1938-3207     ISO Abbreviation:  Am. J. Clin. Nutr.     Publication Date:  2010 Dec 
Date Detail:
Created Date:  2010-11-24     Completed Date:  2010-12-23     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0376027     Medline TA:  Am J Clin Nutr     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1494-500     Citation Subset:  AIM; IM    
Department of Nutritional Sciences, University of Toronto, Toronto, Canada.
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MeSH Terms
Ascorbic Acid / administration & dosage*,  blood
Ascorbic Acid Deficiency / blood*
Haptoglobins / genetics*
Odds Ratio
Polymorphism, Genetic*
Young Adult
Reg. No./Substance:
0/Haptoglobins; 50-81-7/Ascorbic Acid

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

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