Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1995-4-6
pubmed:abstractText
Classification of individuals by their vitamin C intake was investigated in 493 control subjects from a cervical cancer case-control study. The influence of dietary and supplemental sources of vitamin C, as well as demographic and life-style factors, on serum ascorbic acid were examined. Usual dietary intakes of vitamin C were determined from a food frequency questionnaire and recent intakes from a 24-hour recall taken at the time of blood collection. Vitamin supplement information was obtained at both times. In a regression analysis, the factors found to predict serum ascorbic acid were total recent vitamin C intake, an indicator variable for supplement use, body mass index, number of cigarettes smoked per day, race, education, and age. Higher levels of serum ascorbic acid were found among older nonsmoking highly educated leaner white women. Consideration of supplements, in addition to dietary sources of vitamin C, improved correlation coefficients between serum ascorbic acid and usual vitamin C intake from 0.19 to 0.32 and between serum ascorbic acid and recent intake from 0.36 to 0.56. Furthermore, whereas only a twofold difference between the first and fourth quartiles of serum ascorbic acid was observed using recent dietary vitamin C without supplements, this range increased to sixfold with addition of supplement data. Epidemiological studies should consider use of total vitamin C intakes from supplement and food sources to permit accurate classification of individuals.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0163-5581
pubmed:author
pubmed:issnType
Print
pubmed:volume
22
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
207-17
pubmed:dateRevised
2005-11-17
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Importance of supplemental vitamin C in determining serum ascorbic acid in controls from a cervical cancer case-control study: implications for epidemiological studies.
pubmed:affiliation
Division of Cancer Etiology, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892.
pubmed:publicationType
Journal Article