title: Associations between dietary iron and zinc intakes, and between biochemical iron and zinc status in women.
abstract: Iron and zinc are found in similar foods and absorption of both may be affected by food compounds, thus biochemical iron and zinc status may be related. This cross-sectional study aimed to: (1) describe dietary intakes and biochemical status of iron and zinc; (2) investigate associations between dietary iron and zinc intakes; and (3) investigate associations between biochemical iron and zinc status in a sample of premenopausal women aged 18-50 years who were recruited in Melbourne and Sydney, Australia. Usual dietary intakes were assessed using a 154-item food frequency questionnaire (n = 379). Iron status was assessed using serum ferritin and hemoglobin, zinc status using serum zinc (standardized to 08:00 collection), and presence of infection/inflammation using C-reactive protein (n = 326). Associations were explored using multiple regression and logistic regression. Mean (SD) iron and zinc intakes were 10.5 (3.5) mg/day and 9.3 (3.8) mg/day, respectively. Median (interquartile range) serum ferritin was 22 (12-38) μg/L and mean serum zinc concentrations (SD) were 12.6 (1.7) μmol/L in fasting samples and 11.8 (2.0) μmol/L in nonfasting samples. For each 1 mg/day increase in dietary iron intake, zinc intake increased by 0.4 mg/day. Each 1 μmol/L increase in serum zinc corresponded to a 6% increase in serum ferritin, however women with low serum zinc concentration (AM fasting < 10.7 μmol/L; AM nonfasting < 10.1 μmol/L) were not at increased risk of depleted iron stores (serum ferritin <15 μg/L; p = 0.340). Positive associations were observed between dietary iron and zinc intakes, and between iron and zinc status, however interpreting serum ferritin concentrations was not a useful proxy for estimating the likelihood of low serum zinc concentrations and women with depleted iron stores were not at increased risk of impaired zinc status in this cohort.
authors.affiliation: Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition, Deakin University, 221 Burwood Highway, Burwood, Victoria 3125, Australia. k.lim@deakin.edu.au.
authors.forename: Karen
authors.initials: K
authors.lastname: Lim
authors.affiliation: Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition, Deakin University, 221 Burwood Highway, Burwood, Victoria 3125, Australia. alison.booth@deakin.edu.au.
authors.forename: Alison
authors.initials: A
authors.lastname: Booth
authors.affiliation: Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition, Deakin University, 221 Burwood Highway, Burwood, Victoria 3125, Australia.
authors.forename: Ewa A
authors.initials: EA
authors.lastname: Szymlek-Gay
authors.affiliation: Department of Human Nutrition, University of Otago, PO Box 56, Dunedin 9054, New Zealand. rosalind.gibson@otago.ac.nz.
authors.forename: Rosalind S
authors.initials: RS
authors.lastname: Gibson
authors.affiliation: Department of Human Nutrition, University of Otago, PO Box 56, Dunedin 9054, New Zealand. karl.bailey@otago.ac.nz.
authors.forename: Karl B
authors.initials: KB
authors.lastname: Bailey
authors.affiliation: Australian Red Cross Blood Service, 17 O'Riordan Street, Alexandria, New South Wales 2015, Australia. dirving@redcrossblood.org.au.|University of Technology, Sydney 15 Broadway, Ultimo, New South Wales 2007, Australia. dirving@redcrossblood.org.au.
authors.forename: David
authors.initials: D
authors.lastname: Irving
authors.affiliation: Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition, Deakin University, 221 Burwood Highway, Burwood, Victoria 3125, Australia. caryl.nowson@deakin.edu.au.
authors.forename: Caryl
authors.initials: C
authors.lastname: Nowson
authors.affiliation: Centre for Physical Activity and Nutrition Research, School of Exercise and Nutrition, Deakin University, 221 Burwood Highway, Burwood, Victoria 3125, Australia. lynn.riddell@deakin.edu.au.
authors.forename: Lynn
authors.initials: L
authors.lastname: Riddell
mesh_terms: D000293:Adolescent; D000328:Adult; D001315:Australia; D002097:C-Reactive Protein / Q000378:metabolism; D003430:Cross-Sectional Studies; D019587:Dietary Supplements; D002149:Energy Intake; D005260:Female; D005293:Ferritins / Q000097:blood; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D019266:Iron, Dietary / Q000008:administration & dosage* / Q000097:blood*; D008875:Middle Aged; D015596:Nutrition Assessment; D009752:Nutritional Status; D017697:Premenopause; D055815:Young Adult; D015032:Zinc / Q000008:administration & dosage* / Q000097:blood*
chemical_list: D006454:Hemoglobins; D019266:Iron, Dietary; D002097:C-Reactive Protein; D005293:Ferritins; D015032:Zinc