title: Consumption of a calcium and vitamin D-fortified food product does not affect iron status during initial military training: a randomised, double-blind, placebo-controlled trial.
abstract: Ca/vitamin D supplementation maintains bone health and decreases stress fracture risk during initial military training (IMT); however, there is evidence that Ca may negatively affect the absorption of other critical micronutrients, particularly Fe. The objective of this randomised, double-blind, placebo-controlled trial was to determine whether providing 2000 mg/d Ca and 25 µg/d vitamin D in a fortified food product during 9 weeks of military training affects Fe status in young adults. Male (n 98) and female (n 54) volunteers enrolled in US Army basic combat training (BCT) were randomised to receive a snack bar with Ca/vitamin D (n 75) or placebo (snack bar without Ca/vitamin D; n 77) and were instructed to consume 2 snack bars/d between meals throughout the training course. Circulating ionised Ca was higher (P0·05) in markers of Fe status between placebo and Ca/vitamin D groups. Collectively, these data indicate that Ca/vitamin D supplementation through the use of a fortified food product consumed between meals does not affect Fe status during IMT.
authors.affiliation: 1Military Nutrition Division,United States (US) Army Research Institute of Environmental Medicine,Natick,MA 01760,USA.
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Hennigar
authors.affiliation: 2Military Performance Division,United States (US) Army Research Institute of Environmental Medicine,Natick,MA 01760,USA.
authors.forename: Erin
authors.initials: E
authors.lastname: Gaffney-Stomberg
authors.affiliation: 1Military Nutrition Division,United States (US) Army Research Institute of Environmental Medicine,Natick,MA 01760,USA.
authors.forename: Laura J
authors.initials: LJ
authors.lastname: Lutz
authors.affiliation: 3Initial Military Training Center of Excellence,Fort Eustis,VA 23604,USA.
authors.forename: Sonya J
authors.initials: SJ
authors.lastname: Cable
authors.affiliation: 1Military Nutrition Division,United States (US) Army Research Institute of Environmental Medicine,Natick,MA 01760,USA.
authors.forename: Stefan M
authors.initials: SM
authors.lastname: Pasiakos
authors.affiliation: 1Military Nutrition Division,United States (US) Army Research Institute of Environmental Medicine,Natick,MA 01760,USA.
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Young
authors.affiliation: 1Military Nutrition Division,United States (US) Army Research Institute of Environmental Medicine,Natick,MA 01760,USA.
authors.forename: James P
authors.initials: JP
authors.lastname: McClung
mesh_terms: D000293:Adolescent; D000328:Adult; D018798:Anemia, Iron-Deficiency / Q000097:blood / Q000209:etiology*; D015415:Biomarkers / Q000097:blood; D002136:Calcium, Dietary / Q000009:adverse effects* / Q000627:therapeutic use; D004311:Double-Blind Method; D005260:Female; D005527:Food, Fortified / Q000009:adverse effects*; D015775:Fractures, Stress / Q000453:epidemiology / Q000517:prevention & control; D006801:Humans; D019266:Iron, Dietary / Q000037:antagonists & inhibitors* / Q000378:metabolism; D008297:Male; D008889:Military Personnel / Q000193:education; D009752:Nutritional Status; D009825:Oklahoma / Q000453:epidemiology; D064797:Physical Conditioning, Human / Q000009:adverse effects*; D012307:Risk Factors; D062410:Snacks; D013312:Stress, Physiological; D014807:Vitamin D / Q000009:adverse effects* / Q000627:therapeutic use; D055815:Young Adult
chemical_list: D015415:Biomarkers; D002136:Calcium, Dietary; D019266:Iron, Dietary; D014807:Vitamin D
keywords: BCT basic combat training; Bioavailability; Calcium/vitamin D supplementation; DMT1 divalent metal transporter 1; IMT initial military training; Iron deficiency; Minerals