title: Low iron status as a factor of increased bone resorption and effects of an iron and vitamin D-fortified skimmed milk on bone remodelling in young Spanish women.
abstract: OBJECTIVE
  This study aimed to determine whether there is a relationship between iron status and bone metabolism, and to compare the effects of the consumption, as part of the usual diet, of an iron or iron and vitamin D-fortified skimmed milk on bone remodelling in iron-deficient women.
  
  
  METHODS
  Young healthy iron-deficient or iron-sufficient women (serum ferritin ≤30 ng/mL or >30 ng/mL, respectively) were recruited. Iron-deficient women were assigned to a nutritional intervention consisting of a randomised, controlled, double-blind, parallel design trial of 16 weeks during winter. They consumed, as part of their usual diet, an iron (Fe group, n = 54) or iron and vitamin D-fortified (Fe+D group, n = 55) flavoured skimmed milk (iron, 15 mg/day; vitamin D3, 5 μg/day, 200 IU). The iron-sufficient women followed their usual diet without supplementation (R group, n = 56). Dietary intake, body weight, iron biomarkers, 25-hydroxyvitamin D (25OHD), parathyroid hormone (PTH), procollagen-type 1 N-terminal propeptide (P1NP), and aminoterminal telopeptide of collagen I (NTx) were determined.
  
  
  RESULTS
  Negative correlations were found between baseline log-ferritin and log-NTx (p < 0.001), and between transferrin and P1NP (p = 0.002). Serum 25OHD increased (from 62 ± 21 to 71 ± 21 nmol/L, mean ± SD, p < 0.001) while P1NP and NTx decreased in Fe+D during the assay (p = 0.004 and p < 0.001, respectively). NTx was lower in Fe+D compared to Fe at week 8 (p < 0.05) and was higher in Fe and Fe+D compared to R throughout the assay (p < 0.01). PTH did not show changes.
  
  
  CONCLUSIONS
  Iron deficiency is related with higher bone resorption in young women. Consumption of a dairy product that supplies 5 μg/day of vitamin D3 reduces bone turnover and increases circulating 25OHD to nearly reach an optimal vitamin D status, defined as 25OHD over 75 nmol/L.
authors.affiliation: Institute of Food Science, Technology and Nutrition (ICTAN), Spanish National Research Council (CISC), C/José Antonio Novais 10, 28040, Madrid, Spain.
authors.forename: Laura
authors.initials: L
authors.lastname: Toxqui
authors.forename: Ana M
authors.initials: AM
authors.lastname: Pérez-Granados
authors.forename: Ruth
authors.initials: R
authors.lastname: Blanco-Rojo
authors.forename: Ione
authors.initials: I
authors.lastname: Wright
authors.forename: Concepción
authors.initials: C
authors.lastname: de la Piedra
authors.forename: M Pilar
authors.initials: MP
authors.lastname: Vaquero
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D016723:Bone Remodeling / Q000502:physiology*; D001862:Bone Resorption / Q000453:epidemiology / Q000209:etiology / Q000628:therapy*; D024042:Collagen Type I / Q000097:blood; D004032:Diet; D004311:Double-Blind Method; D005260:Female; D005293:Ferritins / Q000097:blood; D005527:Food, Fortified; D006801:Humans; D007501:Iron / Q000008:administration & dosage*; D000090463:Iron Deficiencies; D008892:Milk / Q000737:chemistry; D009752:Nutritional Status / Q000502:physiology; D010281:Parathyroid Hormone / Q000097:blood; D010446:Peptide Fragments / Q000097:blood; D010455:Peptides / Q000097:blood; D011347:Procollagen / Q000097:blood; D013030:Spain / Q000453:epidemiology; D014168:Transferrin / Q000032:analysis; D014807:Vitamin D / Q000008:administration & dosage* / Q000031:analogs & derivatives / Q000097:blood; D055815:Young Adult
chemical_list: D024042:Collagen Type I; D010281:Parathyroid Hormone; D010446:Peptide Fragments; D010455:Peptides; D011347:Procollagen; D014168:Transferrin; C052929:collagen type I trimeric cross-linked peptide; C047202:procollagen Type I N-terminal peptide; D014807:Vitamin D; D005293:Ferritins; C104450:25-hydroxyvitamin D; D007501:Iron