title: Habitual high phosphorus intakes and foods with phosphate additives negatively affect serum parathyroid hormone concentration: a cross-sectional study on healthy premenopausal women.
abstract: OBJECTIVE
  Foods can contain natural phosphorus (NP) and phosphate-containing food additives (AP). The main objective of the present study was to investigate whether NP and AP of habitual diets differ in their effects on markers of Ca metabolism. We also investigated the impact of total habitual dietary P intake on markers of Ca metabolism.
  
  
  METHODS
  Cross-sectional study. Fasting blood samples were collected and participants kept a 4 d food record, from which dietary intake of total P and the consumption of NP (milk and cheese, excluding processed cheese) and AP (processed cheese) sources were calculated. Participants were divided into groups according to their NP- and AP-containing food consumption and into quartiles according to their total P intake.
  
  
  METHODS
  Southern Finland.
  
  
  METHODS
  One hundred and forty-seven healthy premenopausal women aged 31-43 years.
  
  
  RESULTS
  Relative to the lowest total dietary P quartile, mean serum parathyroid hormone (S-PTH) concentration was higher (P = 0.048, analysis of covariance (ANCOVA)) and the mean serum ionized Ca concentration lower (P = 0.016, ANCOVA) in the highest P intake quartile. Mean S-PTH concentrations were higher among participants who consumed processed cheese (P = 0.027, ANCOVA) and less milk and other cheese than processed cheese (P = 0.030, ANCOVA).
  
  
  CONCLUSIONS
  High total habitual dietary P intake affected S-PTH unfavourably. Furthermore, phosphate additives may have more harmful effects on bone than other P sources, as indicated by higher mean S-PTH concentration among participants who consumed AP-containing foods. Because of the high dietary P intake and current upward trend in consumption of processed foods in Western countries, these findings may have important public health implications.
authors.affiliation: Calcium Research Unit, Department of Applied Chemistry and Microbiology, PO Box 66, FIN-00014, University of Helsinki, Finland.
authors.forename: Virpi E
authors.initials: VE
authors.lastname: Kemi
authors.forename: Hannu J
authors.initials: HJ
authors.lastname: Rita
authors.forename: Merja U M
authors.initials: MU
authors.lastname: Kärkkäinen
authors.forename: Heli T
authors.initials: HT
authors.lastname: Viljakainen
authors.forename: Marika M
authors.initials: MM
authors.lastname: Laaksonen
authors.forename: Terhi A
authors.initials: TA
authors.lastname: Outila
authors.forename: Christel J E
authors.initials: CJ
authors.lastname: Lamberg-Allardt
mesh_terms: D000328:Adult; D000818:Animals; D002118:Calcium / Q000097:blood*; D002611:Cheese; D003430:Cross-Sectional Studies; D004032:Diet; D005260:Female; D005387:Finland; D005503:Food Additives / Q000009:adverse effects*; D006801:Humans; D008892:Milk; D015999:Multivariate Analysis; D010281:Parathyroid Hormone / Q000097:blood*; D010710:Phosphates / Q000008:administration & dosage / Q000009:adverse effects*; D010758:Phosphorus / Q000008:administration & dosage / Q000009:adverse effects*; D016226:Phosphorus, Dietary / Q000008:administration & dosage / Q000009:adverse effects*; D017697:Premenopause
chemical_list: D005503:Food Additives; D010281:Parathyroid Hormone; D010710:Phosphates; D016226:Phosphorus, Dietary; D010758:Phosphorus; D002118:Calcium