title: Calcium bioavailability and parathyroid hormone acute changes after oral intake of dairy and nondairy products in healthy volunteers.
abstract: This study was designed to compare calcium bioavailability and serum parathyroid hormone acute changes after oral intake of 500 mg of elemental calcium from liquid milk, yogurt, calcium-citrate-enriched powdered milk or a calcium carbonate pill; or after intake of soybean imitation-milk. After a 12-h fast, blood samples were drawn both at baseline and 1, 2, 3 and 4 h after an oral intake of the above-mentioned products, which were ingested together with a light neutral breakfast. The administration order of the study products was randomly assigned to each of 19 healthy young volunteers (11 females, 8 males). The baseline serum concentrations of ionized calcium, phosphorus and intact parathyroid hormone (iPTH) were normal. Calcium-citrate-enriched powdered milk induced a significant increase in serum ionized calcium (p<0.001) and a significant and continuous decrease in serum iPTH concentration (p<0. 001). Yogurt and the calcium carbonate pill induced a similar but less significant effect, increasing serum ionized calcium (p<0.05) and decreasing serum iPTH (p<0.01). Liquid milk only induced a significant change in serum ionized calcium and iPTH concentration during the first 2 h; this effect was lost during the following 2 h. In conclusion, our study suggests the possibility that the addition of calcium citrate to powered milk may improve calcium bioavailability and enhance the inhibitory effect on serum iPTH in the assayed conditions.
authors.affiliation: IDIM Metabolic Research Institute, Del Salvador University, Buenos Aires, Argentina.
authors.forename: J R
authors.initials: JR
authors.lastname: Talbot
authors.forename: P
authors.initials: P
authors.lastname: Guardo
authors.forename: S
authors.initials: S
authors.lastname: Seccia
authors.forename: L
authors.initials: L
authors.lastname: Gear
authors.forename: D R
authors.initials: DR
authors.lastname: Lubary
authors.forename: G
authors.initials: G
authors.lastname: Saad
authors.forename: M L
authors.initials: ML
authors.lastname: Roberts
authors.forename: E
authors.initials: E
authors.lastname: Fradinger
authors.forename: A
authors.initials: A
authors.lastname: Marino
authors.forename: J R
authors.initials: JR
authors.lastname: Zanchetta
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001682:Biological Availability; D002136:Calcium, Dietary / Q000097:blood / Q000493:pharmacokinetics*; D003611:Dairy Products; D005260:Female; D006801:Humans; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood*
chemical_list: D002136:Calcium, Dietary; D010281:Parathyroid Hormone