BIOAVAILABILITY OF CALCIUM OF FRESH CHEESES, ENTERAL FOOD AND MINERAL-WATER - A STUDY WITH STABLE CALCIUM ISOTOPES IN YOUNG-ADULT WOMEN

True fractional Ca absorption from six foods was measured in twelve no rmal healthy,women, aged 20-29 years. The tested foods were commercial ly available fresh cheese, fresh cheese prepared by new technology and rich in Ca, similar cheese with added Fe, enteral food, mineral water alone and combined with a spaghetti meal, The aim of the study was to investigate: (1) Ca absorption from a new Ca-rich fresh cheese and to compare it with that from the traditional commercial type of fresh ch eese; (2) the effect of Fe enrichment of the new cheese on Ca absorpti on; (3) Ca absorption from the mineral water and the enteral product a nd to compare it with that from the dairy products; (4) the effect of a meal combined with the mineral water on Ca absorption, All test food s were consumed by all subjects according to a design with two Latin s quares, Each treatment of 2 d was followed by a wash-out period of 2 w eeks, Ca absorption was measured using a double stable-isotope (Ca-44 and Ca-48) extrinsic labelling technique. Mean fractional Ca absorptio n from the new fresh cheese was not significantly different from that from the traditional type (37.7 (SD 10.2)% v. 42.2 (SD 11.6)%). The ad dition of Fe to the new cheese did not significantly influence Ca abso rption, Ca-absorption values from the mineral water (37.0 (so 9.8)%) a nd from the enteral product (42.6 (SD 11.4)%) were not significantly d ifferent from those from the dairy products (37.7-42.2%, SD 10.2-11.6% ). The co-ingestion of a spaghetti meal with the mineral water signifi cantly enhanced Ca absorption from 37 (SD 9.8)% to 46.1 (SD 11.7)%. It is concluded that a new process leading to a fresh cheese with a high er Ca concentration does not alter Ca bioavailability compared with th e standard technology and for a constant Ca supply, Thus this new fres h cheese would probably provide more Ca than the standard one, The fra ctional Ca-absorption values for mineral water and the enteral product indicate that these products can make an interesting contribution to Ca supply for populations with a low Ca intake and patients with speci fic diseases respectively.