Comparison of intrinsic and extrinsic tracer methods for estimating calcium bioavailability to rats from dairy foods

Journal Article · Tue Jan 31 23:00:00 EST 1989 · J. Nutr.; (United States)

OSTI ID:6279255

Buchowski, M S; Sowizral, K C; Lengemann, F W; Van Campen, D; Miller, D D

Dairy products doubly labeled with 45Ca and 47Ca were used to evaluate an extrinsic labeling procedure for calcium bioavailability determination. Nonfat milk, yogurt, and fresh cheese curd were prepared from caprine milk that was intrinsically labeled with 45Ca. The products were then labeled extrinsically with 47Ca and administered to rats by gavage. The 47Ca to 45Ca ratio in bone and teeth averaged about 1.00 with either milk, yogurt, or CaCl2, but the ratio was about 1.04 when dosed with cheese curd. Ca absorption, determined by whole-body counting of 47Ca, was lower (P less than 0.05) in cheese curd (59%) than in either milk (69%), yogurt (72%), or CaCl2 (72%). Expressed as percent of dose, the absorption of 47Ca was highly correlated with bone 47Ca (r = 0.973) and with bone 45Ca (r = 0.946). Correlation between tibia 47Ca and tibia 45Ca was r = 0.923. For the dairy products tested, our results indicated that extrinsic 47Ca was absorbed similarly to intrinsic 45Ca. Moreover, the percent of radioactive dose retained in bone appears to be a valid indicator of relative bioavailability of food Ca.

• Research Organization: Cornell Univ., Ithaca (USA)
• OSTI ID: 6279255
• Journal Information: J. Nutr.; (United States), Journal Name: J. Nutr.; (United States) Vol. 119:2; ISSN JONUA
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ABSORPTION
ALKALINE EARTH ISOTOPES
ALKALINE EARTH METALS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL AVAILABILITY
BIOLOGICAL MATERIALS
BODY
BODY FLUIDS
CALCIUM
CALCIUM 45
CALCIUM 47
CALCIUM ISOTOPES
CHEESE
COMPARATIVE EVALUATIONS
COUNTING TECHNIQUES
DAYS LIVING RADIOISOTOPES
DIGESTIVE SYSTEM
DOMESTIC ANIMALS
DOUBLE LABELLING
ELEMENTS
EVEN-ODD NUCLEI
FOOD
GOATS
INTERMEDIATE MASS NUCLEI
INTESTINAL ABSORPTION
ISOTOPE APPLICATIONS
ISOTOPE RATIO
ISOTOPES
LABELLING
MAMMALS
MATERIALS
METALS
MILK
MILK PRODUCTS
NUCLEI
NUTRITION
ORAL CAVITY
ORGANS
RADIOISOTOPES
RATS
RETENTION
RODENTS
RUMINANTS
SKELETON
SOLUBILITY
TEETH
TRACER TECHNIQUES
UPTAKE
VERTEBRATES
WHOLE-BODY COUNTING