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

Journal Article · Wed Feb 01 00:00:00 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), Vol. 119:2
• Country of Publication: United States
• Language: English

Related Subjects

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