Calcium Absorption and Retention From Marine Products
Information source: University of Copenhagen
Information obtained from ClinicalTrials.gov on June 20, 2008
Link to the current ClinicalTrials.gov record.
Condition(s) targeted: Calcium Metabolism
Intervention: Calcium controlled diet (Behavioral)
Status: Active, not recruiting
Sponsored by: University of Copenhagen
Official(s) and/or principal investigator(s):
Susanne Bügel, MSc, PhD, Principal Investigator, Affiliation: Institute of Human Nutrition, THe Royal Veterinary and Agricultural University, Denmark
The purpose of the study is to determine the uptake of calcium from fish bone meal from
salmon and cod in 12 healthy volunteers. A test meal labelled with trace amounts of a
readioactive calcium isotope (Ca47) will be given after an overnight fast and whole body
retention of calcium will be measured on day 13, 21, and 24 after the test meal day.
Official title: Calcium Absorption and Retention From Marine Products
Study design: Prevention, Randomized, Double-Blind, Active Control, Crossover Assignment, Bio-availability Study
Primary outcome: Whole body retention of calcium
Secondary outcome: D-vitamin and PTH status, serum calcium and phosporus, and calcium intake
Up till now little attention has been given the exploitation of marine by-products from the
fishing industry. Calcium in fish is found mainly in bone and skin. By-products from these
sources are limited to production of gelatine. Small fish, which can be eaten whole with
bones included, are traditionally considered to be a good source of calcium. Until recently,
bioavailability of this calcium was not known. Two recent studies from Denmark have shown
that the absorption of calcium from small soft-boned fish was comparable to that of skimmed
milk both in rats and in humans.
Calcium fortified foods are likely to play an important role in helping consumers to achieve
calcium requirements aimed at reducing the risk of developing osteoporosis. Experimental
evidence show a positive effect of calcium supplementation on bone mineral accretion in
children, and combined calcium and vitamin D supplementation has resulted in reduced bone
loss and fracture incidence in older men and women.
This protocol describes a project on the nutritional utilisation of calcium from fish bone
waste. The main objective is to maximise the use and the added value of marine by-products
with special emphasis on utilisation of fish bone as a calcium source and determine its
bioavailabiliy in humans.
Study design :
This study will follow a 3x7 weeks ransomised crossover design, where the calcium absorption
and retention will be measured form meals labelled with 47Ca. The test meals will be digested
in the morning after a 12h fast and bloodsampling. Whole body retention will be measured on
day 15, 22 and 26, and calibrated against a background measurement from the day prior to
ingestion of the test meal. The subjects will receive an ordinary standardised diet for 2
days prior and 3 days after the test meals. This diet will be standardised to match the
subjects' individual calcium intake.
Two types of fish bone meal (from salmon and cod fish) and a control (CaCO3) will be tested.
Amounts equivalent of 800 mg Ca will be baked into bread, which will be labelled with 47Ca
and served with 500 mL of ultra pure water at the department.
Isotopes and labelling procedure:
Isotopes (47Ca) will be ordered from Risø National Laboratory, Radiation Research Department,
Denmark. The department of Human Nutrition will recieve the prepared doses of isotopes the
day before the test meal. A dose of 0. 2 MBq/ml will be used. The doses will be used to
extrinsically label the test meals by drop-wise adding 1 ml of isotope solution in the
afternoon on the day before intake of test meals and stored at 5 degree C until ingested.
Since each subject will recieve labelled meals on three occasions, a total dose of 0. 6 MBq
will be ingested during the study.
Measurement of calcium retention:
The whole body retention of calcium will be measured with a whole body counter at the
Copenhagen University Hospital, Denmark. All measurements of calcium retention will be
corrected for physical decay back to the time of administration.
Serun calcium, phosphorus and vitamin D concentrations will be determined in before each test
meal. Plasma levels of PTH will be determined before the first test meal only.
Minimum age: 18 Years.
Maximum age: 40 Years.
- healthy males
- BMI: 18-18 kg/m2
- age: 18-40 years
- elite athletes
- on medication
- gastrointestinal disorders, chronic diseaes
- prior participation in radioisotpe studies
Locations and Contacts
Institute of Human Nutirtion, The Royal Veterinary and Agricultural University, Denmark, Frederiksberg, Frederiksberg C 1958, Denmark
Starting date: November 2005
Ending date: March 2006
Last updated: October 26, 2006