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.