Effect of Nutrition on Bone Metabolism as Assessed by 41Ca

Inclusion Criteria:

1. Healthy as assessed by the

   • health and lifestyle questionnaire,
   • physical examination
   • results of the pre-study laboratory tests
2. Females aged 50-68 years at Day 01 of the study
3. Relatively low calcium intake as assessed by dairy intake questionnaire
4. Body Mass Index (BMI) < 30 kg/m2
5. Postmenopausal as confirmed by Follicle stimulating hormone (FSH) and oestradiol (E2) blood levels (FSH > 40IU/L, E2 < 70 pg/mL)
6. Normal Dutch eating habits
7. Voluntary participation
8. Having given written informed consent
9. Willing to comply with the study procedures
10. Appropriate veins for blood sampling/cannula insertion according to TNO
11. Willing to accept use of all nameless data, including publication, and the confidential use and storage of all data for at least 15 years
12. Willing to accept the disclosure of the financial benefit of participation in the study to the authorities concerned.

Exclusion Criteria:

1. Participation in any clinical trial including blood sampling and/or administration of substances up to 90 days before Day 01 of this study
2. Participation in any non-invasive clinical trial up to 30 days before Day 01 of this study, including no blood sampling and/or oral, intravenous, inhalatory administration of substances
3. Having a history of medical or surgical events that may significantly affect the study outcome, including cardiovascular disease or hypertension and gastrointestinal disease
4. Prescribed medication, including hormone replacement therapy (within 6 months before start of the study) and anticoagulant medication.
5. Reported intolerance for dairy products
6. Not willing to stop the use of Boerenkarnemelk and cheese of the following Dutch brands: Emmenthaler, Gruyere, Leer/Maasdammer
7. Alcohol consumption > 21 units/week
8. Not willing to stop use of supplements containing minerals or vitamins
9. Reported unexplained weight loss or gain of > 2 kg in the month prior to the pre-study screening
10. Reported slimming or medically prescribed diet
11. Reported vegan, vegetarian or macrobiotic
12. Recent blood donation (<1 month prior to the start of the study)
13. Not willing to give up blood donation during the study.
14. Personnel of TNO Quality of Life, their partner and their first and second degree relatives
15. Not having a general practitioner
16. Not willing to accept information-transfer concerning participation in the study, or information regarding her health, like laboratory results, findings at anamnesis or physical examination and eventual adverse events to and from her general practitioner.