Using Ca-41 Methodology to Assess the Impact of Different Vitamin D Supplementation Levels on Postmenopausal Bone Health
Using Ca-41 Methodology to Assess the Impact of Different Vitamin D Supplementation Levels on Postmenopausal Bone Health
The purpose of this study is to determine whether increasing levels of serum 25(OH)Vitamin D
 as achieved by oral supplementation higher than the current recommendations are associated
 with a less negative bone calcium balance in post-menopausal Swiss women.
In a substudy - not related to the vitamin D intervention - spot and 24 h urine samples are
 compared with regard to the assessment of iodine status in Swiss post-menopausal women.

 In an short subsequent study using five of the subjects who participated in the original
 trial, the effect of a 40 d-exercise program (rebounding on a trampoline) on Ca-41 excretion
 will be observed.
Inclusion Criteria:

 -  apparently healthy women, at least 5 years post-menopausal

 -  BMI 18-30

 -  no HRT

 -  no regular intake of Ca or vit D supplements

 -  wiling and able to give written informed consent and to understand, participate and
 comply with study requirements

 -  non-smokers

 -  no long travels (>3 wk) planned within study period

 Exclusion Criteria:

 -  diseases that predispose to osteoporosis

 -  history of fragility fractures

 -  currently on a weight reduction program

 -  excessive physical activity

 -  diseases influencing calcium metabolism (thyroid, parathyroid, adrenal disorders etc.)

 -  regular intake of medication affecting calcium metabolism

 -  osteoporosis (T-score below -2.5)

 -  history of psychological illness likely to interfere with the subject's ability to
 understand the requirements of the study

 -  participation in concurrent studies