The process of bone remodeling exhibits pronounced diurnal pattern that is important for bone health. A balanced rate of bone resorption is required to maintain bone health, a balance that can be disturbed during the lifecycle to effect net rate of formation (as occurs during growth and development to adulthood) or net resorption (as occurs, for example, during the menopause).The research to be undertaken investigates the pluripotent effect of dairy-based products on the regulation of the diurnal process of bone metabolism in post-menopausal women at risk of osteoporosis.

Study Design: A block randomised, cross-over design of 24h rates of bone turnover in healthy, post-menopausal women with osteopenia receiving either a milk-based protein supplement (MBPS) or isoenergetic placebo control (PLACEBO).

Participants: 16 Post-menopausal women with osteopenia as determined by site-specific bone mineral density BMD (DXA) diagnosed and screened by a clinician and for dietary intake of calcium and Vit D by a clinical dietitian.

Subject screening (clinical examination) and dietary intake of calcium and Vit D (by food frequency questionnaire) will precede the experimental protocol.

Experimental protocol and data collection:

Subjects will attend for a 2 day and 2 night (overnight) residence equipped to conduct residential human trials.

The subjects' programmed protocol is as follows;

1. Arrive @ 17:00h with overnight bag;
2. Empty bladder and then provide and retain urine samples for the duration of the stay (assisted collection by researchers);
3. Consume a standardised evening meal (pre-prepared by the research dietitian) and then relax reading/watching films etc;
4. At 20:00h a research nurse will insert a cannula into a superficial arm vein and a blood draw (5ml) will be taken and processed for later analysis;
5. Further blood draws (5ml) will be taken at 22:00h, 2300h, 2400h,0100h and 0200h and the cannula withdrawn;
6. At 22:00h consume either placebo control (PLACEBO) (day 1) OR supplement (MBPM)(day 2) - or vice versa - in randomised order.
7. Retire to bedroom;
8. Consume a standardised breakfast and lunch (pre-prepared by the research dietitian) whilst living in and around the University grounds (i.e. in close proximity to ensure 24h urine collection is complete);
9. Repeat from 2 above to end of 2nd day.

Inclusion Criteria:

Post-menopausal women aged 50-70y. Assessed by site-specific BMD to be osteopenic. Assessed by clinical screen to be otherwise healthy and free from other illness or current medication likely to influence the study outcome.

Exclusion Criteria:

Intolerance to dairy-based food products

Single blind (participant only)