The acute effects of milk intake on calcium homeostasis and cardiovascular outcome: A randomized crossover trial in postmenopausal women.

OBJECTIVE

The importance of calcium intake from dairy in regard to cardiovascular health has been investigated in several studies with discrepant results. Hence, we aim to investigate the immediate effects of milk intake on cardiovascular function.

DESIGN

A randomized crossover study with at least 10 days for washout between the two interventions, 500 ml of water with 200 µg of cholecalciferol or 500 ml of semi-skimmed milk containing approximately 600 mg of calcium with 200 µg of cholecalciferol.

PATIENTS

Twenty community-based postmenopausal women aged 60-80 years.

MEASUREMENTS

Parathyroid hormone and ionized calcium were measured at baseline and after 2 and 4 h on each study day. Pulse wave analysis and velocity were measured at baseline and after 4 h on each study day.

RESULTS

Compared to water, milk intake increased ionized calcium levels by 0.02 mmol/L (p = .029) and decreased parathyroid hormone levels by 1.78 pmol/L (p < .001). The two interventions caused no changes as measured 4 h after the intervention in the following indices of cardiovascular health; pulse wave velocity, brachial diastolic or systolic blood pressure, central diastolic or systolic blood pressure, mean arterial pressure, pulse pressure, augmentation pressure, augmentation index, heart rate or pulse transit time.

CONCLUSIONS

Despite significant changes in calcium homeostasis with increased levels of ionized calcium following milk intake, no acute effects seem to occur on measures of cardiovascular health.