Dairy Calcium Intake and Relationship to Bone Mineral Density (BMD), Bone Mineral Content (BMC) and Leptin in Post- Menopausal Women

Previous research has demonstrated that dairy calcium along with calorie restriction can contribute to
weight loss while maintaining BMC and BMD. This study was a 3-month demonstration of a culturally
sensitive program to evaluate the effects of dairy calcium.
Caloric intake was limited to 1400 kcal/d [@ 92% of resting energy expenditure]. A total of 56 female
subjects were randomized into two equal groups receiving either low dairy calcium ~800 mg/d or high
dairy calcium ~1400 mg/d intake. The age and body mass index (BMI) at baseline for the low calcium
group was 54.46±7.39 years, 32.5±6.6 kg/m2 respectively; and the high calcium group was 56.75±
8.90 years, 33.5±5.8 kg/m2 respectively. Differences after 3 months in weight, BMI, leptin, BMD and
BMC were analyzed. Correlations were calculated between leptin and BMD (g/cm2) or BMC (g) before
and after intervention. After the intervention in the high calcium group there was an average reduction
in weight -1.52±2.08 (kg), (P=0.001); BMI: -0.70±0.86 kg/m2, (p<0.001); leptin: -1.18±5.10 ng/ml, (P
=0.231) BMC: -0.009±1.41, (p=0.975) and BMD: 0.001±.017, (p=0.684). Despite a greater reduction
in leptin levels in the low calcium group, changes in all parameters were not different from changes in
the low calcium group with an average reduction in weight of -1.93±3.04 (kg), (p=0.002); BMI: -
0.74±1.2 kg/m2, (P=0.002); leptin: -2.58±8.38 ng/ml, (P=0.114), BMC: 0.038±1.38, (P=0.887) and
BMD: <0.001±.022, (P=0.912). The decrease in leptin level was not correlated with BMD and BMC in
both intervention groups (all P>0.05). We observed a significant treatment effect only for leptin where
the low calcium group had a bigger reduction compared to the high calcium group. There was no
significant correlation between the change in leptin, BMC and BMD. After the intervention, there was
significant reduction in weight, BMI, and leptin in both intervention groups and a non-significant
increase in BMC and BMD. There was no correlation between leptin, BMC and BMD. We should take
note that this study had a limited sample size and short follow-up period. Nonetheless, based on
these findings, we would suggest, that since postmenopausal women have age related bone loss, in
addition to a restricted calorie diet (i.e. 1400 kcal/day), the inclusion of increased ≥ 4 servings of low
fat dairy to one’s diet for weight management.