The Impact of Different Amounts of Calcium Intake on Bone Mass and Arterial Calcification in Ovariectomized Rats

Abstract

SummaryReduced estrogen secretion and low calcium (Ca) intake are risk factors for bone loss and arterial calcification in female rodents. To evaluate the effects of Ca intake at different amounts on bone mass changes and arterial calcification, 8-wk-old female Wistar rats were randomly placed in ovariectomized (OVX) control and OVX with vitamin D3 plus nicotine (VDN) treatment groups. The OVX with VDN rats were then divided into six groups to receive different amounts of Ca in their diets: 0.01%, 0.1%, 0.3%, 0.6%, 1.2%, or 2.4% Ca. After 8 wk of administration, low Ca intake groups with 0.01% and 0.1% Ca diets had significantly reduced bone mineral density (BMD) and bone mechanical properties as compared with those of the other groups, whereas high Ca intake groups with 1.2% and 2.4% Ca diets showed no differences as compared with the 0.6% Ca intake group. For both the 0.01% and 2.4% Ca intake groups, Ca levels in their thoracic arteries were significantly higher as compared with those of the 0.6% Ca diet group, and that was highly correlated with serum PTH levels. An increase in relative BMP-2 mRNA expression in the arterial tissues of the 0.01% and 2.4% Ca diet groups was also observed. These results suggested that extremely low Ca intake during periods of estrogen deficiency may be a possible risk for the complications of reduced BMD and arterial calcification and that extremely high Ca intake may promote arterial calcification with no changes in BMD.

The Effect of the Supplementation of a Diet Low in Calcium and Phosphorus with Either Sheep Milk or Cow Milk on the Physical and Mechanical Characteristics of Bone using A Rat Model

“…The reduction in Ca that was used in the work of Viguet-Carrin et al [ 21 ] represented a decrease in the Ca content of the diet of around 60%; however, no data on specific Ca intake were provided by the authors. There are a handful of studies that show a similar level of Ca restriction compared to our study, for example, Agata et al [ 22 ]. Agata et al [ 22 ] showed that a Ca intake of below 0.3% (representing a 50% decrease in comparison to the control) resulted in a significant reduction in BMD of the tibia.…”

“…There are a handful of studies that show a similar level of Ca restriction compared to our study, for example, Agata et al [ 22 ]. Agata et al [ 22 ] showed that a Ca intake of below 0.3% (representing a 50% decrease in comparison to the control) resulted in a significant reduction in BMD of the tibia. Our study is unique in the context of the literature due to a restriction of P intake, which did not occur in any of the above studies [ 1 , 21 , 22 ].…”

Antiosteoporotic effect of icariin in ovariectomized rats is mediated via the Wnt/β-catenin pathway

“…The main index for evaluating the effect of treatments on postmenopausal osteoporosis (POP) is the increase in BMD. Estrogen deficiency, in both OVX rats and in postmenopausal women, can lead to a reduction in BMD ( 14 , 15 ). In the present study, treatment with ICA significantly improved BMD and effectively prevented the loss of bone mass caused by the OVX-induced lack of estrogen.…”

Do Dairy Minerals Have a Positive Effect on Bone Health?

“…Differences in both the assays used, for example, animal models, cell culture systems, and human trials, and the milk components (whole milk or a fraction of milk) investigated, can lead to variable outcomes in the assessment of the effect of milk on bone health. For example, a range of metrics such as break force, mineral composition, and microstructure can be used to assess the effects of samples on bone density or bone fracture risk (Agata et al., ; Weaver et al., ), resulting in different outcomes. Confounding factors such as the milk fraction used, heat treatment, and enzymatic and microbial effects during milk processing can result in subtle changes in variables such as mineral solubility, protein functionality, and lipid oxidation (El Zubeir, Basher, Alameen, Mohammed, & Shuiep, ; Ibrahem & El Zubeir, ).…”