EFFECT OF DIETARY CALCIUM IN ADULTS

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 研究表明，细胞内钙(Ca)是人体脂肪代谢的调节因子。细胞内钙的增加会导致脂肪储存的增加和脂肪利用率的下降。调节脂肪细胞内钙的方法可能成为预防和/或治疗肥胖的新策略。维生素D的活性形式，骨化三醇，刺激细胞内钙的增加。通过抑制骨化三醇，细胞内的钙会减少，从而增加脂肪的利用。导致骨化三醇抑制的一个机制是通过增加饮食中的钙。通过增加血液中细胞外钙的含量，刺激甲状腺释放降钙素，这是一种抑制骨化三醇的激素。饮食中的钙也会导致粪便中未被吸收的脂肪排出。这项研究将考察补钙和能量限制对减肥的影响。我们的目标是确定膳食钙和能量缺乏如何影响能量代谢和平衡、体重和组成以及脂肪代谢。拟议研究的具体目标是： 1.确定高钙饮食对能量代谢和平衡的影响。 2.确定高钙饮食对体重和成分的影响。 3.说明膳食钙对脂肪代谢的影响。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. It has been shown that intracellular calcium (Ca) is a regulating factor in fat metabolism in humans. Increases in intracellular Ca cause an increase in fat storage and a decrease in fat utilization. Methods to regulate intracellular Ca in fat cells may be a new strategy in the prevention and/or treatment of obesity. The active form of vitamin D, calcitriol, stimulates an increase in intracellular Ca. By suppressing calcitriol, intracellular Ca will decrease causing an increase in fat utilization. One mechanism that causes the suppression of calcitriol is by increasing dietary Ca. By increasing the amount of extracellular Ca in the blood stream, the thyroid gland is stimulated to release calcitonin, which is a hormone that suppresses calcitriol. Dietary calcium could also cause excretion of unabsorbed fat in stool. This study will examine the effect of calcium supplementation and energy restriction on weight loss. Our goal is to determine how dietary calcium in combination with energy deficit affects energy metabolism and balance, body weight and composition, and lipid metabolism. The specific aims of the proposed research are: 1. To determine how high calcium diet affects energy metabolism and balance. 2. To determine how high calcium diet affects body weight and composition. 3. To explain how dietary calcium affects lipid metabolism.