Alcohol-Induced Malabsorption in the Gastrointestinal Tract
Victor R. Preedy, Ronald R. Watson in Alcohol and the Gastrointestinal Tract, 2017
The transport of all these nutrients, with the exception of thiamine and calcium then proceeds by a "secondary active transport" mechanism. Such a process requires the cotransport of sodium which also binds to the relevant transporter protein, and the nutrients are then transported via the transmembrane electrochemical sodium gradient generated by the active transport of sodium out of the enterocyte at the basolateral membrane. In addition to this mechanism, proline may also be transported into the cell by a hydrogen-coupled, sodium-independent, active transport mechanism, while such a sodium-independent mechanism has also been proposed for glutamine. In contrast, calcium absorption may occur either by an active transport (ATP-dependent) pump or by sodium/calcium exchange.
Calcium
Linda M. Castell, Samantha J. Stear (Nottingham), Louise M. Burke in Nutritional Supplements in Sport, Exercise and Health, 2015
Adequate levels of calcium throughout life are critical to bone health although other nutrients are also important (USDHHS, 2004; IOM, 2011; Prentice, 1997). Much of the work on examining the effect of nutrition on bone health has focused on calcium and phosphorus, due to them being major constituents of bone tissue, and vitamin D due to its role in calcium absorption. Other trace elements, such as zinc, manganese and copper are necessary for growth, development and maintenance of healthy bones; whereas dietary components such as vitamin C, vitamin K, magnesium and fluoride have biological actions that are at the level of bone itself; with vitamins A and B6 also being linked to bone (Prentice, 1997). See elsewhere in the book for key topics. Other nutrients are also important due to their influence on calcium absorption. While many nutrients play a role in bone health, this article will focus on calcium and the associated role of vitamin D.
Calcium and Vitamin D
Maria A. Fiatarone Singh, John Sutton Chair in Exercise, Nutrition, and the Older Woman, 2000
Calcium absorption and excretion are influenced by a number of factors, including age, usual calcium intake level, other nutrients in the foods we eat, and medications. Absorption efficiency is greatest during periods of bone growth such as childhood, adolescence, and pregnancy and lactation when the demand for calcium is very high. However, absorption efficiency begins to decrease in middle age, and in women, a sharp drop is seen around the time of the menopause (Heaney et al., 1989). Although a greater percentage is absorbed when habitual calcium intake is low, the increase in absorption fraction cannot totally compensate for a diet that is inadequate. Other nutrients can enhance or inhibit the calcium absorption. Lactose, the sugar found in milk products, improves absorption. Oxalate and phytate, which are found in some vegetables and grains, reduce calcium availability. On balance, these nutrient interactions will not significantly affect calcium nutrition as long as the diet contains a wide variety of foods, each consumed in moderation. High dietary levels of protein, sodium, and caffeine can increase urinary calcium excretion (Kerstetter and Allen, 1990; Dawson-Hughes et al., 1996; Massey and Whiting, 1993) and some of these nutrients may have their most adverse effects when calcium intake is low.
No association between the vitamin D pathway gene polymorphisms and bone biomarkers response to calcium and low dose calcitriol supplementation in postmenopausal Chinese women: a one-year prospective study
Published in Biomarkers, 2018
Jiemei Gu, Chun Wang, Hao Zhang, Hua Yue, Weiwei Hu, Jinwei He, Wenzhen Fu, Zhenlin Zhang
Vitamin D deficiency has been recognized as a major public health problem worldwide. Oral supplementation of vitamin D3, cholecalciferol and its analogues alphacholecalciferol and calcitriol are used for the treatment of vitamin D deficiency. Calcitriol has been used as a treatment for osteoporosis for many years. Calcitriol plays a crucial role in skeletal system regulation and may have other protective effects on bone independent of its effects on calcium absorption (Richy et al. 2004). Results of several trials showed different effect of calcitriol on bone metabolism of postmenopausal women (Tjellesen et al. 1984, Caniggia et al. 1986,1990, Aloia et al. 1988, Ott and Chesnut 1989, Caniggia et al. 1990, Sairanen et al. 2000, Inanir et al. 2004).
Bioavailability of Calcium from Chia (Salvia hispanica L.) in Ovariectomized Rats Fed a High Fat Diet
Published in Journal of the American College of Nutrition, 2021
Marcella Duarte Villas Mishima, Bárbara Pereira da Silva, Renata Celi Lopes Toledo, Neuza Maria Brunoro Costa, Hércia Stampini Duarte Martino
With aging and post-menopause, the efficiency of calcium absorption is decreased. Low estrogen levels are known to induce bone remodeling and skeletal frailty, determinants of osteoporosis pathogenesis (1–3). Skeletal abnormalities such as bone loss occur when there is an imbalance in bone matrix synthesis and bone resorption, controlled by osteoblasts and osteoclasts, respectively. This imbalance is also caused by hormonal changes and inflammation (4). In this sense, bone resorption is affected by low estrogen in the postmenopausal period and inflammation induced by obesity. Consumption of a high fat diet increases inflammation (5), adipocyte hypertrophy stimulates the secretion of proinflammatory cytokines. In turn, these cytokines stimulate the differentiation of osteoclasts and bone resorption (6, 7). Recommendation of calcium intake is based on bone health since calcium is one of the main strategies to ensure bone construction and maintenance (8), thus its adequate intake is important (9).
Calcium Intake Contributed by Whole Foods and Gastric Cancer in Viet Nam: A Case‑Control Study
Published in Nutrition and Cancer, 2023
Thinh Gia Nguyen, Dung Thuy Thi Truong, Phuoc Hong Le, Tuyen Cat Kim Vo, Shunya Ikeda, Ngoan Tran Le
Many studies have shown that calcium and vitamin D intake may synergistically affect the prevention of GC. Meinrad et al. stated in their review that activation of the CaSR or the vitamin D receptor (VDR) is linked to the underlying mechanism of calcium, vitamin D, and colon mucosal cancer. It is transduced by the same essential differentiation and antiproliferative signaling components, including TCF-4, E-cadherin, c-Myc, and cyclin D1 (34). High luminal calcium restricts cellular development by activating the CaSR. In addition, it suppresses 25(OH)D-24-hydroxylase (CYP24), which catabolizes vitamin D, resulting in increased steady-state local concentrations of 1,25(OH)2D3 (35, 36). Furthermore, 1,25(OH)2D3 has been shown to upregulate CaSR expression (37) and enhance the antitumor effect of high extracellular Ca2+. Vitamin D plays an essential role in calcium absorption (38). Vitamin D may modulate the antiproliferative effect of dietary calcium by controlling serum calcium levels. In addition, high dietary calcium and vitamin D consumption may bind to free fatty acids and secondary bile acids in the digestive tract. This reduces toxicity to intestinal epithelial cells and prevents intestinal mucosa and epithelial cell growth (39). According to these findings, consuming appropriate amounts of calcium and vitamin D may lower the incidence of gastrointestinal cancers.
Related Knowledge Centers
- Bone
- Bone REModeling
- Calcium
- Extracellular Fluid
- Gastrointestinal Tract
- Metabolism
- Blood Plasma
- Kidney
- Fluid Compartments
- Calcium In Biology