Involvement of Calcium and Vitamin C in Type 2 Diabetes

Abstract

The diabetes type 2 or diabetes mellitus (type 2DM) is an increasing at a frightening rate both national level and worldwide, with more than 3 million new cases per year diagnosed in the United States alone. Diabetes is the third leading cause of death in the United States, and it is also a major cause of significant morbidity. Although our current methods of treating type 2 DM and its complications have improved, prevention of the disease is preferable. Indeed, epidemiology suggest that 4 out of 5 cases of type 2 DM could be attributed to habits and forms of the modifiable behavior like obesity, sedentary lifestyle, unhealthy eating habits, family history and genetics, high blood pressure and high cholesterol. Although weight loss has been shown to be successful in delaying diabetes type 2, it is difficult to achieve and maintain for long term. Therefore, identification of environmental and easily modified risk factors is needed to prevent development of diabetes type 2. The major and most well-known function of vitamin C is to maintain calcium and potassium homeostasis and promote bone mineralization. However, recent evidence suggests that vitamin C and calcium homeostasis may also be important for a variety of non-skeletal outcomes and provide neutralizing oxygen free radicals in the body. Based on basic studies, vitamin C and calcium have also been suspected as modifiers of diabetes risk. More recently, there is accumulating evidence to suggest that altered vitamin C and calcium homeostasis may also play a role in the growth of diabetes type 2. The purpose of our systematic review was to examine: 1) the association between vitamin C & calcium status and risk of diabetes type 2. 2) The effect of vitamin C and calcium supplementation on glucose metabolism 1. Over 99% of total body calcium is found in bones and teeth, where it functions as a key structural element. The remaining body calcium functions in metabolism, serving as a signal for vital physiological processes, including vascular contraction, blood clotting, muscle contraction and nerve transmission. Inadequate intakes of Calcium have been associated with increased risk 2 of osteoporosis, nephrolithiasis, insulin resistance and obesity. Most of these disorders have treatments but no cures. Calcium is unique among nutrients (WHO 2006). Insulin not only moves glucose into the cells, but it also escorts Vitamin C. Blood sugar hogs the seats on the bus in most diabetics, therefore reducing the amount of Vitamin C can absorbed 3. Calcium: Ca 2+ ion is a highly versatile intracellular signal that can regulate many different cellular functions 4, 5. to achieve this versatility, the Ca 2+ signaling system operates in many different ways to regulate cellular processes that functions over a wide dynamic range. At the synaptic junction, Ca 2+ triggers exocytosis within microseconds, whereas at the other end of the scale Ca 2+ has to operate over minutes to hours to drive events such as gene transcription and cell proliferation. One of the challenges is to understand how these widely different Ca 2+ signaling systems can be set up to control so many divergent cellular processes. Cytosolic free calcium concentration controlled by fluxes across the plasma membrane and from intracellular stores, regulates myriad cellular functions 6 , 7 it has been established that elevated cytosolic Ca 2+ concentration is the primary trigger for insulin release. However, reduced Ca 2+ concentration in the lumen of acidic a compartment was also shown to inhibit exocytosis in the INS-1 ß-cell line. Indeed, insulin is released from pancreatic secretory ß-cells, both under basal condition and in response to glucose secretion is defective in type 2 diabetes 8, 9 .