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Vitamins and Nutrition
Published in Richard J. Sundberg, The Chemical Century, 2017
Vitamin B12 is also known as cobalamin. Cobalamin functions as a cofactor for two critical enzymes, methionine synthase and l-methylmalonyl Co-A mutase. The former also requires folic acid and is important in biosynthesis of nucleosides. The latter converts methylmalonyl Co-A to succinoyl Co-A, which is a crucial step in metabolism of fats and in the biosynthesis of hemoglobin. The best food sources of B12 include meat, seafood, cheese, and eggs. Clams, mussels, and crabs are especially high. Plants do not produce B12 and the source in other foods is evidently the ingestion of material synthesized by bacteria. Several diseases are associated with vitamin B12 deficiency. A form of anemia, called chlorosis, because of the green palor of patients, was found to be resistant to treatment with iron. In 1892, William Oster, then at the Johns Hopkins University, noted that young women who were over-worked and poorly nourished were most likely to fall victim. The condition came to be called pernicious anemia, because it was almost always fatal. In the 1920s, George H. Whipple discovered the value of eating liver and other organs in treating dogs with experimental anemia. A Boston physician, William P. Murphy, working mainly with poor Irish patients, noticed that one of his male patients seemed to be surviving longer than usual and inquired about his diet. It turned out the man ate a lot of liver and ate it raw. Murphy turned for help to George Minot, a physician who was affiliated with a Harvard teaching hospital. They found that indeed eating raw liver improved patients and they were able to isolate an extract that had the same effect. Whipple, Murphy, and Minot received the 1934 Nobel Prize in Physiology or Medicine.
A review of public and environmental consequences of organic germanium
Published in Critical Reviews in Environmental Science and Technology, 2020
Jiangfu Zheng, Lihua Yang, Yaocheng Deng, Chenyu Zhang, Yang Zhang, Sheng Xiong, Chunxia Ding, Jia Zhao, Chanjuan Liao, Daoxin Gong
Other studies have demonstrated that low concentrations of organic germanium may play a role in improving immunity of biological system of a body through co-existing components of oligosaccharide and lactobacillus. Among them, alkyl germanium salt and aryl germanium salt are the most interesting organic germanium. Its antifungal or antibacterial effects have been studied. Their antibacterial activity is slightly lower than the corresponding organotin compounds, and their scope of application is narrow (Nakamura, Saito, & Aso, 2012; Sijpesteijn, Rijkens, Luijten, & Willemsens, 1962). Hopefully in the near future organic germanium compounds which are soluble in water will be prepared and used to treat pernicious anemia (Orndorff, Tabern, & Dennis, 1927). From 1980 to 2000, a lot of experiments have been carried out on the anticancer effect of organic germanium (Table 2).
Mechanistic links between vitamin deficiencies and diabetes mellitus: a review
Published in Egyptian Journal of Basic and Applied Sciences, 2021
Tajudeen O. Yahaya, AbdulRahman B. Yusuf, Jamilu K. Danjuma, Bello M. Usman, Yahaya M. Ishiaku
Vitamin B12, otherwise called cobalamin because it contains cobalt, is a water-soluble vitamin [28]. It is the most studied and structurally complex of the B-vitamins, and found in all cells where it is involved in DNA synthesis, optimal hemopoiesis, and neurological activities [28]. Vitamin B12 and some other B-vitamins lower homocysteine levels – an amino acid that predisposes to T2DM by promoting oxidative stress, insulin resistance, β-cell dysfunction, systemic inflammation, and endothelial dysfunction [29,30]. Depletion of vitamin B12 may lead to pernicious anemia, which is often associated with T2DM. The deficiency of vitamin B12 is also linked with autoimmune diseases, including T1DM [28]. Vitamin B12 is abundant in animal products such as meat, milk, eggs, poultry, eggs, and fish [31]. These show that individuals following vegan diets are more at risk of vitamin B12 deficiency [31]. Many studies have linked vitamin B12 deficiency with the pathogenesis of DM. In one study, vitamin B12 deficiencies in pregnant women were linked with obesity, a risk factor of both TIDM and T2DM [32]. In another study, an association was established between maternal vitamin B12 levels and risk of maternal obesity and gestational diabetes mellitus [33]. In a clinical trial, vitamin B12 therapy improved insulin resistance and endothelial function [34]. Additionally, low vitamin B12 levels were linked with an increased risk of adiposity [35]. Vitamin B12 modulates several cellular processes, particularly epigenetic changes that are necessary for gene expression. Some of these pathways may be involved in the fetal metabolic configuration that predisposes offspring to insulin resistance [32]. The mechanistic links between vitamin B12 deficiency and DM are summarized in Figure 2.