Minerals Bio 1 (Minerals) PDF

Absorption, Metabolism, & Regulation of Selenium ◼ Most Se enters blood ◼ Incorporated into selenomethionine is present in soyabean and is absorbed easier than Selenite which is inorganic form. ◼ Makes selenoproteins (any protein contain selenocysteine residue e.g selenopro...

Absorption, Metabolism, & Regulation of Selenium ◼ Most Se enters blood ◼ Incorporated into selenomethionine is present in soyabean and is absorbed easier than Selenite which is inorganic form. ◼ Makes selenoproteins (any protein contain selenocysteine residue e.g selenoprotein P) ◼ Stored in muscles ◼ Maintenance of Se through excretion in urine Functions of Selenium ◼ Component of glutathione peroxidase ◼ catalyzes removal of hydrogen peroxide GSH + H2O2 GSSG + H2O ◼ Component of iodothyronine-5’- deiodinase ◼ Converts T4 to T3 ◼ Improves killing ability of neutrophils ◼ Protects cells from autooxidative damage with vitamin E Selenium Deficiency ◼ Deficiencies ◼ White muscle disease ◼ Skeletal and cardiac myopathies ◼ Keshan disease (Cardiomyopathy with heart failure) Selenium Toxicity ◼ Range between minimum requirement and maximum tolerable level is narrow ◼ Supplementation must be done with care! ◼ FDA regulations allow two forms of inorganic Se (Na selenite and Na selenate) to be used ◼ 0.3 mg of supplemental Se/kg of DM is maximum ◼ Organic form available Selenium Toxicity ◼ Toxicity ◼ Garlic-like odor of breath ◼ Nausea ◼ Vomiting ◼ Diarrhea ◼ Brittleness of teeth & fingernails Chromium (Cr): Dietary Sources, Bioavailability, & Regulation ◼ Food content depends on soil ◼ Whole grains, fruits/veg, processed meats, beer, wine ◼ Transported in blood to liver ◼ Excess excreted in urine & feces Functions of Chromium ◼ Act only together with insulin to promote glucose utilization. ◼ Growth & development ◼ Ergogenic aid (any external influences that can be determined to enhance performance in high- intensity exercises) ◼ Chromium picolinate for muscle mass Chromium Deficiency & Toxicity ◼ Deficiency ◼ Elevated blood glucose (increased insulin breakdown – impairment of glucose utilization by tissue) ◼ Decreased insulin sensitivity ◼ Weight loss ◼ Toxicity ◼ Rare ◼ Industrially released chromium Manganese (Mn): Dietary Sources & Regulation ◼ Whole grains, pineapples, nuts, legumes, dark green leafy vegetables, water ◼