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Nutrition - Vitamins
Question | Answer |
---|---|
What are the significant sources of Vitamin A? | Liver, green leafy vegetables, yellow-orange vegetables, fruit & fortified foods |
In what organ/cell does Vitamin A gets absorbed in first? As what substance? | Intestinal Lumen; Retinyl esters |
What substance from Vitamin A is released from the intestinal epithelial cells into the blood? | Retinyl esters in chylomicrons |
What substance from Vitamin A is released from the liver parachymal cells into the blood? | RBP-retinol |
What substance from Vitamin A does the liver parachymal cells release into the liver stellate cells? What does the substance eventually become? | Retinol; Retinyl esters |
What are the basic functions of Vitamin A | Vision, reproduction, immune function, cell proliferation, cell signaling, |
What form of Vitamin A is used for vision? | 11-cis-retinal |
What form of Vitamin A is used for immune function? | Retinol; mediates lymphocyte survival and proliferation |
What are the symptoms for Vitamin A deficiency? | Ocular problems and/or depressed immune function |
What are the diseases caused by Vitamin A deficiency? | Night Blindness, blindness, xerophthalmia, Keratomalacia (dry eyes,irreversible), keratinization of tracheal epithelium |
What are two signs of xerophthalmia? | Structural damage to the cornea and Bitot's spot |
What are the clinical signs and symptoms for Vitamin A toxicity? | Teratogenic effects, liver disease, dryness, erythema (redness of skin), scaling/peeling of skin, hair loss, nail problems, headache, nausea, vomitting, overgrowth of periosteal bone, and increase in bone fractures |
What are the significant sources of Vitamin D? | -Fatty fish, fish oils, fortified foods like milk, cereal, and breads -Rare in food |
Vitamin D is uptaken by what organ of the body? | Liver |
Liver converts Vitamin D to what structure? Where does this structure travel to? | 25(OH)D; Prostate gland, breast, colon, lung, immune cells, and kidney |
The kidney convert 25(OH)D to what form of Vitamin D? What is this form of Vitamin D involved with? | -1,25(OH)2D -Involved in calcium homeostasis, muscle and bone health, BP regulation, insulin production, prevention of heart disease and type 2 diabetes) |
The prostate gland, breast, colon, lung, immune cells produce what form of Vitamin D? What does this form of Vitamin D do for the body? | Regulation of immune function (prevention of type I diabetes and autoimmune disease) and regulation of cell growth (cancer prevention) |
Deficiency of Vitamin D would lead to what disease in children? Describe the disease. | Rickets; Disorganization & hypertrophy of chondrocytes at mineralization front |
Deficiency of Vitamin D would lead to what disease in adults? Describe the disease. | Osteomalacia (poor mineralization collagen matrix;osteiod), osteopenia (decrease in opacity as seen in radiographs), deep bone pain(due to hydration of unmineralized matrix in periosteum), hypocalcemia (low calcium levels), hypophosphatemia (low P lvls) |
Toxicity of Vitamin D | Hypercalcemia, hyperphosphatemia, calcification of soft tissues, constipation, polyuria, polydispia, kidney stones, headache, weakness |
Describe the absorption of Vitamin E (part 1) | -absorption and transport is similar to that of cholesterol absorption/transport -Absorption is initiated in the intestines where they are absorbed by the enteroscytes -Vitamin E and corresponding triglycerides are then incorporated into chylormicrons |
Describe the absorption of Vitamin E (part 2) | -The movement of Vitamin E throughout the lymphatic system is identical to that of cholesterol and fats. Once absorbed in the liver is incorporated into VLDLs or used to make water-soluble metabolites of vitamin E. |
Describe the absorption of Vitamin E (part 3) | Vitamin E from other cells is packaged into HDLs and transported throughout the body |
Describe Vitamin E's function as a free radical scavenger | -protect membrane lipids and proteins from free radical damage -The tocopherols donate an e- to the free radical thus removing the free radical and protecting lipids & proteins from being oxidized |
Other Vitamin E non-free radical activities | -modulate protein kinase C activity -alter cell proliferation -induce arachidonic acid synthesis |
Significant sources of Vitamin E | Oil seeds, salad dressings, mayonnaise, margarines, oils (sunflower/safflower), nuts, and various spreads are the highest sources of Vitamin E in our diet |
What has animal studies shown us about Vitamin E deficiency? | -Cardiac Myopathy in rabits &guinea pigs -Species specificity (unknown) |
Describe Vitamin E Deficiency's clinical signs, symptoms, and diseases | -Decreased life span of RBC's -Deficiencies are rare, but often present in patients with lipoprotein deficiencies, lipid malabsorption syndromes, and fat malabsorption conditions -Vitamin E is inadequately transferred across the placenta |
What do epidemiology studies say about Vitamin D Deficiency? | -Increase immune response -Decrease risk of cardiovascular disease |
Toxicity of Vitamin E | -Supplements -Increase blood coagulation time and possible risk of hemmorrhage |
Significant Sources of Vitamin K from diet | Green vegetables, kale, collards, spinach, parsley, broccoli, brussels sprouts, cabbage, and lettuce -animal products are typically a PPOR source for Vitamin K |
Describe Vitamin K (Phylloquinone) absorption | -Similar to fat absorption -transported in chylomicrons to the liver as a chylomicron remnant -found circulating in HDLs, LDLs, & VLDLs -phylloquinone is excreted primarily in the feces, but may be excreted in the urine |
Describe Vitamin K deficiency in newborns | -Secondary deficiency -normal "flora" bacteria (prod Vit K) is absent in newborns -Vit K is typically low in breast milk -Hypothrombinemia in newborns -commercial infant formula is formulated w/ Vit K -Mothers can increase vit K lvls in breast milk w |
Describe Vitamin K deficiency | -In newborns -Antibiotic consumption can induce vitamin K deficiency -Patients undergoing long term total parenteral nutrition -Malabsorption problems |
Biochemical assessment of Vitamin K | -Plasma/serum phylloquinone concentrations not typically used -Prothrombin time-an indirect test used to assess Vitamin K levels |