| Question | Answer |
| Vitamin E is also called | Tocopherol |
| form of vitamin E absorbed by the human body | Alpha-tocopherol |
| Vitamin E deficiency in newborns | hemolytic anemia |
| In children, vitamin D deficiency can result | rickets |
| In adults, vitamin D deficiency --> | Osteomalacia |
| Principle function of vitamin D | maintain levels of calcium and phosphorus in the blood to favor bone mineralization |
| fat soluble vitamins include... | A, D, E, K |
| fat soluble vitamins require ? to be absorbed | bile & dietary fat |
| vitamin A plays role in _____ | night vision, cell differentiation, growth regulation |
| Preformed vitamin A compounds= | retinoid |
| Plants contain precursors to vitamin A = | carotenoid |
| what has activity of vitamin A? | retinoid: (retinol, retinal, retinoic acid)
-Beta carotenoid does NOT have activity (can be converted) |
| Retinoids and carotenoids are transported from the intestine in | chylomicrons
(then delivered to liver) |
| in liver, some carotenoids converted to | retinol |
| vitamin A form that circulates in blood | retinol |
| vitamin A form important for vision | retinal |
| vitamin A form used for modulating gene expression | retinoic acid |
| retinoic acid formed from | retinal (but no converting back!) |
| Carotenoids that are not converted to vitamin A may act as | antioxidants |
| in eye, retinal combines with _____ to form _____ | combines with OPSIN to form RHODOPSIN |
| rhodopsin function | transform the energy from light into a nerve impulse that is sent to the brain (interprets as vision) |
| rhodopsin embedded in ____ cells | rod |
| vitamin A & gene expression | retinoic acid enters nucleus, binds to specific protein receptors
-RA receptor binds to regulatory region on DNA
--> alters level of mRNA produced |
| The genes that are regulated by RA involved in.... | growth and development, embryogenesis and the IMMUNE system |
| vitamin A deficiency caused by | insufficient intake of vitamin A, fat, protein or zinc
--> major cause of blindness |
| Foods natural sources of vitamin D | liver, fatty fish, fish oils and egg yolks |
| Vitamin D is important for..... | bone health, normal functioning of the parathyroid gland and regulation of the immune system. |
| blood calcium level drop stimulates.... | parathyroid gland releases parathyroid hormone (PTH)
--> kidney to activate enzymes to convert 25-hydroxyvitamin D3 to active form, 1,25-hydroxyvitamin D3 |
| actions of vitamin D for bone health | -increase calcium transport proteins in intestines (move Ca from intestine to body)
-in bones, stimulate release of Ca by bone breakdown
-in kidney, increase amount of Ca retained by kidneys and put back into the blood |
| types of genes that vitamin D regulates | genes regulating bone health, immune response, reproductive functions, and skin growth. |
| though rare, individuals at risk for vitamin E deficiency are... | premature infants, individuals with fat malabsorption, protein malnutrition, inherited abnormalities in vitamin E metabolism
-newborns w/ low blood tocopherol |
| Vitamin K was named for.... | Koagulation (danish for coagulation) |
| vitamin K forms | phylloquinone and menaquinones |
| vitamin K in diet | -phylloquinone in plants (leafy green vegetables)
-menaquinones in fish oil, meats and synthesized by bacteria in the human intestine |
| vitamin K functions in body | -blood clotting
-Involved in proteins needed for bone mineralization and demineralization |
| vitamin K deficiency results in _____ and is common in _________ | -results in abnormal blood coagulation
-common in newborns (little transfer to fetus by mother, low vitamin K in breast milk)
-infants given vitamin K injection right after birth |
| retinoids & cartenoids transportation | from intestine in chylomicrons --> to body tissues (bone marrow, blood cells, spleen, liver, kidney, muscles) |
| some cartenoids converted to ______ in ___________ | converted to RETINOL in LIVER |
| move retinol from liver to tissues..... | retinol must bind to RETINOL-BINDING PROTEIN |
| vitamin D from sunlight/ food --> active form | • Enzymes in LIVER add hydroxyl group (-OH) to carbon #25
• Enzymes in KIDNEY add –OH to carbon #1 → active vitamin D: 1,25 dehydroxy Vitamin D |
| low Vitamin D level --> | increase calcium absorption from INTESTINE |
| high Vitamin D level --> | stimulate PTH increase bone breakdown; stimulates kidney to activate enzymes convert 25-hydroxyvitamin D3 to ACTIVE form; KIDNEY increase calcium retention |
| active vitamin D functions | • Active vitamin D binds Vitamin D receptor proteins @ target tissues → affect gene expression
o Increase blood calcium levels
o Targets= intestinal cells, bone, kidney |
| vitamin D deficiency | rickets (children), osteomalacia (adults) |
| where vitamin E works as antioxidant | cell membranes, body proteins, DNA, cholesterol |
| how vitamin E works as antioxidant | DONATES e- to eliminate free radicals, Vitamin C restores antioxidant functions (gives back e-) |
| why infants need shot of vitamin K | • Little transfer to fetus, breast milk low in vitamin K, and no bacteria in newborn gut (to synthesize vitamin K) |
| vitamin K shot prevents.... | uncontrolled bleeding |
