NTDT200 Exam 3 Review Questions Chapters 11 Would you be concerned if you didn t eat any fat soluble vitamins in a day No because fat soluble vitamins are stored in body tissues The body will retrieve vitamins from their stores if needed so it can take days weeks or months for deficiencies to occur An individual consumes a large amount of vitamin A food sources and his her skin turns yellow Is this clinically significant Why or Why not There are several chemical compounds that have vitamin A activity the most common of which are carotenoids of which beta carotene is most easily recognized If an individual consumes a large amount of foods that are high in beta carotene the skin may turn yellow but this is not clinically significant Betacarotene serves as a vitamin A precursor in the body and thus not all of it is converted into vitamin A It is important to note the source of vitamin A compounds since if vitamin A is provided in the form of supplements this can prove to be clinically significant Remember that vitamin A is a fat soluble vitamin and as such can be stored in the body leading to toxic levels What are the three forms of vitamin A What protein is responsible for transporting vitamin A 3 forms retinol retinal retinoic acid Retinol binding protein RBP is the protein that transports retinol What are risks associated with high doses of vitamin A What types of vitamin A can cause toxicity What groups are most vulnerable High doses of vitamin A can be toxic Excessive vitamin A may weaken bones and contribute to osteoporosis and fractures During pregnancy excess vitamin A can cause birth defects Pre formed vitamin A is the form that is concerning in terms of toxicity This can be found in supplements or certain animal derived foods Also Acutane which is made from vitamin A but chemically different is highly toxic Women of childbearing age need to be very careful about taking it because of the risk of birth defects Beta carotene which is a precursor of vitamin A can t cause toxicity Children and women are two groups that are particularly vulnerable to vitamin A toxicity Why are vitamin A supplements often given to children in developing countries Although vitamin A deficiency is not common in children in the US it s a major nutrition problem in many developing countries Approximately 250 million children worldwide have vitamin A deficiency which puts them at risk for infectious diseases and blindness Routine vitamin A supplementation can be a life saving intervention and can reduce the risk of deaths associated with infections and severe diarrhea What are the two ways people can obtain vitamin D From food or from exposure to sunlight SPF of 8 or above prevents the synthesis of vitamin D from sunlight What are the consequences of vitamin D deficiency in children What are they in adults 1 Rickets is a disease state associated with a clinical vitamin D deficiency in children Structural integrity of the bones is diminished leading to characteristic bowed legs and beaded ribs The occurrence of a clinical vitamin D deficiency in adults is called osteomalacia This disease process results in deformities and painful bone disease Osteoporosis which is manifested by decreased bone mineral density can result in loss of height and increased fractures Individuals who do not consume adequate amounts of vitamin D are at risk for bone fractures due to accompanying calcium loss What is the major idea behind fortification of food products with vitamin D in the United States Food products are fortified with vitamin D in the U S in order to provide a stable consistent source of the vitamin for the general population There are few natural food sources and not everyone can maintain adequate blood levels through skin synthesis alone Fortified food sources high in vitamin D include dairy food products Many people do not consume adequate amounts of this vitamin because they limit their dairy intakes due to either possible intolerance issues and or personal preferences Consumption of dairy products has declined in recent years due to these issues so the fortification process ensures that even with a more limited intake of these items vitamin D levels are consistent What fat soluble vitamin has the lowest risk of deficiency Vitamin E Why is vitamin K given to newborns at birth What happens if the newborn does not get the injection A vitamin K injection is recommended for all newborns in order to provide needed vitamin K until its intestinal production by bacteria begins Since the infant is born with a sterile gut there are no bacteria present to start this bodily process A one time injection is all that is required If the injection is not given then the newborn is at risk to develop a bleeding disorder resulting in hemorrhagic disease of the newborn What are two ways that people can obtain vitamin K 1 2 Diet Bacteria in GI tract Fill in the following chart Vitamin A Vitamin Main role Vision Protein synthesis cell differentiation reproduction and growth antioxidant Deficiency Infectious Diseases night blindness blindness Excess Bone defects Birth defects Helps to maintain blood In children rickets Toxicity Food sources Fortified milk margarines eggs betacarotene found in spinach and dark green vegetables deep orange fruits liver Vitamin D in 2 D Vitamin E levels of calcium and phosphorus Antioxidant In adultosteomalacia Primary deficiency rare Erythrocyte hemolysis Symptoms Loss of muscle coordination and reflexes Impaired vision and speech Nerve damage Erythrocyte hemolysis disease is called hypervitamino sis D Foods Fortified milk butter and margarine Egg yolks liver Rare Polyunsaturated plant oils such as margarine salad dressings and shortenings May augment the effects of anticlotting medication Leafy green vegetables Wheat germ Whole grains Liver and egg yolks Vitamin K Synthesis of blood clotting proteins Synthesis of bone proteins that regulate blood calcium Hemorrhaging Secondary deficiency may occur with use of antiobiotics Newborn infants receive a single dose of vitamin K at birth because of a sterile intestinal tract Uncommon High doses can decrease the effectiveness of anticlotting medications Nuts and seeds Bacterial synthesis in digestive tract Liver milk leafy green vegetables 3