Nutrition chs. 7, 8, 9

free radicals => oxidative stress => can accelerate the process of aging and increase the risk of:

- heart disease - cancer - diabetes - arthritis - macular degeneration - Parkinson's - Alzheimer's antioxidants help neutralize free radicals, limiting the damage that free radicals cause and helping to reduce the risk of many chronic diseases free radicals can also damage your eyes by contributing to age-related macular degeneration and cataracts

functions of vitamin E

1. antioxidant 2. anticoagulant (stops platelets from unnecessarily clumping together and creating a damaging clot in your bloodstream). 3. alters the stickiness of the cells that line your lymph and blood vessels. this decreases the ability of blood components to stick to these walls and clog these passageways. (*studies at the moment don't support the use of vitamin E supplements to protect against heart disease)

functions of vitamin A

1. cell division and differentiation - it affects cell division by prompting gene expression. as cells divide and cluster together, changes occur that cause them to become different from their initiating cells. this differentiation determines what they become in your body. ex. when immature skin cells differentiate into mature skin cells, vitamin A acts as a signal to turn on the genes to create the proteins needed to make healthy skin. - during the early stages of pregnancy, vitamin A signals cells to differentiate into tissues that form the baby's body. it plays a particularly important role in the development of the lungs, kidneys, heart, ears, and other organs 2) bone growth - it may regulate the cells involved in bone growth through gene expression - too much may negatively affect healthy bones 3) bone health - important for keeping your skin and the mucous membranes of your lungs, GI tract, and kidneys healthy and structurally sound. if these linings are weakened or damaged, bacteria and viruses can infiltrate your body and make you sick - also helps keep your skin healthy to prevent bacteria from entering your body - also works with your immune system to create WBCs that fight pathogens that enter your bloodstream

functions of vitamin K

1. essential for blood clotting (major function -- "klotting") blood clotting is a complex chain of events involving substances in the blood, many of which are proteins => clotting factors. vitamin K plays a role in synthesizing four of these clotting factors. without vitamin K, a simple cut on your finger would cause uncontrollable bleeding. 2. also, as a coenzyme, aids an enzyme that alters the bone protein osteocalcin, helping it to bind with calcium, leading to bones being strengthened - chronic inadequate amounts of K may be a factor in osteoporosis

functions of D

1. once in an active form, acts as a hormone and regulates 2 important bone minerals-- Ca and P. it stimulates the absorption of Ca and P in the GI tract, helping to keep the levels of the minerals within a healthy range in your blood. because of its role in regulating these minerals, D helps to build and maintain your bones. although P deficiency is very rare, dietary Ca deficiencies do occur, causing blood levels of Ca to drop. when this happens, D and parathyroid hormone cause Ca to leave your bones to maintain the necessary levels in your blood. D then signals your kidneys to decrease the amount of Ca excreted in the urine. all of these actions help to regulate the amount of Ca in your blood may prevent some cancers (breast, colorectal, prostate) and other conditions (like diabetes, heart disease, high BP, and autoimmune disorders, like multiple sclerosis) important to a healthy immune system

how many vitamins are there?

13

how many different forms of naturally occurring vitamin E are there?

8 alpha-tocopherol is the most active in your body. the synthetic form of vitamin E found in dietary supplements is only half as active as the natural form

how many water-soluble vitamins are there? and how many belong to the vitamin B complex?

9 water-soluble 8 belong to the vitamin B complex

where are vitamins A, K, E, and D stored?

A-- largely in the liver K and E -- lesser extent in the liver D-- mainly in the fat and muscle tissues because they're stored in the body, large quantities of some of the fat-soluble vitamins, especially A and D, can build up to the point of toxicity, causing harmful symptoms and conditions

cataract

disorder in which the lens of the eye becomes cloudy, resulting in blurred vision more than half of all Americans have experienced cataracts by the time they reach 8-, and many undergo surgery to remove them the NIH recommends consuming antioxidant-rich fruits and vegetables, like leafy green vegetables and fruit, for the health of your eyes

T/F fortified foods are a safe way to get your daily vitamins

false they're not always a safe way to meet your vitamins need (ahem, energy drinks)

__-___ vitamins are absorbed at the beginning of your small intestine

fat-soluble

what kind of vitamins can be toxic in high doses?

fat-soluble

which vitamins are fat-soluble, and which are water-soluble?

fat-soluble: A, D, E, K water-soluble: Bs, C

what does the macula allow you to see?

fine details and things that's straight in front of you

where do free radicals originate from? and what do they do?

from the process of oxidation-- these damage cell structure, cell proteins, and even DNA they steal electrons from other molecules in order to stabilize themselves. the robbed molecule then itself becomes a free radical and looks for another molecule to attack. if this chain reaction isn't stopped, it can significantly damage cells they are the normal by-products of your body's metabolic reactions, which convert energy from food. they can also result from exposure to chemicals in the environment (like cigarette smoke and air pollution) and from the damaging effects of the sun's UV rays on unprotected skin

too much vitamin E...

there isn't any known risk of consuming too much from natural food sources. however, overconsumption of the synthetic form that's found in supplements and/or fortified foods could pose risks. because vitamin E can act as an anticoagulant and interfere with blood clotting, excess amounts in your body increase the risk of hemorrhage. this applies only to healthy individuals consuming adequate amounts of vitamin K. (vitamin K also plays a role in blood clotting. a deficiency of K can exacerbate E's anticoagulant effects). individuals taking anticoagulant medication and vitamin E supplements should be monitored by their physician to avoid the serious situation in which the blood can't clot quickly enough to stop the bleeding from a wound)

folate's role in cancer

inadequate amounts of folate in the body can disrupt the cell's DNA, potentially triggering cancer development. while research has shown that an adequate intake of folate may help reduce the risk of certain cancers, specifically colorectal cancer, some studies suggest that folic acid supplements may have no effect or actually increase the risk of prostate cancer.

deficiency of __ causes beriberi

thiamin

too much/too little riboflavin

too much => no UL set actually too little: if you don't consume enough of this B vitamin, the cells in the tissues that line your throat, mouth, tongue, and lips will be the 1st to signal a deficiency. your throat would be sore, the inside of your mouth would swell, your tongue would be inflamed and look purplish red, and your lips would be dry, cracked and scaly. deficiencies are rarely seen in healthy individuals who eat a balanced diet.

too much/too little vitamin D

too much: - loss of appetite - weight loss - irregular heart beat - increased urination accumulation can reach toxic levels, causing hypervitaminosis D. This condition causes over absorption of Ca from the intestines as well as calcium loss from bones. when both of these symptoms occur, blood Ca levels can become dangerously high a chronically high amount of Ca in the blood (hypercalcemia) can cause damaging Ca deposits in the tissues of your kidneys, lungs, blood vessels, and heart it is highly unlikely that you'll get hypervitaminosis D from foods, even fortified foods. the only exception is fish oils, like cod-liver oil, which provides 1,360 IU of vitamin D per tablespoon. a more likely culprit behind hypervitaminosis D is the overuse of D supplements.

vitamin toxicity (hypervitaminosis)

very rare-- the condition results from ingesting more of the vitamin than the body needs, to the point where tissues become saturated the excess vitamin can damage cells, sometimes permanently vitamin toxicity doesn't occur by eating a normal balanced diet. it can result when individuals consume megadose levels of vitamin supplements, usually in the mistaken belief that more is better.

which vitamins can be synthesized in your body or by microbes in the GI tract?

vitamins D and K, niacin, and biotin

preformed vitamins

vitamins that's found in active form in foods-- don't undergo conversion in the body

air (oxygen) can destroy what?

water-soluble vitamins and A, E, and K

too little vitamin E

individuals who can't absorb fat properly may fall short of their E needs. though rare, a chronic deficiency can cause nerve problems, muscle weakness, and uncontrolled movement of body parts. because vitamin E is an antioxidant and is found in the membranes of RBCs, a deficiency can also increase the susceptibility of cell membranes to damage by free radicals.

polyneuritis

inflammation of the peripheral nerves (similar disease to beriberi, which is a human one-- this one was noticed in birds)

where are water-soluble vitamins absorbed? where is vitamin B12 absorbed?

most are absorbed in the upper portion of your small intestine. vitamin B12 is absorbed in the lower part of your small intestine

too much/too little vitamin K

no adverse effects known for eating too much individuals taking anticoagulant meds like warfarin/coumadin need to maintain a consistent intake of K. this medication decreases the activity of K and prolongs the time it takes for blood to clot. if these individuals suddenly increase K in their diets, the vitamin can override the effect of the drug, enabling the blood to clot too fast. in contrast, a sudden decline in K can enhance the effectiveness of the drug a vitamin K deficiency severe enough to affect blood clotting is very rare in healthy individuals. people with illnesses affecting absorption of fat in the GI tract, which is necessary to absorb fat-soluble K, may be at risk of not meeting their K needs.

what does vitamin C do in the body?

plays important roles in the immune system and in tissue health, in addition to its antioxidant function

vitamin E's claim to fame

powerful antioxidant extremely important in protecting cell membranes and preventing oxidation of LDLs because many phospholipids contain unsaturated fatty acids, they are vulnerable to the damaging effects of radicals. as an antioxidant, E neutralizes free radicals before they can harm cell membranes when LDLs are oxidized, they contribute to the buildup of artery-clogging plaque. thus, antioxidants like E can help prevent atherosclerosis

Wernicke-Korsakoff syndrome

progressively damaging brain disorder that can cause - mental confusion - memory loss - loss of muscle coordination - leg tremors - abnormal eye movements - hallucinations although some of these symptoms can be reversed after the person is medically treated w thiamin, some of the memory loss may be permanent.

too little folate

research suggests that people w low levels of folate in their blood might be at increased risk for depression and that folate supplements could increase the effectiveness of antidepressant meds.

vitamin D

whether from food or sunlight, D enters body in an inactive form. the UV rays of the sun convert a cholesterol-containing compound in your skin to provitamin D, which is then converted to an inactive form of D in your blood. The D in your foods is also in this active form. this inactive form travels in your blood to your liver, where it's changed into a circulating form of D and is released back into your blood. once in the kidneys, it's converted to an active form of D.

age-related macular degeneration (AMD)

results from damage to the macula, a tiny area of the retina that's needed for central vision (the ability to see things that're directly in front of you) - can make activities like reading, driving, and watching TV hard - a common eye condition among those who are 50 yrs of age and older - a leading cause of vision loss among older individuals - supplements containing large amounts of antioxidants (vitamin C, vitamin E, lutein, and zeaxanthin) with the minerals Zn and Cu are effective in reducing the risk for AMD and the extent of vision loss

functions of riboflavin

your body needs riboflavin to turn the carbs, proteins, and fats that you eat into energy and to keep the cells in your body healthy.

what are provitamins?

substances found in foods that can be converted into an active vitamin form once they're absorbed

osteomalacia

the adult equivalent of rickets. can cause muscle and bone weakness and pain. the bone's can't mineralize properly because there isn't enough Ca and P available in the blood. although there may be adequate amounts of these minerals in the diet, the deficiency of vitamin D hampers their absorption (so, vitamin D needed for the absorption of Ca and P) vitamin D deficiency and its subsequent effect on decreased Ca absorption can also lead to osteoporosis. adequate dietary intake of both Ca and vitamin D is necessary to maximize bone density.

what are your daily vitamin D needs based on?

the amount you would need to eat in foods and not on the synthesis of D in your skin from sunlight

too little vitamin A...

a chronic deficiency can lead to an inability to regenerate rhodopsin, causing night blindness. such individuals have difficulty seeing at dusk because they can't adjust from daylight to dark and may not be able to drive a car during this time of day. if diagnosed early, night blindness can be reversed by taking vitamin A a prolonged deficiency can lead to dryness and permanent damage to the cornea (xerophthalmia). vitamin A deficiency is the #1 cause of preventable blindness in children. a deficiency is also associated with stunting of bones

diets high in what kinds of things are associated with a lower incidence of some diseases, including cancer?

antioxidant-rich fruits, vegetables, and whole grains and phytochemicals (which have many beneficial functions in the body, including acting as antioxidants)

what happens with rhodopsin and vitamin A when there is incoming light?

as rhodopsin absorbs incoming light, the shape of vitamin A is altered, and it detaches from its protein. this causes a cascade of events that transmits visual messages through your optic nerve to your brain. this change in rhodopsin=> BLEACHING. although the breakdown of iodopsin is similar, rhodopsin is more sensitive to dim light than iodopsin and is more likely to become bleached. after bleaching, the vitamin A returns to its original shape and becomes part of the protein again, regenerating the eye's light-absorbing capabilities. this regeneration process can take a few moments. (after bleaching, some vitamin A is lost)

too much/too little niacin/B3

as with most water-soluble vitamins, there isn't any known danger from consuming too much niacin from foods like meat and enriched grains. however, over consuming niacin by taking supplements or eating too many overly fortified foods can cause flushing, a reddish coloring of the face, arms, and chest. too much niacin consumption can also cause N/V, be toxic to your liver, and raise BGLs UL for adults: 35 mg to prevent flushing, the first side effect to be observed when too much niacin is consumed. this upper limit applies only to healthy individuals. it may be too high for those w certain medical conditions, like diabetes and liver disease. too little niacin in the diet can cause pellagra. symptoms: dermatitis (inflammation/irritation of the skin), dementia, and diarrhea (and death) -- the 4 Ds

where are the fat-soluble vitamins absorbed?

at the beginning of your small intestine. they're packaged w fatty acids and bile in micelles, small transport carriers, that shuttle them close to the intestinal wall. once there, the fat-soluble vitamins travel through the cells in the intestinal wall and are packaged with fat and other lipids in chylomicrons (lipoprotein carrier). the vitamins then travel through your lymph system before they enter your bloodstream. So... micelle--> chylomicron --> lymph

rickets

bones of children w rickets aren't adequately mineralized with Ca and P, and this causes them to weaken. because of their soft bones, these kids develop bowed legs, as they are unable to hold up their own body weight when they're standing upright. breastmilk is low in D, and cases of rickets in the US are most frequently seen in breastfed black infants and kids.

how can water-soluble vitamins be destroyed?

by exposure to AIR, WATER, or HEAT vegetables and fruits begin to lose their vitamins almost immediately after being harvested, and some preparation and storage methods can accelerate vitamin loss. although the fat-soluble vitamins tend to be more stable than water-soluble vitamins, some food preparation techniques can cause the loss of these vitamins too.

which mineral does Vitamin K work with?

calcium

what common role do B vitamins share?

coenzyme (helping numerous enzymes produce reactions in your cells) although vitamins don't provide calories and thus aren't sources of energy, you need many of the Bs to use the 3 energy-yielding nutrients (carbs, proteins, fat) Bs needed to UTILIZE the energy-carrying units

how is the daily need of vitamin K determined?

currently, it's not known how much of K made from bacteria in your GI tract contributes to meeting daily needs. because of this, it's hard to pinpoint the exact amount you need to consume daily in your foods. thus, the recommendation for dietary K is based on the current amount that's consumed on average by healthy Americans

T/F Too much Vitamin E can interfere with blood clotting

true

T/F Vitamin K keeps your bones healthy

true Vitamin K helps a protein in your bones bind with the bone-strengthening mineral calcium.

T/F folate reduces the risk of certain birth defects

true folate can lower the risk of some birth defects during pregnancy

T/F All water-soluble vitamins are typically not stored in your body for long periods of time.

true, except for vitamin B12

bioavailability of vitamins

varies according to several factors, including 1) the amount of the vitamin in the food 2) whether the food is cooked, raw, or refined 3) how efficiently the food is digested and absorbed 4) the individual's nutritional status 5) whether the vitamin is natural or synthetic not all of the vitamins consumed in food care available to be used in the body. they aren't 100% bioavailable. in general, if the the body needs more vitamins, a greater % will be absorbed (e.g. in the case of a young child or pregnant woman) the bioavailability of fat-soluble vitamins is usually less than that of water-soluble vitamins because fat-soluble vitamins require bile salts and the formation of a micelle to be absorbed. vitamins in plant foods are typically less bioavailable than those in animal foods because plant fiber can trap vitamins.

too much vitamin A....

consuming more than 15000 micrograms of preformed vitamin A at one time or over a short period of time can lead to N/V, headaches, dizziness, and blurred vision chronic daily consumption of more than 30,000 micrograms of vitamin A (more than 300 XS the amount that adults need daily) can lead to hypervitaminosis A, an extremely serious condition in which the liver accumulates toxic levels of vitamin A. it can lead to deterioration and scarring of the liver and even death high intake of preformed vitamin A during pregnancy, particularly in the 1st trimester, can cause birth defects in the face and skull and lungs. all women of childbearing age who are using retinoids for acne or other skin conditions should take the proper steps to avoid becoming pregnant. although vitamin A is needed for bone health, some research suggests that consuming too much may lead to osteoporosis, which in turn increases the risk of fractures. the upper limit applies ONLY to preformed vitamin A from foods, fortified foods, and supplements. provitamin A carotenoids in foods are not toxic and don't pose serious health problems. your body has a built-in safeguard to prevent provitamin A carotenoids from contributing to vitamin A toxicity, birth defects, or bone damage. if you consume more carotenoids than you need to meet your vitamin A needs, your body will decrease their conversion to retinol. extra amounts of carotenoids are stored in your liver and in the fat under your skin.

what role does folate play in pregnancy?

extremely important role-- especially in the 1st few weeks after conception, often before the mom knows she's pregnant - needed to create new cells so that the embryo can grow and develop a deficiency during pregnancy can result in birth defects => neural tube defects. the neural tube, which differentiates into the fetal spine, brain, and skull, is formed during the 1st 12 weeks of gestation. if it doesn't develop properly, 2 common birth defects-- anencephaly and spina bifida (baby's spinal cord and vertebrae aren't properly developed, causing physical disabilities, like the inability to walk)-- can occur folic acid could possibly reduce the risk of these birth defects by 50-70% if consumed at least the month prior to conception and during the early part of pregnancy according to some research, consuming adequate quantities of folic acid before and during pregnancy may also decrease the child's risk of developing autism

too much folate

no danger in consuming excessive amounts of naturally occurring folate in foods. consuming too much folic acid, either through supplements or fortified foods, can be harmful for individuals who are deficient in B12. A B12 deficiency can cause anemia and more dangerous, crippling and irreversible nerve damage. too much folate in the diet masks the symptoms of B12-deficiency anemia and may even exacerbate the anemia. though the folate can correct anemia, the nerve damage due to the vitamin B12 deficiency persists. this delays a proper diagnosis and corrective therapy w B12. by the time the person is given B12, irreversible nerve damage may have occurred. while low folate intake may be associated w increased cancer risk, studies suggest that folate consumption double the DRI or even higher may also increase the risk of some cancers. a folate deficiency can result in abnormally large and immature blood cells (megaloblasts). these megaloblasts develop into abnormally large RBCs/macrocytes that have a diminished oxygen-carrying capacity. eventually, microcytic anemia causes a person to feel tired, weak, and irritable and to experience SOB. because folate acts w B12 to produce healthy RBCs, a deficiency of either vitamin can lead to microcytic anemia.

too much/too little thiamin (B1)

no known toxicity symptoms from consuming too much thiamin from food or supplements, so no UL has been set deficiency=> beriberi. 2 types 1. Wet beriberi - affects the cardiovascular system, so symptoms often include a rapid heart beat, SOB, and edema in a person's calves and feet 2. Dry beriberi - affects the nervous system, so symptoms may include difficulty in walking, tingling, and loss of feeling in the hands and feet, confusion, and problems with coordination the populations of poor countries with an inadequate food supply rely heavily on refined grains that aren't enriched.(recall that enriched grains have the B vitamins-- thiamin, riboflavin, niacin, and folic acid-- plus Fe added to them). these people are more susceptible to a thiamin deficiency and the side effects of beriberi. in america, people w an alcohol use disorder tend to have a poor diet that's probably deficient in thiamin. alcohol consumption also interferes with the absorption of the small amounts of thiamin that may be in the diet, accelerating its loss from the body. people w alcohol use disorder may find themselves battling a thiamin deficiency that can cause beriberi and lead to an advanced form of thiamin deficiency called Wernicke-Korsakoff syndrome

what are vitamins?

non-energy-providing organic essential nutrients that your body needs in small amounts to grow, reproduce, and maintain good health

too much/too little B6

too much: while UL is set at 100 mg, taking vitamin B6 in supplement form can be harmful. - over the years B6 has been touted to aid the symptoms of premenstrual syndrome (PMS), which include moodiness, irritability, bloating, and anxiety. however, more research is needed to determine if vitamin B6 supplements would help reduce PMS in women. chronically taking large amounts of B6 through supplements has been associated w a variety of ill effects, including nerve damage, losing control of bodily movements, and GI issues like nausea and heartburn. typically, these symptoms subside once supplement consumption stops. too little: the telltale signs of B6 deficiency= sore tongue, skin inflammation, depression, confusion, and possibly anemia individuals w an alcohol use disorder are at increased risk of deficiency because alcohol causes the body to lose B6. in addition, these individuals are more likely to consume an unbalanced diet w little variety.