Final Review and Assessment of Profile and Nutritional Health – FSM 159 Nutrition - 30 points After you have completed your IProfile analysis and your personal iProfile questions - you must now review
Chapter 7 Vitamins A Vitamin Primer • Vitamins are organic compounds that are essential in small amounts. • Promote and regulated body processes necessary for growth, reproduction, and maintenance of health. • When a vitamin is lacking, deficiency symptoms occur. • When the vitamin is restored to the diet, deficiency symptoms disappear. • Water -soluble vitamins: o B vitamins and vitamin C • Fat -soluble vitamins: o Vitamins A, D, E, and K. Vitamins in Our F ood • All foods contain some vitamins. • All the food gr oups contain foods that are good sources of a variety of vitamins. • The amount present in food depends on: o The amount that is naturally present. o What is added to it. o How the food is processed, prepared, and stored. • Even though vitamins are in all food groups, the amounts vary. Example: grains, fruits, and vegetables lack B12; grains, dairy, and protein foods are low in Vitamin C. • Fortification adds nutrients to foods. • DEBATE: Discretionary Fortification: Is it Beneficial? o Do we need these extra nutrients? Can they pose a risk of toxicity if eaten in large quantities? o Fortification began as a way to address nutrient deficiencies. ▪ Government mandated fortification: B vitamins, vitamin A and D, and iodine. ▪ Indiscriminate fortification: e.g. breakfast cereals. ▪ Increasing product sales. • Vitamins in foods can be damaged by exposure to light or oxygen. o Washed away during preparation. o And destroyed during cooking. Vitamin Bioavailability o Bioavailability: the extent to which the body can absorb and use a nutrient. o 40 -90% of the vitamins in food are absorbed. o Absorption is affected by the composition of the diet and conditions in the digestive tract. o Provitamin or vitamin pr ecursor: a compound that can be converted into the active form of a vitamin in the body. Vitamin Functions • Antioxidants : substances that help protect cells from oxidative damage. o Vitamin C, vitamin E, and provitamin A. • Healthy immune function. o Vitamins A, B6, C and D, and folate. • Normal growth and development. o Vitamin A and D. • Needed to produce ATP from carbohydrate, fat, and protein. o B vitamins thiamin, riboflavin, niacin, biotin, pantothenic acid and vitamin B6. • Important for protein and amino acid metabolism. o Folate, vitamin B6, and vitamin B12. • Keep blood healthy. o Folate, vitamin B6, vitamin B12, and vitamin K. • Needed for bone health. o Vitamins A, D, K, and C. • Coenzymes : organic non -protein substances that bind to enzymes to promote their activity. Meeting Vitamin Needs • In developing countries: vitamin deficiencies remain a major public health concern. • In develop ed countries: eliminat ion of most vitamin -deficiency diseases. o Concern for meeting needs of high -risk groups – pregnant women and children. o Determining consequences of marginal deficiencies. o Evaluating the risk of consuming toxic amounts of certain vitamins. • RDAs and AI of the DRIs recommend amounts that provide enough of each of the vitamins to prevent a deficiency and promote health. • Established ULs to avoid risk of toxicity. • Food labels can help identify packaged foods that are good sources of vitamins. o Required to list vitamin D. o General Guide: ▪ If the %Daily Value is 5% or less, the food is a poor source of that nutr ient. ▪ If the %Daily Value is 10 -19%, the food is a good source of that nutrient. ▪ If the %Daily Value is 20% or more, the food is an excellent source of that nutrient. Vitamin and Energy Metabolism Thiamin • Vitamin B1 is water soluble . • Deficiency: Dry Beriberi: causes we akness, nerve degeneration. Wet Beriberi: causes heart changes. o Common where polished white rice is a staple of the diet. o Wernicke -Korsakoff syndrome: a thiamin deficiency occurring most often in alcoholics. ▪ Confusion, los s of coordination , vision changes, hallucinations, and eventually coma and death . • Co -enzyme needed for the breakdown of glucose to provide energy. o Important for nerve function. • Needed for the synthesis of neurotransmitters: chemical substances produced by a nerve cell that can stimulate or inhibit another cell. • Needed for the metabolism of other sugars and certain amino acids. • Needed for the synthesis of ribo se and deo xyribose , part of the structure of RNA and DNA respectively . • Food Sources: bran layer of rice and whole grains, o Added to enriched grains. o Abundant in pork , legumes, and seeds. • No UL because no toxicity has been reported when an excess of this vit amin is consumed in food or supplements. Riboflavin • Water soluble vitamin. • Excess consumption turns the urine bright fluorescent yellow; it is harmless. • No adverse effects from high doses from either food or supplements have been reported. • Forms two active coenzymes that act as electron carriers. • Function in the reactions needed to produce ATP from carbohydrate, fat, and protein. • Involved directly or indirectly in converting a number of other vitamins, including folate, niacin, vitamin B6 and vitamin K, into their active forms. • Foo d sources: dairy products , red meat, poultry, fish, whole grains, and enriched breads and cereals. o Vegetable sources: asparagus, broccoli, mushrooms, and leafy green vegetables. • Deficiency symptoms: injuries heal poor ly becau se new cells cannot grow. o Tissues that grow rapidly are the first affected: skin and the linings of the eyes, mouth and tongue; cracking of the lips and corners of mouth . o Increased sensitivity to light; burning, tearing, and itching of the eyes. o Flaking of the skin around the nose, eyebrows and earlobes. o A deficiency usually occurs in conjunction with deficiencies of other B vitamins. Niacin • Pellagra: disease resulting from niacin deficiency, which causes dermatitis, diarrhea, dementia, and, if not treated, death. • Water soluble vitamin. • Coenzymes essential for gluc ose metabolism and th e synthesi s of fatty acids and cholesterol. • Food sources: meat, fish, peanuts, and whole and enriched grains are the best sources. o Other sources: legumes and wheat bran. • Can be synthesized from tryptophan – if diet is adequate. • RDA expressed as niacin equivalents (NEs). o One NE is equal to 1 mg niacin or 60 mg tryptophan. • Toxicity possible from supplements. o Excess niacin from supplement s can cause flushing of the skin , a tingling sensation in the hands and feet, a red skin rash, nausea, vomiting, diarrhea, high blood sugar levels, abnormalities of liver function, and blurred vision. o No evidence of adverse effects from food but supplements can be toxic . o UL for adults is 35 mg. Biotin • Coenzyme that functions in energy production and glucose synthesis. o Also important in the metabolism of fatty acids and amino acids. • Water soluble vitamin. • Good food sources: cooked eggs, liver, yogurt, and nuts. o Fruit and meat are poor so urces. o Bacteria in the GI tract can synthesize. • AI 30 µg/day for adults . • Deficiency is uncommon. o Deficiency has been observed in people with malabsorption and those taking certain medications for a long period. o Eating raw eggs can cause a deficiency. o Symptoms: nausea, thinning hair, loss of hair color, a red skin rash, depression, lethargy, hallucinati ons, and tingling of the extremi ties. • No UL set . Pantothenic Acid • Water soluble vitamin. • Functions: part of coenzyme A (CoA) needed for the breakdown of carbohydrates, fatty acids, and amino acids. o Synthesis of neurotransmitters, steroid hormones, and hemoglobin. o Needed to form a molecule that is essential for the synthesis of cholesterol and fatty acids. • Sources: widely distributed in fo ods. o Good sources: meat, eggs, whole grains, legumes • Deficiency: rare. • AI is 5 mg/day for adults . • Nontoxic. No established UL. Choline • Not currently classified as a vitamin but is considered an essential nutrient. • Water -soluble substance. • Included in supplements called “vitamin B complex.” • Needed to synthesize a number of important molecules in the body, including the neurotransmitter acetylcholine; the structure and function of cell membranes, lipid transport, and homocysteine metabolism. o Can be synthesized by the body. • Deficiency: during pregnancy can interfere with brain development of fetus; in adult it causes fatty liver and muscle damage. • AIs: 550 mg/day for men; 425 mg/day for women. o UL: 3.5 g/day for adults o Deficiency is unlikely in healthy humans in the U.S. • Food sources: large amounts in egg yolks, liver, meat, fish, nuts, and wheat germ. • Excess choline intake from food and supplements: causes a fishy body odor, sweating, reduced growth rate, low blood pressure, and liver damage. Vitamins and Healthy Blood ▪ Vitamins needed to support the synthesis of red blood cells and blood -clotting proteins. Vitamin B6 • Functions: a water soluble vitamin important for amino acid and protein metabolism. o Needed to synthesize nonessential amino acids, make neurotransmitters, synthesize hemoglobin, convert tryptophan into niacin, and break down of glucose and amino acids, and synthesis of lipids . • Three forms: pyridoxal, pyridoxine, and pyridoxamine. o Can be c onverted into the active coenzyme pyridoxal phosphate. ▪ Needed for the activity of more than 100 enzymes involved in the metabolism of carbohydrate, fat, and protein. • Deficiency: leads to poor growth, skin lesions, decreased immune function, anemia, and ne urological symptoms. o Can be hastened by a diet that is low in vitamin B6 but high in protein. o If vitamin B status is low, homocysteine levels rise. ▪ Elevated homocysteine levels have been shown to increase risk of heart disease. • Food sources: o Animal source s: chicken, fish, pork, and organ meats. o Good plant sources: whole -wheat products, brown rice, soybeans, sunflower seeds, and some fruits and vegetables. ▪ Bananas, broccoli and spinach. • RDA for adults is 1.3 mg/day. • Toxicity: no adverse effects from high in take in foods. o Large doses from supplements can cause severe nerve impairment. o UL 100 mg/day from food and supplements for adults . o Some evidence that excess vitamin B will relieve symptoms of carpal tunnel syndrome or premenstrual syndrome ; will improve immune function but only in people deficient in Vitamin B6 . Folate (Folic Acid) • Water soluble vitamin. • Important during embryonic develo pment. o Low folate intake during pregnancy increases the risk of neural tube defects:abnormalities in the bra in or spinal cord that result from errors that occur during prenatal development. • Folic acid: an easily absorbed form of the vitamin folate that is used in dietary supplements and fortified foods. • RDA for folate: expressed in dietary folate equivalents (DFEs) o This measure corrects for differences in the bioavailability of different forms of folate. o One DFE is equal to 1 µg of food folate, 0.6 µg of synthetic folic acid from fortified foods or supplements consumed with food, or 0.5 µg of synthetic folic acid consumed on an empty stomach. • Folate coenzymes are needed for the synthesis of DNA and the metabolism of some amino acids. o Important in tis sues in which cells are dividing rapidly: intestines, skin, embryonic and fetal tissues, and bone marrow. • Deficiency symptoms: macrocytic anemia or megaloblastic anemia. o Other symptoms: poor growth, problems with nerve development and function, diarrhea, a nd inflammation of the tongue. o Low folate status may increase the risk of developing heart disease . o Folate and vitamin B12 are both needed to prevent homocysteine levels from rising. o Populations most at risk of folate deficiency: pregnant women, premature infants, the elderly, alcoholics, and tobacco smokers. • Food sources: Excellent source : leafy greens, such as spinach, asparagus, oranges, legumes, and liver. o Fair sources: whole grains, corn, snap beans, mustard greens, and broccoli; some nuts. o Small amounts: meats, cheese, milk, fruits, and other vegetables. • RDA 400 µg/day for adult men and women . Vitamin B12 • Also known as cobalamin is water soluble . • Pernicious anemia: macrocytic anemia resulting from vitamin B12 deficiency that occurs when dietary v itamin B12 cannot be absorbed due to a lack of intrinsic factor. o Intrinsic factor: protein produced in the stomach that is needed for the absorption of adequate amounts of vitamin B12. o Atrophic gastritis: an inflammation of the stomach lining that results in reduced secretion of stomach acid, microbial overgrowth, and, in severe cases, a reduction in the production of intrinsic factor. • Functions: necessary for the production of ATP from certain fatty acids. o Needed to convert homocysteine to methionine o Need to maintain the myelin coating on nerves. o When vitamin B12 is deficient, homocysteine levels rise, and folate cannot be converted into its active form. The lack of folate causes macrocytic anemia. ▪ Lack of vitamin B12 also leads to degeneration of the myeli n that coa ts the nerves in the spinal cord and brain. ▪ Symptoms: numbness and tingling, abnormalities in gait, memory loss, and disorientation. If not treated, leads to paralysis and death. • Food sources: found only in animal products. o Supplements or fortifi ed foods are needed to provide this nutrient for vegans. o RDA 2.4 µg/day for adult men and women. ▪ UL: Insufficient data to establish. Vitamin K • A fat soluble vitamin needed for blood clotting. • The K in vitamin K comes from the Danish word for coagulation, koagulation, which means “blood clotting.” • Deficiency: abnormal blood coagulation. o With vitamin K deficiency, blood clotting factor, including prothrombin, are not made correctly, and the blood will not clot. What a Scientist Sees: Anticoagulants Takes Lives and Save Them • Warfarin is an anticoagulant, prevents blood from clotting. • Used as a rat poison. • Used as an anticoagulant to prevent blood clot formation in humans. o Known by brand name Coumadin. Meeting vitamin K needs • Needed for the synthesis of several proteins involved in bone formation and breakdown. Inhibit blood vessel calcification. Regulate cell growth. • Adequate vitamin K may be important to decrease risk of fractures due to osteoporosis, and reduce risk of atherosclerosis and cancer. • The body uses vitamin K rapidly; a constant supply is needed. • Food sources: leafy green vegetables and some vegetable oils. • Nonfood source: synthesis by bacteria in the intestine. • Deficiency: can be precipitated by poor diet, Crohn’s disease, or long -term antibiotic use, which kills the bacteria in the GI tract. o Newborns at risk: no bacteria in the GI tract at birth; little vitamin K is transferred from the mother before birth; breast milk is a poor s ource. ▪ Infants are commonly given a vitamin K injection within six hours of birth. Antioxidant Vitamins • Antioxidant: substance that decreases the adverse effects of reactive molecules on normal physiological function. • Oxidative stress: imbalance between r eactive oxygen molecules and antioxidant defenses that result in damage. • Free radical: type of highly reactive molecules that cause oxidative damage Vitamin C • It i s water soluble, and also known as ascorbic acid. • Functions: synthesis and maintenance of co llagen o Needed in reactions that synthesize neurotransmitters, hormones, bile acids, and carnitine. o An antioxidant that acts in the blood and other body fluids. ▪ Regenerates the active antioxidant form of vitamin E. ▪ Enhances iron absorption in the small intestine. • Deficiency: Scurvy: characterized by bleeding gums, tooth loss, joint pain, bleeding into the skin and mucous membranes, and fatigue. • Food sources: citrus fruits, strawberries, kiwis, and cantaloupe. o Vegetables: cabbage family, dark green leafy vegetables, green and red peppers, okra, tomatoes and potatoes. o Poor sources: meat, fish, poultry, eggs, dairy products, and grains. • Is destroyed by oxygen, light, and heat. o Readily lost in cooking. • RDA: 90 mg/day for men; 75 mg/day for women. o Cigarette sm oking increases requirement by an extra 35 mg/day (1/2 cup broccoli) . o UL: 2000 mg/day from food and supplements. • Supplements: one -third of the population takes in hopes of preventing the common cold. o Does not prevent colds or reduce the severity of symptoms; however it may help reduce the duration. o Insufficient data to support claims of reducing the risk of cancer or cardiovascular disease. o Excessive supplementation: diarrhea, nausea, abdominal cramps, and increased risk of kidney stone formation. ▪ In individuals unable to regulate iron absorption, excess vitamin C can increase absorption, allowing iron to reach toxic levels. ▪ In individuals with sickle cell anemia, excess vitamin C can worsen symptoms. ▪ Doses greater than 3 g/day may interfere with drug s prescribed to slow blood clotting. ▪ In chewable form, large doses of vitamin C can dissolve tooth enamel. Vitamin E • An antioxidant that protects lipids through -out the body by neutralizing reactive oxygen compounds before they can cause damage. • May help reduce risk of heart disease, and other diseases. • Protects membranes in red blood cells, white blood cells, nerve cells, and lung cells as well as lipids in lipoproteins . • Role in modulating immune response, reducing inflammation, allowing cells to com municate, regulation of genes, and inhibiting an early step in blood clot formation. • Fat soluble vitamin. Vitamin E deficiency • Hemolytic anemia: vitamin E deficiency where red blood cells may rupture; most common in premature infants. • Rare in adults. o Occu rs only when other health problems interfere with the absorption of fat. • The antioxidant role of vitamin E suggests that it may help reduce the risk of heart disease, and a variety of other chronic diseases associated with oxidative damage. • Vitamin E has a nti -inflammatory properties . • Supplementation has not been found to benefic ial in preventing heart disease. Meeting vitamin E needs • Food sources: nuts, seeds, and plant oils. o Fortified products such as breakfast cereals. • Vitamin E is sensitive to destruction by oxygen, metals, light, and heat. o When oil is heated repeatedly, most of the vitamin E is lost. • Tocopherol: the chemical name for vitamin E. o Several forms occur naturally in foods. o Only alpha -tocopherol (α -tocopherol) is used by the body. o RDA is expressed as mg α -tocopherol. o Synthetic α -tocopherol is used in supplements and fortified foods. ▪ Provides only half the vitamin E activity of the natural form. • No adverse effects from consuming large amount naturally present in foods. • The amou nt typically found in supplements is safe for most people. o Large doses can interfere with blood clotting. o Should not be used by individuals on blood -thinning medications o UL 1000 mg/d Vitamins in Gene Expression • Vitamin A and D have functions that depend o n their ability to regulate gene expression o Gene Expression: the events of protein synthesis in which the information coded in a gene is used to synthesize protein or a molecule of RNA • Cell differentiation o Immature cells change in structure and function to become specialized by changing gene expression (turning genes on and off) o Vitamin A helps ensure healthy eyes o Vitamin D promotes strong bones Vitamin A • It is a fat soluble vitamin. • Beta -carotene (β -carotene): a provitamin that can be converted into vitamin A in the body. Vitamin A in the diet • Retinoids: the chemical forms of preformed vitamin A: retinol, retinal, and retinoic acid. • Carotenoids: natural pigments synthesized by plants and many microorganisms . o They give yellow and orange fruits a nd vegetables their color. • Beta -carotene: most potent vitamin A precursor. o Alpha -carotene (α -carotene) and beta -cryptoxanthin (β -cryptoxanthin) are also provitamin A carotenoids. ▪ Not converted into retinoids as efficient as β -carotene. • Food sources: o Retino id sources: animal products such as liver, fish, eggs and dairy products. o Retinol sources: fruits and vegetables like carrot, broccoli, and cantaloupe. ▪ Not absorbed as well as retinoids. o Retinol activity equivalent (RAE) is used to express the amount of usable vitamin A in foods. ▪ 1 RAE is the amount of retinol, β -carotene, α -carotene, or β - cryptoxanthin that provides vitamin A activity equal to 1 µg of retinol. o Absorption is impaired when dietary fat intake is low. o Protein and zinc are important in preven ting vitamin A deficiency. Vitamin A functions and deficiency • Needed for vision and eye health. • Needed for normal cell differentiation: the process where immature cells change in structure and function to become specialized. • Retinal is part of rhodopsin, a visual pigment in the eye. o Night blindness: delay in the regeneration of rhodopsin. ▪ First sign of vitamin A deficiency. ▪ Easily reversible. • Necessary for the maintenance of epithelial tissue. o Skin, the linings of the eyes, intestines, lungs, vagina, and b ladder. o Eye is particularly susceptible. o Xerophthalmia: spectrum of eye conditions resulting from vitamin A deficiency that may lead to permanent blindness. • Needed for normal reproduction, growth, and immune function. Vitamin A toxicity • Preformed vitamin A is toxic in large doses. o Symptoms: nausea, vomiting, headache, dizziness, blurred vision, and lack of muscle coordination. ▪ Example: polar bear liver. • Excess vitamin A in pregnant women may contribute to birth defects. o Derivatives of vitamin A tha t used to treat acne (Retin A and Accutane) should never be used by pregnant women. • High intakes have been found to cause liver damage. • UL: 2800 µg/day of preformed vitamin A for 14 -18 year olds; 3000 µg for adults • Hypercarotenemia: condition caused by the accumulation of carotenoids in the adipose tissue, causing the skin to appear yellow -orange. o β-carotene supplements have been associated with an increase in lung cancer in cigarette smokers. o UL: none for carotenoids. o The small amount in a standard strengt h multivitamin supplement not likely to be harmful. Vitamin D • It is fat soluble and is known as the sunshine vitamin. o It can be made in the skin with exposure to ultraviolet light. • It is essential in the diet only when exposure to sunlight is limited or t he body’s ability to synthesize it is reduced. Vitamin D functions and deficiency • Vitamin D is inactive until it is modified by biochemical reactions in both the liver and the kidney. • Active vitamin D is needed to maintain normal levels of the minerals calcium and phosphorous in the blood. • Important in bone health and proper function of nerves, muscles, glands, and other tissues • When vitamin D is deficient, only about 10 -15% of the calcium in the diet can be absorbed. • Rickets: vitamin D deficien cy in children, characterized by narrow rib cage, known as pigeon breasts, and bowed legs. • Osteomalacia: vitamin D deficiency in adults, characterized by loss of minerals from bone, bone pain, muscle aches, and an increase in bone fractures. o Can precipitat e or exacerbate osteoporosis, which is loss of total bone mass. o Common in adults with kidney failure. • Affects cells in the pancreas, heart, skeletal muscles, and immune system. • May play a role in preventing cells from being transformed into cancerous cells . • Evidence that vitamin D may play a role in the increased risk of type 1 diabetes, multiple scle rosis, high blood pressure , inflammatory bowel disease, infections, CVD, cancer, and neurological disorders ( i.e. Alzheimer’s ). Meeting vitamin D needs • Not widespread in the diet. • Natural food sources: liver, egg yolks, and oily fish. • Fortified food sources: milk , milk substitutes , margarine, some yogurts, cheeses, and breakfast cereals. • Sunlight: major source. o Anything that interferes with the transmission o f UV radiation to the Earth’s surface or its penetration into the skin will affect the synthesis of vitamin D. ▪ Living at h igher latitudes. ▪ Those who do not spend time outside. ▪ Those who cover their skin when outside with clothing or sunscreen . • Recommended intake: 15 µg/day for age 1 -70 years; 20 µg/day for 70+ years . o Contained in about 5 cups of vitamin D -fortified milk. o Recommended intake increases with age. • Toxicity: can cause high calcium concentrations in the blo od and urine. o Deposition of calcium in soft tissues such as the blood vessels and kidneys, and cardiovascular damage. o Synthesis of vitamin D from the sun does not produce toxic amounts. o UL: 100 µg (4 000IU)/day for a ge 9+ . Vitamins: What Should I Eat? • Focu s on folate, vitamin A, and vitamin K. • B (vitamin) sure. • Get your antioxidants. • Soak up some D. Meeting Needs with Dietary Supplements • Currently about 60% of all adult Americans take a form of dietary supplement. • Can be beneficial under some circumstances but also have potential to harm . • Do not provide all of the benefits of food. o Do not provide energy, protein, minerals, fiber, or phytochemicals supplied b y food sources. Who Needs Vitamin/Mineral Supplements • Dieters: who consume fewer than 1600 Calories/day. • Vegans and those who eliminate all dairy foods. o Need adequate vitamin B12, calcium and vitamin D. • Infants and children: supplemental fluoride, vitamin D, and iron may be recommended. • Young women and pregnant women: need adequate folate and iron. • Older adults: may need vitamin B12 with atrophic gastritis; Vitamin D and calcium may be needed. • Individuals with dark skin pigmentation: may need vitamin D. • Individuals with restricted diets. • People taking medications: some medications interfere with the body’s use of some nutrients. • Cigarette smokers and alcohol users. o Smokers may require more vitamin C and vitamin E. o Alcohol consumption inhibits the absorption of B vitamins. Herbal Supplements • Herb: term generally used to refer to any botanical or plant -derived substance. • Folk medicine has used herbs to prevent and treat disease. • Readily available and relatively inexpensive. • Purchased over -the -counter. • Some are toxic, either alone or in combination with other drugs or herbs. Choose Supplements with Care • The Dietary Supplement Health and Education Act (DSHEA), 1994 defined the term “dietary supplement. o Created standards for labeling products. o Left most of the responsibility for manufacturing practices and safety in the hands of the manufacturers. o The FDA does not approve the safety and effectiveness of supplements before they are marketed. ▪ FDA must prove that the supplement represents a risk before it can require the manufacturer to remove the supplement from the market. ▪ Exception: if products contain new ingredients. Then the manufacturer must provide the FDA with safety data. ▪ U.S. Pharmacopeia (USP) Re gulations: More stringent set of manufacturing regulations o Voluntary dietary supplement verification program o If the manufacturer chooses to participate they can include the USP -verified mark on product label • Supplements are not regulated as strictly as drugs. • Safe option for multivitamin/multimineral supplement: that does not exceed 100% of the RDAs. • Suggestions for safe use: o Consider why you want it. o Compare product costs. o Read the label. o Check the expiration date. o Consider your medical hist ory. o Approach herbal supplements with caution. o Report harmful effects.
