Question 1

Keshan disease is metabolic disorder in which large amounts of copper accumulate in the liver,kidney,brain,and cornea.In parts of China,an endemic cardiomyopathy called Wilson disease is associated with severe selenium deficiency.

Accepted Answer

Both statements are false.The diseases are reversed.Keshan disease occurs in parts of China and causes cardiomyopathy due to severe selenium deficiency.Wilson disease is a metabolic disorder in which large amounts of copper accumulate in the liver,kidney,brain,and cornea.

Question 2

Approximately what percentage of copper is absorbed?

Accepted Answer

Approximately one third (33%)of copper is absorbed,with absorption occurring in the stomach and duodenum.Absorption is enhanced by a low (acidic)pH and is decreased with large amounts of calcium and zinc.

Question 3

A moderate intake of selenium has been linked to reduced risks of prostate,lung,and colon cancers and heart disease because of its role as an antioxidant.

Accepted Answer

Both the statement and the reason are correct and related.Selenium functions mainly as a cofactor for an antioxidant enzyme that protects membrane lipids,proteins,and nucleic acids from oxidative damage.It also contributes to the maintenance of normal immune function.

Question 4

Aluminum exposure increases prevalence of dental caries because this element decreases the uptake and retention of fluoride.Aluminum accumulation can occur when taking antacids containing aluminum hydroxide.

Accepted Answer

The first statement is false; the second is true.Dental caries can be reduced because aluminum enhances the uptake and retention of fluoride and enhances the cariostatic activity of fluoride.Aluminum accumulation can occur from the diet and through oral ingestion of aluminum hydroxide antacids.This is particularly pertinent for dental hygienists to appreciate because many people take antacids as calcium supplements.

Question 5

The mineral most likely to occur in shellfish,oysters,crabs,sesame,and sunflower seeds is:

Accepted Answer

Copper is widely distributed in foods.The richest sources include shellfish oysters,crabs,liver,nuts,sesame and sunflower seeds,soy products,legumes,and cocoa.Although selenium is also found in seafood and nuts,it is not found in sesame and sunflower.Molybdenum is found in nuts but not in seafood.

Question 6

Chromium supplements can cause serious renal impairment when taken in excess.Registered dietitians frequently recommend over-the-counter chromium supplements for weight loss and type 2 diabetes management.

Accepted Answer

The first statement is true; the second is false.Currently,the evidence is unclear that any type of supplemental chromium can help with fat loss or enhance lean body mass.More research is needed regarding the use of chromium supplements to manage glycemic control in diabetes.

Question 7

Which is the best advice a dental hygienist can give a patient concerning ingestion of trace elements?

Accepted Answer

Consumption of a variety of foods and fluids can help patients to obtain trace minerals and avoid excessive amounts.Supplements of trace elements are not encouraged.Unrefined foods generally provide more trace minerals than highly refined foods do.

Question 8

Each is considered an ultratrace element,except one.Which is the exception?

Accepted Answer

Molybdenum is a trace,not ultratrace,element.Ultratrace elements include boron,nickel,silicon,tin,aluminum,lead,lithium,vanadium,and mercury.Note that aluminum and mercury are not nutrients because they provide no beneficial effect to the body.

Question 9

Each accurately describes aspects and treatment of Alzheimer disease,except one.Which is the exception?

Accepted Answer

An earlier hypothesis that aluminum toxicity might cause Alzheimer disease is now considered inaccurate.Brain lesions and neurotransmitter changes seem in aluminum toxicity differ from those in Alzheimer disease.In contrast to the subtle cognitive changes associated with Alzheimer disease,aluminum toxicity manifests with motor dysfunction.Vitamin E is frequently advised because its antioxidant properties may protect nerve cells from certain kinds of chemical wear and tear.It should only be used under guidance of a health care provider.

Question 10

Each is true of physiologic roles and reactions to selenium,except one.Which is the exception?

Accepted Answer

Large amounts of selenium during tooth formation can be detrimental to the mineralization process.Animal studies indicate excessive selenium can promote dental caries when given before eruption; however,moderately high levels seem to have some cariostatic effects.

Question 11

High doses of zinc supplements increase copper absorption.Large amounts of vitamin C supplements increase bioavailability of copper.

Accepted Answer

Both statements are false.High doses of zinc supplements decrease,not increase,copper absorption,possibly leading to anemia-related fatigue.Large amounts of vitamin C supplements decrease serum bioavailability of copper.Also pertinent,excess molybdenum produces a copper deficiency.

Question 12

Which seafood is most likely to have the least amount of mercury?

Accepted Answer

Salmon is considered the safest seafood listed in the question.Note that canned tuna is likely to have less mercury than fresh tuna.Large,older fish higher up on the food chain such as shark,swordfish,king mackerel,and tilefish are the leading source of mercury in the diet.Note that although mercury is an ultratrace mineral,it is not a nutrient because of its inherent toxicity.Even trace amounts can cause neurologic and developmental problems in infants and young children.

Question 13

Copper deficiency causes lesions within connective tissues and bone.Copper has little to no measurable effect on enzyme synthesis and activity.

Accepted Answer

The first statement is true; the second is false.Copper deficiency causes a variety of lesions within connective tissues and bone,resulting in failure to grow (in children),spontaneous fractures,osteoporosis,arthritis,and arterial disease.Inadequate copper intake is associated with decreased or altered enzyme synthesis and activity.

Question 14

Which element is most likely to be found in a patient with extreme nausea,menopausal symptoms,and rheumatoid arthritis?

Accepted Answer

Copper taken orally is an emetic,which is a substance that induces vomiting.Ten milligrams of copper can induce nausea.Patients with rheumatoid arthritis have elevated serum levels of copper.Serum copper levels are elevated in patients with rheumatoid arthritis,myocardial infarction,conditions requiring administration of estrogen,and pregnancy.

Question 15

Aluminum,an essential nutrient,is added to intravenous solutions because it increases absorption and distribution of the medications.

Accepted Answer

Neither the statement nor the reason is correct.Although aluminum is present in many body tissues,including all dental tissues,it is not considered an essential element because its presence seems harmful.A particular concern is that water used in intravenous solutions and dialysis fluid is sometimes contaminated with aluminum.The inability of the kidneys to remove aluminum has prompted reformulation of these solutions; however,aluminum content may still be high because of naturally occurring aluminum in the water used to make the solutions.

Question 16

Which mineral is most closely associated with insulin metabolism?

Accepted Answer

Chromium is involved in carbohydrate and lipid metabolism,especially in the use of glucose.Chromium potentiates the action of insulin and can facilitate insulin in assisting cells in glucose uptake and energy release.Supplementation can improve systemic insulin sensitivity,but the use of chromium supplements for individuals with diabetes is controversial.

Question 17

Each is true of chromium,except one.Which is the exception?

Accepted Answer

Chromium status decreases,not increases,with age.This suggests that older individuals may be at high risk of deficiency.Chromium is involved in carbohydrate and lipid metabolism,especially in the use of glucose.Chromium potentiates the action of insulin and can facilitate insulin in assisting cells in glucose uptake and energy release.

Question 18

Each is a physiologic role of copper,except one.Which is the exception?

Accepted Answer

Copper is not a cofactor for an antioxidant enzyme; selenium is.Neurotransmitters that benefit from copper-containing enzymes include norepinephrine and dopamine.Epidemiologic data suggest that a deficiency of copper is cariogenic,but bacteriological studies cite copper as having cariostatic abilities to reduce acidity of plaque.

Question 19

Each is true of the effects of lead,except one.Which is the exception?

Accepted Answer

Milk intake results in reduced lead absorption.Note that infants and children are more susceptible to detrimental effects of lead absorption because it is more readily absorbed during early years.Although the effects of lead in bones and teeth are unknown,elevated serum (blood)levels may be associated with periodontitis.

Question 20

Acidic foods such as pineapple and tomato packed in uncoated tin cans contain significant amounts of tin.Most Americans consume high amounts of tin because most foods contain moderate to high level of it.

Accepted Answer

The first statement is true; the second is false.Most Americans consume only small amounts of tin daily because most foods contain trace amounts of tin.Foods packed in tin cans that are totally coated with lacquer contain very little tin.Acidic foods packed in uncoated cans contain significant amounts of tin.Other sources of tin include stannous chloride,a food additive,and stannous fluoride,the active ingredient in some dentifrices and mouth rinses.

Quiz 10: Nutrients Present in Calcified Structures