7: Nutrition

CHAPTER 7 Nutrition

NUTRIENTS AND DEFICIENCIES

Nutrients are substances obtained from food and promote growth, maintenance, or repair. Six classes of nutrients include macronutrients (biomolecules) of proteins, carbohydrates, and lipids, as well as vitamins, minerals, and water. For Acceptable Macronutrient Distribution Ranges (AMDRs), adults should obtain 10% to 35% of calories from protein, 45% to 65% from carbohydrates, and 20% to 35% from lipids (fat). Acceptable ranges for children are SIMILAR, except that infants and younger children need higher proportion of fat (25% to 40%).

For vitamins and minerals, Dietary Reference Intakes (DRIs), issued by the Institute of Medicine of the National Academy, are the average daily dietary intake level sufficient to meet nutrient requirements of nearly ALL (~98%) healthy individuals (includes Recommended Dietary [Daily] Allowance [RDA]) (Table 7-1). RDIs (Reference Daily Intakes) and DVRs (Daily Recommended Values) are comparable standards and can be combined to create DVs (Daily Values), as published by the FDA.

Table 7-1 Acceptable macronutrient distribution ranges (AMDRs) and dietary reference lntakes (DRIs) for adults per day∗

Macronutrient Females Males
Protein 46 g 56 g
Carbohydrates 130 g Same
Lipids None Same
Vitamin A (retinol) 700 μg 900 μg
Vitamin D 5 μg (AI)† Same
Vitamin E 15 mg‡ Same
Vitamin K 90 μg (AI) 120 μg
Thiamine (vitamin B1) 1.1 mg 1.2 mg
Riboflavin (vitamin B2) 1.1 mg 1.3 mg
Niacin (vitamin B3) 14 mg 16 mg
Pantothenic acid (vitamin B5) 5 mg (AI) Same
Pyridoxine (vitamin B6) 1.3 mg Same
Cobalamin (vitamin B12) 2.4 μg Same
Vitamin C (ascorbic acid) 75 mg§ 90 mg§
Biotin 30 μg (AI) Same
Folate (folacin, folic acid) 400 μg Same
Calcium 1000 mg (AI) Same
Phosphorus 700 mg Same
Magnesium 310 mg 400 mg
Sodium 500 mg Same
Chloride 750 mg Same
Potassium 2000 mg Same
Sulfur None Same

AI, Adequate intake.

∗ Includes adequate intake or Estimated Average Requirement (EAR), where NO DRI has been established, expected to satisfy needs of 50%.

† 5 μg = 200 IU (International Units).

‡ Tolerable upper intake limit (UL) is 1000 mg/day.

§ Smokers should add 35 mg to these values.

Malnutrition is an imbalance between nutrients the body needs and nutrients it receives. Includes overnutrition (consumption of too many calories or too much of specific nutrient) and undernutrition (deficiency MAINLY of calories or protein). Deficiencies of vitamins and minerals are usually considered separate disorders. When calories are deficient, however, vitamins and minerals are also likely to be. Calorie or kilocalorie (kcal) is a unit of measurement for energy, in this case food energy. Energy is measured by heat expenditure; 1 kilocalorie is the amount of heat produced to raise temperature of 1 kilogram of water 1° C.

image • See CD-ROM for Chapter Terms and WebLinks.
• See Chapters 3, Anatomy, Biochemistry, and Physiology: biomolecules; 6, General Pathology, and 16, Special Needs Patient Care: nutrition-related conditions and diseases.

Proteins

Proteins are organic compounds that are composed of amino acids, building blocks of proteins. Contain carbon, hydrogen, oxygen, nitrogen. MAIN function is to build tissue and replace cells. Presence of proteins affects ALL body activities.

A. Types:

1. Amino acids (20) held together by peptide bonds; carboxyl (COOH) group of one amino acid is linked to an amino (NH2) group of another.

a. The 9 essential (indispensable) amino acids (EAAs) CANNOT be synthesized by the body and must be obtained from the diet; nitrogen balance can be achieved from proper proportions and adequate amounts of these.
b. The 11 nonessential (dispensable) amino acids (NEAAs) can be synthesized by the body ONLY when nitrogen is present.

2. Complete proteins (high-quality): foods that consist of ALL the essential amino acids in sufficient amounts; completely supply the needs of the body for maintenance, repair, and growth; are found in meat, fish, poultry, eggs, cheese, milk.
3. Incomplete proteins (low-quality): foods that lack one or more essential amino acids; include plant proteins; when ONLY food eaten, can support life but NOT normal growth.
4. Complementary proteins: two or more proteins that combine to compensate for deficiencies in amino acid content; use of whole grains IMPORTANT.

B. Physiology and metabolism of proteins: see Chapter 3, Anatomy, Biochemistry, and Physiology
C. Functions of proteins:

1. Role in overall body needs; assist in growth, maintenance, construction, and repair of body tisue.
2. Provide essential components of hormones and enzymes and provide precursors of antibodies.
3. Provide energy source when carbohydrate and fat intake is inadequate: 4 kcal per gram (g).
4. Regulate acid-base balance.

D. Role in oral health:

1. Essential for cell growth; thus IMPORTANT in growth and development of the oral cavity.
2. Maintain pulp.
3. If absent, result is crowded and/or rotated teeth because of inadequate growth of bone.
4. Deficiency can lead to disturbances in tooth development such as with kwashiorkor or marasmus (see later discussion) or damage to the periodontium (as with kwashiorkor).
5. Can help neutralize acids produced by dental biofilm (dental plaque).

E. Role in periodontal health or disease:

1. IMPORTANT in maintaining health of periodontium.
2. Essential for cellular defenses against bacteria in subgingival dental biofilm.
3. Essential for healing and repair of tissue after periodontal trauma or surgery.

F. Dietary requirements for proteins: 0.8 g per kg of body weight for adults:

1. DRI for adults: 46 g (female) and 56 g (male) per day.
2. Increased during periods of growth, pregnancy, lactation.
3. Increased during episodes of trauma, fear, anxiety, surgery, fever.

G. Nutrient sources of proteins:

1. Complete proteins: meat, fish, poultry, eggs, milk.
2. Incomplete proteins: legumes, grains, vegetables, soybeans.

H. Nutritional deficiency and diseases related to proteins:

1. Phenylketonuria (PKU):

a. Liver CANNOT metabolize essential amino acid phenylalanine into nonessential amino acid tyrosine.
b. Toxic by-products build up in the body and damage developing nervous system of infant, causing intellectual disability (mental retardation).
c. Managed by restricting phenylalanine to only enough to support normal growth; supplement tyrosine; avoid aspartame (Nutrasweet, Equal).

2. Protein-energy (calorie) malnutrition (PEM, PCM) or undernutrition:

a. Marasmus: inadequate food intake; MOST common in children 6 to 18 months of age in impoverished nations; impairs brain development and learning; MAINLY causes severe wasting and weakening of muscles; NO edema.
b. Kwashiorkor: severe protein deficiency even with calories from carbohydrates; begins at approximately 2 years; WITHOUT severe wasting of body fat; symptoms include apathy, failure to grow and gain weight, listlessness, changes in hair color, edema in abdomen and legs (causes swelling); associated with necrotizing periodontal disease (Figure 7-1).
c. Starvation: MOST extreme form of marasmus (and undernutrition), results from partial or total lack of essential nutrients for a long time (see self-starvation under patient with eating disorder).
d. Cachexia: severe wasting away of muscle and fat tissue as a result of excessive production of substances called cytokines, produced by immune system in response to a disorder; MOST common with cancer and AIDS.
e. Adult PEM (PCM): alcoholics (with nutritional liver disease), long-term bedridden or hospital patients, persons taking certain drugs that decrease appetite (diuretics) or increase metabolism (thyroxine).

(1) Oral effects of PEM (PCM):

(a) Tooth development decreased.
(b) Salivary composition and flow affected.
(c) Connective tissue and bone development affected.
(d) Acid production increased.

3. Overconsumption of proteins (e.g., Atkins diet, with low carbohydrates):

a. May affect calcium balance if inadequate calcium.
b. Increase in water consumption.
c. Additional fat stores.
d. Stress to liver and kidneys owing to presence of excess ketones, especially if already damaged.
e. Halitosis.

4. Possible deficiency in poorly planned strict vegan diets (consisting ONLY of plant foods); adequate as long as caloric intake is adequate and variety of foods is eaten.

a. Easier to achieve with diets that include dairy products and eggs (lacto-ovo-vegetarian).
b. Harder to achieve with diets consisting ONLY of fruits and vegetable oils (fruitarian diets).

image

Figure 7-1 Kwashiorkor is a severe protein deficiency even with calories from carbohydrates, without severe wasting of body fat, but with apathy, failure to grow, and edema.

Carbohydrates

Carbohydrates are organic compounds (contain carbon) that also contain the elements hydrogen and oxygen. Provide energy during metabolism (you burn 20 calories per hour chewing gum).

A. Types of carbohydrates:

1. Simple carbohydrates:

a. Monosaccharides (single sugars):

(1) Pentoses (C5) act as coenzymes in energy production (e.g., ribose, deoxyribose).
(2) Hexoses (C6) have MAJOR nutritional importance.
(3) Glucose (blood sugar or dextrose) is the form used MOST efficiently by the body; obtained from ALL plant carbohydrates; serves MAINLY as fuel for the brain; found in honey, fruits, corn syrup; however, ALL sugars are converted to glucose, so do NOT need these to feed the brain.
(4) Fructose (levulose, fruit sugar) is the sweetest of ALL sugars; closely related to glucose structurally; found in honey, fruits, corn syrup; changed to lactic acid by Streptococcus mutans.
(5) Galactose, derived from hydrolysis of lactose; constituent of many plant polysaccharides; during lactation, body converts glucose to galactose in mammary tissue to synthesize lactose in breast milk.

b. Disaccharides (double sugars; two monosaccharides):

(1) Lactose (milk sugar) is composed of glucose and galactose; obtained from milk products.
(2) Sucrose (table sugar; cane and beet sugar) composed of glucose and fructose; obtained from sugar beets, sugarcane, or maple syrup.
(3) Maltose (plant sugar) is composed of two molecules of glucose; forms as starch in grains and breaks down during germination; ferments alcohol.

2. Complex carbohydrates (long chains of sugars):

a. Polysaccharides:

(1) Starch (mixture of amylose and amylopectin) is the MOST important carbohydrate. Digestible by humans; stores energy in plants; breaks down at slower rate than monosaccharides and disaccharides; found in rice, wheat, corn, rye, potatoes, legumes.
(2) Glycogen is the animal equivalent of starch; provides food storage system for ALL forms of animal life; stored in liver, where it regulates blood sugar, and in muscle, where it serves as an energy source for muscle contraction.
(3) Insulin is produced by pancreas; stores energy.
(4) Dextran forms a substrate for dental biofilm (dental plaque); serves as energy source for dental caries–producing bacteria such as Streptococcus mutans; makes dental biofilm sticky.

b. Fibers:

(1) Cellulose: provides fibrous framework for plants; good source of fiber; NOT digestible and therefore provides roughage and bulk to aid in peristalsis and elimination of water; found in fruits, legumes, ALL vegetables.
(2) Hemicellulose: group of fibers that are insoluble (do NOT easily dissolve in water); MAIN constituent of cereal fibers.
(3) Pectin: responsible for thickening of jams and fruit preserves; keeps salad dressing from separating; found in vegetables and fruits, especially citrus fruits and apples.

B. Physiology and metabolism of carbohydrates: see Chapter 3, Anatomy, Biochemistry, and Physiology.
C. Functions of carbohydrates:

1. Provide energy (4 kcal/g).
2. Spare proteins so they can supply energy when necessary, but MAIN function is to build tissue, replace cells.
3. Aid in oxidation (burning) of fats to prevent ketosis (partial fat breakdown; leads to increased ketone levels in bloodstream).
4. Furnish fiber for peristalsis; also provide bulk, reduce risk of cardiovascular disease, prevent constipation and diverticular disease.
5. Aid in formation of intercellular substance (ground substance) and collagen.
6. Aid in formation of nonessential amino acids.

D. Dietary requirements for carbohydrates:

1. DRI: 130 g/day; infants require MORE carbohydrates to prevent use of protein for energy.
2. Maximum intake level of ≤25% from added sugars.
3. Dietary fiber recommended intake: ≤50 years 25 g (female) and 38 g (male)/day; >50 years is 30 and 21 g/day, respectively, owing to decreased food consumption.

E. Nutrient sources of carbohydrates:

1. Milk, cereals, breads provide starch.
2. Leafy vegetables provide cellulose and hemicellulose.
3. Vegetables such as root tuber and seed (potatoes, beans, beets, squash) provide starch and sucrose.
4. Fruits provide MAINLY glucose and fructose.
5. Sugar, honey, corn syrups provide monosaccharides and disaccharides.
6. Sweeteners:

a. Sucrose: disaccharide found in table sugar, beet sugar, cane sugar.
b. High-fructose corn syrup (HFCS): 40% to 90% fructose; made by treating corn starch with acid and enzymes to break it down into glucose, which then is changed into fructose; possibly tied to obesity.
c. Turbinado sugar: partially refined version of raw sugar; has a slight molasses flavor.
d. Brown sugar: white sugar that contains some molasses; molasses is either added or not totally removed.
e. Maple syrup: boiled sap from sugar maple trees.

7. Alternative sweeteners:

a. Sugar alcohols are sugarlike compounds (nutritive sweeteners) that, like carbohydrates, yield 4 kcal/g of energy; metabolized MORE slowly than sucrose by bacteria in the mouth and therefore do NOT promote caries; CANNOT be used at same time as disulfiram (Antabuse) prescribed for treatment of alcohol abuse and alcohol dependence.
b. Xylitol: derived from cellulose products such as wood straw or pulp cane; may produce diarrhea when taken in excess; equivalent to sucrose in sweetness; used in sugarless gums and foods, since does NOT promote caries; also reduces bacterial tooth adherence and secretion of acids and promotes tooth remineralization; must follow manufacturer’s instructions when used for anticaries purposes.
c. Sorbitol: from glucose by hydrogenation; used in foods, especially diabetic foods and sugarless gums; NOT readily absorbed by the small intestine and therefore can cause diarrhea.
d. Mannitol: from mannose and galactose by hydrogenation; used in sugarless gums and candies; NOT readily absorbed by the small intestine; may cause diarrhea.

8. Artificial sweeteners include noncarbohydrate, noncaloric, or low caloric:

a. Sucralose (Splenda): 600 times sweeter than sucrose, twice as sweet as saccharin and four times as sweet as aspartame; stable under heat and can be used in baking and products that require longer shelf-life; NOT recognized by body as carbohydrate, so does NOT affect blood glucose levels or insulin response (useful for diabetics); essentially inert molecule that passes through body without being broken down for calories.
b. Aspartame (Nutrasweet, Equal): composed of two amino acids (phenylalanine and aspartic acid) and methanol; used ONLY in beverages, gelatin desserts, and sugarless gum; CANNOT be used in baking (low-calorie sweetener yields 4 kcal/g).
c. Saccharin: derived from coal-tar compounds; 500 times sweeter than sucrose; widely used in soft drinks and table sweeteners; may cause cancer, and therefore products must contain a warning label.
d. Acesulfame-K: 200 times sweeter than sucrose; used in sugarless gum, powdered drink mixes, gelatin puddings, nondairy creamers; can be used in baking.

F. Nutritional management of disease and deficiency related to carbohydrates. See Chapter 6, General and Oral Pathology.

1. Diabetes mellitus (DM): metabolic endocrine disorder with high blood glucose level as result of insufficient or ineffective insulin function; results in tissue damage; diet considerations will be guided by diabetic nutrition counselor.

a. Non-insulin-dependent (MAINLY type 2):

(1) Restrict calories and reduce weight.
(2) Engage in regular exercise (assists muscles in taking up MORE glucose).
(3) Space meals evenly throughout the day.
(4) Avoid alcohol consumption.

b. Insulin-dependent (MAINLY type 1):

(1) Requires careful nutritional assessment; SHOULD eat regular meals with precise carbohydrate-to-protein-to-fat ratio.
(2) Intensive insulin therapy, including regular blood glucose monitoring.
(3) Regular exercise.

2. Reactive hypoglycemia (low blood glucose levels):

a. Occurs in reaction to ingestion of food, 1 to 4 hours after meal:

(1) Initial symptoms include weakness, rapid heartbeat, sweating, anxiety, hunger; caused by release of epinephrine (hormone), which is triggered by falling blood glucose level.
(2) Fasting sets in gradually and affects the brain and central nervous system (CNS); symptoms then include headache, fatigue, blurred vision, confusion; are NOT related to epinephrine release.

b. Prevention: eat regular meals with protein, fat, complex carbohydrates that contain soluble fiber; AVOID concentrated sweets.
c. Management: eat balanced meals at regular intervals (this is the diet for NDHBE time!).

3. Lactose intolerance: intestinal condition with reduced lactose digestion because of deficiency of digestive enzyme lactase, which hydrolyzes lactose to glucose and galactose in the intestine.

a. When lactase is absent in small intestine, lactose travels to large intestine, where bacteria break it down into gas and acids.
b. Symptoms: cramps, abdominal distention, gas symptoms, diarrhea after consumption of dairy products.
c. Management:

(1) Eat smaller servings of milk products.
(2) Include fat in meals; slows digestion and leaves MORE time for lactase action.
(3) Eat cheese; lactose is lost when milk is processed into cheese.
(4) Consume yogurt with active bacteria cultures; lactose is digested by yogurt.

4. Dental caries:

a. Dental biofilm (dental plaque) bacteria break down sucrose and glucose into lactic acid as result of enzymatic activity of streptococci and lactobacilli.

(1) Streptococcus mutans initiates process; synthesizes polysaccharides (glycogen, dextran, levan) for future fermentation.

(a) Polysaccharides are used for energy when needed.
(b) Dextrans form substrate and serve as energy source.
(c) Demineralization begins at 5.5 pH.

(2) Lactobacillus acidophilus extends process.

b. Fermentable carbohydrate ingestion: concentration of sugars in food is KEY factor in caries development.

(1) Sugar-rich foods: cariogenic activity of sucrose, glucose, fructose is similar; physical form of food also affects activity (oral clearance time of liquids is faster than that of solids and retentive sweets; thus sugared liquids are generally less cariogenic).
(2) Concentration of 0.8 M must be present for sugar to pass through 1 mm of dental biofilm and undergo harmful fermentation (e.g., 1-M solution of sugar contains 342.3 g of sugar in water).
(3) Starch-rich foods: if left on teeth for long periods, will degrade to organic acids and can contribute to acid levels.

c. Salivary flow rate: inadequate salivary flow (e.g., xerostomia) interferes with oral clearance time of cariogenic foods, decreasing natural salivary buffers and initiating caries development.
d. Daily food intake frequency: development related to between-meal snacking; eating sweets with a meal makes them less cariogenic.

CLINICAL STUDY

Scenario: The 8-year-old patient is in the dental office for a 6-month oral prophylaxis maintenance appointment. When asked more about the child’s health, the mother said the girl even wet her bed a couple of nights ago. The mother also notes that she has recently had an increased appetite yet has lost weight. “My daughter had a severe chest cold about 2 months ago and now she is waking up frequently during the night to urinate.”

1. What is the most likely diagnosis of the patient’s condition?
2. Identify the usual causes and predisposing factors for this condition.
3. What is the best treatment plan for this condition?
4. Is this condition preventable? And if so, how?
5. What type of nutritional management would be recommended for the patient?

1. Type 1 diabetes mellitus (DM).
2. Condition that may trigger onset of type 1 DM is a viral infection. Infection may affect immune response that attacks the pancreas, leading to inability to make insulin. Symptoms include polyuria (frequent urination), increased appetite (polyphagia), thirst (polydipsia), weight loss.
3. Treatment plan would include insulin therapy, regular blood glucose monitoring, careful nutritional assessment.
4. DM cannot be prevented but can be controlled by drugs and diet. Although viral infection may play a part in the development of type 1 DM, its determination as a cause cannot always be made.
5. The patient requires careful nutritional assessment by a diabetic nutrition counselor; should eat regular meals with precise carbohydrate-to-protein-to-fat ratio; needs intensive insulin therapy, including regular blood glucose monitoring and regular exercise.

Lipids

Lipids (fats) are organic compounds composed of carbon, hydrogen, oxygen. Types include triglycerides (fats and oils), phospholipids, sterols (cholesterol). MAIN function is to provide energy.

A. Types of lipids:

1. True fats are composed of glycerol (trihydroxy alcohol) that is attached to one, two, or three fatty acids to form monoglycerides, diglycerides, or triglycerides, respectively.

a. Saturated fatty acid carries maximum number of hydrogen atoms; remains solid at room temperature; increases serum cholesterol.

(1) Stearic acid in beef and lard.
(2) Palmitic acid in animal fat and palm oil.
(3) Myristic and lauric acid in coconut oil.

b. Monounsaturated fatty acid contains a point of unsaturated linkage (with NO hydrogen atom); viscous in form; NO effect on serum cholesterol.

(1) Oleic acid sources include olive oil, shortening, lamb, canola oils.

c. Polyunsaturated fatty acid contains two or more points of unsaturation; liquid in consistency (includes oils); decreases serum cholesterol.

(1) Omega-6 fatty acids are linoleic; found in corn, cottonseed, safflower, and sunflower oils, tofu.
(2) Omega-3 fatty acids are linolenic; found in fatty fish oils, green leafy vegetables, soybean products (tofu).

d. Essential fatty acids (i.e., linoleic and linolenic acids) must be obtained from diet; regulate blood pressure, assist in clot formation, maintain cell membranes, make hormonelike substances, support functioning of the retina.

2. Compound lipids are compounds added to glycerol and fatty acids.

a. Phospholipids are built on backbone of glycerol, with one fatty acid replaced by a compound that contains phosphorus.

(1) Lecithin is found in cells and participates in fat digestion in the intestine; acts as an emulsifier by mixing oil with water (e.g., in salad dressings, mayonnaise); found in egg yolk.

b. Lipoproteins are produced in the liver and allow cholesterol, triglycerides, phospholipids to be transported in the bloodstream.

(1) Chylomicrons are made in the intestine after fat absorption; contain triglycerides and a small amount of protein.

(a) Transport newly absorbed lipids from intestinal cells to the bloodstream by way of the lymphatic system.
(b) During circulation, cells remove lipid content and therefore become smaller.
(c) Liver picks up and breaks down chylomicrons and assembles new lipoproteins known as very low-density lipoproteins (VLDLs).

(2) VLDLs: the liver coats cholesterol and triglycerides with a shell of protein and lipids.

(a) VLDLs leave the liver, and triglycerides are broken down into fatty acids and glycerol by the enzyme lipase.
(b) VLDLs become much heavier as triglycerides are released.
(c) VLDLs gather cholesterol from other lipoproteins and become low-density lipoproteins (LDLs).

(3) Low-density lipoproteins (LDLs): composed MOSTLY of cholesterol; contain a few triglycerides; larger, lighter, MORE lipid filled than VLDLs (“bad guys”) (see note with nicotinic acid later).

(a) Cells absorb LDLs from the bloodstream and break them down;
MOST LDLs are taken up by liver cells when a diet is low in saturated fats and cholesterol.
(b) Scavenger cells in blood vessels engulf LDLs that are NOT taken up;
over time, cholesterol builds up on inner blood vessel walls and plaque develops.
(c) Blood supply to organs is subsequently cut off (ischemia), which may result in cardiovascular disease (CVD), myocardial infarction (MI, heart attack), or cerebrovascular accident (CVA, stroke).

(4) High-density lipoproteins (HDLs): produced by liver and intestine; smaller, denser; contain high amount of protein (“good guys”).

(a) HDLs travel in the bloodstream and pick up cholesterol.
(b) Cholesterol is transported by way of other lipoproteins back to liver for excretion.
(c) High HDL levels slow development of CVD.

3. Cholesterol (sterol):

a. Capable of forming esters with fatty acids.
b. Makes IMPORTANT hormones (estrogen, testosterone).
c. Makes bile, emulsifier needed for digestion.
d. Found ONLY in animal foods.
e. Liver can make what the body needs; high levels raise total plasma cholesterol level.

4. Fat replacements (artificial fats):

a. Olestra: made by adding fatty acids to sugar; yields NO energy to the body; may lower blood serum cholesterol levels; reduces absorption of vitamin E; has NO kilocalories; may cause diarrhea.
b. Simplesse: whey protein product; feels like fat in the mouth but contains NO fatty acids; CANNOT be used in cooking; contains 1.3 kcal/g.
c. Hydrogenation: process that reduces amount of fat per serving (e.g., diet margarine).
d. Gums: derived from plant sources and added to thicken products such as diet salad dressings.

B. Physiology and metabolism of lipids: see Chapter 3, Anatomy, Biochemistry, and Physiology, and Chapter 9, Pharmacology, for control of LDLs.
C. Functions of lipids:

1. Provide energy (9 kcal/g) (used for energy by body after readily available carbohydrates are used up).
2. Store energy.
3. Insulate to maintain body temperature and protect organs.
4. Transport fat-soluble vitamins to small intestine and aid in absorption.
5. Produce satiety (feeling of fullness).
6. Provide flavor and texture to foods.

D. Dietary requirements of lipids: ≤25% to 35% of total kcal (AMDR); NO DRI.

1. Saturated: <10% total kcal.
2. Monounsaturated: ~10% total kcal.
3. Polyunsaturated: ~10% total kcal.
4. Essential fatty acids: 1% to 3% total kcal.
5. Cholesterol: ≤300 mg/day.

E. Nutrient sources of lipids:

1. Saturated: animal fat and palm oil.
2. Monounsaturated: olive oil, shortening, lamb.
3. Polyunsaturated: soybean, cottonseed, and vegetable oils.
4. Cholesterol: animal foods.
5. Essential fatty acids: vegetable oils; recommendation is 1 tablespoon per day.

F. Nutritional management of deficiency and disease related to lipids:

1. Atherosclerosis: degenerative disease that produces hardening of large and medium arteries.

a. Formation of plaques:

(1) Includes formation of atheromata, deposits on inner walls of arteries.
(2) With age, plaque becomes fibrotic and narrows blood vessels.
(3) Eventually ischemia occurs, leading to decreased blood supply, development of CVD with complications.

b. Risk factors:

(1) Total blood cholesterol >240 mg/100 mL.
(2) LDL cholesterol >160 mg/100 mL.
(3) HDL cholesterol <35 mg/100 mL.
(4) Men >45 years; women >55 years.
(5) Smoking and family history.
(6) Hypertension.

c. Management:

(1) Reduce saturated fat in diet (intake <10% of total kilocalories lowers LDL cholesterol level); maintain polyunsaturated and monounsaturated fat intake at ~10% of total kilocalories.
(2) Increase consumption of dietary fiber (20 to 35 g per day).
(3) Lose weight; then maintain desirable body weight.
(4) Stop smoking.
(5) Eat LESS cholesterol (<300 mg per day).
(6) Replace foods rich in animal fat, butter, coconut oil, hydrogenated (solid) fat with LESS hydrogenated forms; low-fat (or fat-free, nonfat in some cases) food recommendations:

(a) Meat, fish, poultry: lean cuts; trim fat; grill, roast, or bake; tuna packed in water.
(b) Dairy: low-fat or nonfat milk, cheese, yogurt, nonfat frozen yogurt.
(c) Fruits and vegetables: nonfat salad dressing; steamed vegetables; fruit for dessert.
(d) Breads and cereals: jelly on bread instead of butter or margarine; avoid croissants, coffee cake, sweet rolls.

2. Obesity (see weight control section):

a. Decrease fat and calorie intake.
b. Excess weight of 30% increases risk of CVD, high blood pressure (HBP), DM, cancer.

Vitamins

Vitamins are organic nutrients needed by the body in small quantities. They do NOT contribute energy to the body but are facilitators of body processes. Fat-soluble vitamins include A, D, E, and K; water-soluble vitamins include the Bs and C. Note that DRI is for adults.

A. Fat-soluble vitamins: soluble in fats and fat solvents; mineral oils interfere with absorption; NOT readily excreted and so can build up to toxic levels; stored in liver and fatty tissues:

1. Vitamin A (retinol):

a. Function:

(1) IMPORTANT for night vision; retinol forms rhodopsin (visual pigment).
(2) Facilitates transcription of DNA to RNA.
(3) Antioxidant properties help prevent damage to cells by free radicals.
(4) Necessary for immune defenses.
(5) Promotes normal growth and development.
(6) Facilitates absorption of calcium at intestine.
(7) Assists in maintenance of epithelial cells such as those of oral mucosa.
(8) Assists in formation of ameloblasts and odontoblasts.

b. DRI: 700 micrograms (μg or mcg) (female) and 900 μg (males).
c. Nutrient sources:

(1) Preformed vitamin A (retinoids; animal form) is found in liver, body fat of fish, egg yolk, butter, cheese, cereal, crackers, vitamin A–fortified milk.
(2) Provitamin A (carotenoids; from plant-derived precursor carotene) is converted in body to vitamin A; MOST potent form is beta-carotene (antioxidant); found in orange-yellow and dark green fruits and vegetables (e.g., carrots, spinach, apricots, broccoli).

d. Nutritional deficiency and disease: night blindness (nyctalopia); dry, rough skin or dry oral mucosa; glossitis; pulp calcification; enamel hypoplasia; defective dentin; acne and skin problems treated with isotretinoin (Accutane), which can dry oral cavity.
e. Toxicity: irritability; enlarged liver and spleen; dry skin; bone and joint pain; xerostomia; damage to red blood cells (RBCs) and lysosomes; increased risk of hip fractures because of stimulation of osteoclasts and inhibition of osteoblasts.

2. Vitamin D (calciferol):

a. Functions as a hormone:

(1) Absorbing calcium and phosphorus.
(2) Promoting mineralization of teeth and bones.
(3) Regulating proper serum levels of calcium and phosphorus.

b. DRI: 5 μg (adequate intake [AI]).
c. Nutrient sources:

(1) Sunlight: liver makes a vitamin D precursor (7-dehydrocholesterol) that surfaces on the skin, is activated by sunlight, and is converted into vitamin D3 (cholecalciferol).
(2) Ultraviolet light.
(3) Fortified milk, butter, cod-liver oil, fatty fish.
(4) Vitamin D2 (ergocalciferol): derived from plants, especially yeasts and fungi.

d. Nutritional deficiency and disease:

(1) Rickets in children: softening of the bones (failure to calcify normally); bowed legs; enlarged head, joints, rib cage; deformed pelvis.
(2) Osteomalacia in adults: calcium is taken from bones to make up for insufficient absorption by the intestine; bowed legs, bent posture, and pain in ribs, pelvis, legs.

e. Toxicity: occurs with high blood calcium levels; nausea, weight loss, constipation, weakness, vomiting, loss of appetite, mental confusion.

3. Vitamin E (tocopherol):

a. Functions:

(1) Antioxidant: prevents oxidation of vitamin A, beta-carotene, vitamin C, unsaturated fatty acids.
(2) Protects RBCs from damage.
(3) Necessary for neural and muscular structure.
(4) Necessary for cellular respiration.

b. DRI: 15 mg/day, 1000 mg/day upper limit (UL); NO proven need for supplementation.
c. Nutrient sources:

(1) Plant (vegetable) oils: safflower, cottonseed, peanut.
(2) Green leafy vegetables.
(3) Legumes, nuts, whole grains.
(4) Apricots, apples, peaches.

d. Nutritional deficiency and disease: erythrocyte hemolysis (breakdown of RBCs), anemia.
e. Toxicity: relatively safe; increased levels may lead to increased bleeding, especially in those prone (drugs, medical history, etc.).

4. Vitamin K:

a. Function: synthesizes blood-clotting factor prothrombin (PT).
b. DRI: 90 μg (AI) (female) and 120 μg (male)/day.
c. Nutrient sources: green leafy vegetables; meat and dairy; also synthesized by intestine.
d. Nutritional deficiency: hemorrhage; for females, reduced bone mass.
e. Toxicity: eating large amounts in foods can counteract benefits of blood-thinning agents such as warfarin (Coumadin), heparin, or aspirin for CVD.

B. Water-soluble vitamins: easily excreted; LESS likely to reach toxic levels; NOT stored in body; need daily amounts.

1. Thiamin (B1):

a. Functions:

(1) Essential in metabolism of carbohydrates />

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Jan 1, 2015 | Posted by in Dental Hygiene | Comments Off on 7: Nutrition

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