CG

Nutrition and Diet Therapy - Comprehensive Notes (Ch 1-3)

CHAPTER 1 INTRODUCTION

  • LESSON 1: INTRODUCTION TO NUTRITION, HEALTH AND FOOD

  • NUTRITION

    • The study of food and how the body makes use of it.
    • Deals with quantity and quality of food and the process of receiving and utilizing it for growth, renewal, and maintenance of body functions.
    • Involves using food for growth, metabolism, and repair; nourishing substances such as nutritional solutions delivered to hospitalized patients via IV/ID.
    • Basic function: maintain life and support growth and optimum health.

  • NUTRIENTS

    • Chemical nutrients present in food and delivered to the body.

  • FUNCTION OF NUTRITION

    • Provide energy.
    • Build and repair tissues.
    • Regulate body/life processes.

  • FIVE DIMENSIONS OF HEALTH

    • Physical, Intellectual, Emotional, Social, Spiritual health.

  • FOOD

    • Any substance, organic or inorganic, when ingested nourishes the body by building/repairing tissue, supplying heat and energy, and regulating body processes.
    • Basic human need along with clothing and shelter.

  • PROCESS OF DIGESTION

    • Digestión is the process of breaking down food into substances (carbohydrates, proteins, fats, vitamins) that aid body functions.

  • DIGESTIVE SYSTEM FUNCTIONS

    • Take in food.
    • Break down the food.
    • Absorb digested molecules.
    • Provide nutrients.
    • Eliminate wastes.

  • MOUTH (ORAL CAVITY)

    • First part of the digestive tract; lips and cheeks aid mastication (chewing).
    • Mastication = mechanical digestion; breaks large particles into smaller ones.

  • SALIVARY GLANDS & SALIVA

    • Saliva moistens the oral cavity and contains enzymes that begin chemical mastication.
    • Saliva produced at ~1 L/day.
    • Salivary amylase breaks down starch and other polysaccharides to maltose and isomaltose.

  • TONGUE

    • Large, muscular organ that moves food in the mouth; cooperates with lips and cheeks to hold food during mastication.
    • Major role in swallowing; sensory organ for taste; important for speech.

  • STOMACH

    • Enlarged segment of digestive tract in the left upper abdomen; storage and mixing chamber.
    • Food mixes with stomach secretions to form chyme.
    • Pepsinogen converted to pepsin by hydrochloric acid; pepsin cleaves proteins into smaller peptides.
    • Gastrin is a hormone that regulates stomach secretion.
    • Approximately 2~ ext{L} of gastric secretions produced daily.

  • SMALL INTESTINE

    • Major site of digestion and absorption due to large surface area.
    • Absorbs nutrients; most absorption occurs in the duodenum and jejunum; some in ileum.
    • Secretions from intestinal mucosa, liver, and pancreas contribute to digestion.
    • Peptidases break peptide bonds into amino acids.

  • LIVER AND PANCREAS

    • Liver: digestive/excretory functions; stores/processes nutrients; synthesizes molecules; detoxifies harmful chemicals.
    • Pancreas: has endocrine (islets producing insulin and glucagon) and exocrine (acinar) parts; secretes digestive enzymes; contains pancreatic amylases and lipase (lipid-digesting enzymes).

  • LARGE INTESTINE

    • Contains cecum, colon, rectum, anal canal.
    • Normally requires 18–24 hours for material to pass; chyme becomes feces in the colon.
    • Absorbs water and salts; mucus secretion; microorganisms synthesize vitamins (e.g., vitamin K) passively absorbed.

  • SELF-DIRECT LEARNING NO.1

    • Discuss and outline the composition of cells, biochemical structure/formula.

  • CHAPTER 2 MACRONUTRIENTS

  • MACRONUTRIENTS DEFINITION

    • Needed in large amounts: carbohydrates, proteins, fats.
    • Provide energy and building blocks for growth and tissue maintenance.

  • NOTE: ENERGY SOURCE PRIORITY

    • Carbohydrates are the body’s main energy source.
    • If carbohydrates are absent, fat is broken down for energy.
    • If both sources are insufficient, protein is used for energy.

  • CHO (CARBOHYDRATES)

    • Major role: energy production.
    • RDA: 130\,\text{g/day} for adults and children.
    • Excess CHO intake leads to obesity due to increased fat storage in adipose tissue.
    • Common carbohydrate sources: sugars, cereal grains and products (rice, corn, oats, bread, pasta), root crops, starchy vegetables, dried legumes; fruits and milk also contribute.

  • CLASSIFICATION OF CARBOHYDRATES

    • MONOSACCHARIDES
    • DISACCHARIDES
    • POLYSACCHARIDES

  • MONOSACCHARIDES

    • Fructose (fruit sugar): sweetest sugar; naturally in fruits/honey; hydrolyzed from sucrose; also called levulose.
    • Glucose (Dextrose): also called grape sugar; main energy source for cells; present in fruits, vegetables, corn syrup, honey; all other sugars are converted to glucose.
    • Galactose: not free in nature; hydrolyzed from lactose; component of cerebrosides in brain and nerves.

  • DISACCHARIDES

    • Sucrose (table sugar): from beets, sugar cane, corn; called cane/beet sugar; abundant in molasses, maple syrup, sorghum, some fruits; most common form of sugar in cooking.
    • Maltose (malt sugar): derived from digestion of starch with diastase; in intestines not readily fermented by bacteria (beneficial for infant feeding); often combined with dextrin (dextrin maltose) in infant formula.
    • Lactose (milk sugar): main sugar in milk; some people have lactose intolerance; hydrolyzed to glucose and galactose; least sweet among common sugars (about 1/6 as sweet as sucrose).

  • POLYSACCHARIDES

    • Not water-soluble compared to mono- and disaccharides.
    • STARCH: world's most abundant form; storage form in plants (grains, seeds, tubers, roots, unripe fruits).
    • DEXTRIN: intermediate product of starch digestion; formed from partial hydrolysis; heat processing (toasting bread, browning) produces dextrin.
    • GLYCOGEN: animal starch; storage form of carbohydrate in liver and muscles.

  • FUNCTION OF CARBOHYDRATES (KEY PROPERTIES)

    • Chief energy source.
    • Factors that lower blood sugar level; factors that raise blood sugar level; factors that maintain blood sugar level.
    • Cheap and main energy source; staple foods contribute at least half of total energy needs; low-cost and widely distributed.
    • Protein-sparer: fuels energy needs so proteins can be used for tissue building.
    • Regulator of fat metabolism: prevents incomplete oxidation of fat.
    • Brain and nerve tissue energy: brain/nerve tissues rely on glucose; constant glucose supply is essential.
    • Storage form of energy as glycogen.
    • Regulator of intestinal peristalsis and bulk via dietary fiber.

  • CARBOHYDRATE MALNUTRITION

    • Severe deficiencies lead to PEM (protein-energy malnutrition) and related issues.
    • Clinical signs: decreased blood sugar, weight loss, retarded growth in infants/children; obesity from excess calories; ketosis in low carbohydrate intake.

  • DIETARY FIBER (FIBER)

    • Provides bulk; regulates peristalsis; reduces constipation; may help prevent diverticular disease, colon cancer, reduce blood cholesterol, and decrease mucosal absorption.
    • Also called roughage; indigestible polysaccharides like cellulose.
    • CELLULOSE: polymer of glucose; major indigestible carbohydrate.
    • HEMICELLULOSE: indigestible polysaccharide with sugars other than glucose.
    • ECTIN/AGAR-AGAR: soluble fibers; thickening/binding agents; form gels; provide bulk in colon and laxative effect.
    • PSYLLIUM: soluble fiber from Plantago ovata seeds; ~80% dietary fiber; small amounts of protein, fat, vitamins, minerals.

  • SELF-ASSESSMENT EXERCISE NO.1

    • Multiple-choice questions to discuss composition of cells, biochemistry and structure/formula.

  • CHAPTER 2, LESSON 4: PROTEIN AND AMINO ACIDS

  • PROTEIN FUNCTIONS

    • Repair/build body tissues; drive metabolic reactions; maintain pH and fluid balance; immune function; transport/storage of nutrients; can serve as energy source.
    • Origin: Greek proteios meaning “to hold first place.”
    • SOURCES: Meat, poultry, fish, milk, wheat, corn, beans, nuts.
    • RDA: ext{Protein (g/day)} = ext{Weight (kg)} \times 0.8
    • Ranges: Normal adults ~0.8\,\g/day\text{ per kg}; athletes ~1.0; pregnancy/lactation up to 30; children ~2.0.
    • Note: Protein provides amino acids; nitrogen source in the body; protein is the only nitrogen source.

  • AMINO ACIDS

    • Building blocks of proteins; 22 amino acids; each distinguished by R-group attached to alpha carbon (CHON elements).
    • Essential (PVT TIM HALL): Phenylalanine, Valine, Tryptophan, Threonine, Isoleucine, Methionine, Histidine, Arginine, Lysine, Leucine.
    • Non-essential: can be synthesized by the body; examples include glutamic acid, aspartic acid, alanine, proline, norleucine, citrulline, hydroxyglycine, hydroxyproline.
    • Excess amino acids can be oxidized for energy or converted to acetyl-CoA for fat synthesis; excess protein may be stored as fat.

  • SPECIFIC AMINO ACID ROLES

    • Methionine: methylating agent; helps form heme of red blood cells; helps form choline.
    • Phenylalanine: precursor to tyrosine; key for thyroxine and epinephrine.
    • Tryptophan: precursor to niacin (vitamin B3).
    • Thyroxine (T4): metabolism; Epinephrine: adrenal hormone; neurotransmitter.
    • Niacin (nicotinic acid) derived from tryptophan.
    • Glycine: detoxification via conjugation of toxins.
    • Leucine/Isoleucine/Valine: participate in alanine–glucose cycle; nitrogen release.

  • WAYS TO IMPROVE PROTEIN QUALITY

    • Fortification: add amino acids to increase desirable levels (e.g., lysine to bread).
    • Enrichment: restore what was lost during milling (e.g., lysine to cereals).
    • Supplementation: add protein-rich foods to diet.
    • Complementation: combine foods to balance essential amino acids (e.g., rice + munggo; soybean + wheat; soybean + nuts; soybean + corn; soybean + red kidney bean).

  • PROTEIN TYPES

    • Fibrous proteins: protective tissues (skin, hair, tendons, feathers, fins/scales).
    • Examples: Keratin, Collagen, Fibrin, Myosin, Elastin.
    • Globular proteins: soluble in water; examples: Casein (milk), Albumin (egg whites), Globulin (blood).

  • AMINO ACID CONTENT OF PROTEINS

    • Complete proteins: contain all essential amino acids in sufficient amounts; usually animal proteins; high biological value (e.g., casein, egg albumin).
    • Partially complete proteins: support life but not growth (e.g., gliadin in wheat, legumin in legumes).
    • Incomplete proteins: cannot support life/growth (e.g., zein in corn; gelatin; many plant proteins).

  • PROTEIN-ENERGY MALNUTRITION (PEM)

    • PEM/CPM results from insufficient total energy and/or protein intake.
    • Signs: general weakness, weight loss, reduced infection resistance, lethargy; edema and dry skin in advanced stages; growth retardation in children; hepatomegaly.
    • Forms: Marasmus (severe energy and protein deficiency; no edema; emaciation) vs Kwashiorkor (protein deficiency with edema; liver fat accumulation; higher mortality).
    • Distinguishing features: TSF/MAC decreased in marasmus; edema present in kwashiorkor; visceral protein levels altered in kwashiorkor; hair/clital changes differ.

  • CRITICAL THINKING PROMPTS (PROTEIN)

    • Discuss at least 2 protein-related diseases (signs, causes, dietary changes).
    • Explain health effects of protein (approx. 100 words).
    • Differentiate acute PEM from chronic PEM (approx. 100 words).

  • LESSON 5: FATS AND OTHER LIPIDS

  • ENERGY & FATS

    • Concentrated energy: 9 kcal/gram for all fats.
    • RDA: total fats ~65\,\text{g/day}; saturated fats ~20\,\text{g/day}.

  • IMPORTANCE OF FATS

    • Provide essential fatty acids (linoleic, linolenic).
    • Provide phospholipids for membranes.
    • Source of fat-soluble vitamins (A, D, E, K) and aid in their absorption.

  • ESSENTIAL VS NON-ESSENTIAL FATTY ACIDS

    • Essential fatty acids (EFAs): must be obtained from diet; long-chain polyunsaturated fatty acids from linoleic, linolenic, and oleic acids; two families: Omega-3 and Omega-6.
    • Nonessential (Omega-9): body can synthesize in adequate amounts if EFAs present.

  • CHEMICAL STRUCTURE & CLASSIFICATION

    • Fats: carbon, hydrogen, oxygen; glyceride linkage; less oxygen than carbohydrates.
    • In food, fats are solid at room temperature; oils are liquid.
    • Lipids classified by molecular complexity: simple (neutral fats, triglycerides), compound, and derived lipids.
    • Visible fats: butter, margarine, lard, cooking oils; invisible fats: fats in foods like egg yolk, milk, olives, avocado, marbled meats.

  • TRIGLYCERIDES (SIMPLE LIPID)

    • Made of three fatty acids attached to glycerol; most lipids in the body are triglycerides (~95%).
    • Circulate in blood; stored in adipose tissue.

  • COMPOUND LIPIDS

    • Phospholipids (e.g., lecithins, cephalins, sphingomyelins) with fatty acids, phosphoric acid, and nitrogenous bases.
    • Glycolipids (cerebrosides, gangliosides) with carbohydrate components and nitrogenous bases; important in nerve tissue and cell membranes.

  • LIPOPROTEINS

    • Lipids combined with proteins; formed mainly in liver; transport fats in blood.
    • Absorption: bile emulsifies fats; pancreatic lipase digests fats; lipoproteins carry fats to body cells.
    • Chylomicrons: largest, lightest; 80–90% triglycerides; lipoprotein lipase acts to release fatty acids and glycerol.
    • VLDLs (Very-Low-Density Lipoproteins): 55–65% triglycerides; release TGs and pick up cholesterol to become LDLs.
    • LDLs (Low-Density Lipoproteins): ~45% cholesterol; carry most blood cholesterol to cells; elevated LDL > 130 mg/dL linked to atherosclerosis; “bad cholesterol.”
    • HDLs (High-Density Lipoproteins): carry cholesterol from cells to liver for excretion; HDL ≥ 60 mg/dL considered protective; “good cholesterol.”

  • CHOLESTEROL & STEROLS

    • Not a true fat but a fat-like substance; present in animal foods; not found in plants.
    • Essential for bile acids, steroid hormones, vitamin D; produced endogenously in liver (≈800–1000 mg/day).
    • Dietary cholesterol intake recommended not to exceed 300 mg/day.
    • Hypercholesterolemia increases risk for heart disease; atherosclerosis involves arterial plaque formation.
    • Sources: egg yolk, fatty meats, shellfish, organ meats; also in dairy fat.

  • DIGESTION & ABSORPTION OF FATS

    • ~95% of ingested fats are digested; digestion mainly in the small intestine.
    • Mouth: fats not digested; stomach: gastric lipase provides limited digestion on emulsified fats (creams, egg yolk).
    • Emulsification by bile in the small intestine; pancreatic lipase converts fats to fatty acids and glycerol; absorbed by villi.
    • Unsaturated fats can be converted to trans fats (TFAs) via hydrogenation, forming semisolid fats (margarine/shortening).
    • TFAs raise LDL and total cholesterol.

  • LIPOPROTEIN CLASSIFICATIONS & RISK FACTORS

    • Chylomicrons, VLDLs, LDLs, HDLs roles summarized above; altering dietary fat affects lipoprotein profiles and cardiovascular risk.

  • OMEGA-3 & OMEGA-6 FATS

    • Omega-3: found in fish oils; reduce triglycerides; may reduce platelet aggregation; may lower blood pressure in some individuals.
    • Omega-6 (Linoleic acid): found in vegetable oils; can lower cholesterol; intake should be balanced; limit saturated fats and trans fats.
    • Recommendations: Omega-3/omega-6 intake varies; avoid excessive saturated fats; guidelines suggest replacing saturated fats with unsaturated fats.

  • FATS: ADDITIONAL FUNCTIONS

    • Fat provides satiety and flavor; some lipids act as emulsifying agents (lecithin) to aid transport across membranes.
    • Prostaglandins derived from fatty acids participate in regulation of blood pressure, heart rate, and lipolysis.
    • Fats help maintain moisture in foods.

  • DEFICIENCY & EXCESS OF FATS

    • Deficiency reduces caloric intake and may cause protein catabolism; essential fatty acid deficiency causes retarded growth and dermatitis.
    • Excess fat intake (>normal levels, typically 20–30% of total energy) leads to obesity.

  • FOOD SOURCES OF FATS

    • Visible fats and oils (butter, margarine, lard, cooking oils, fish liver oils, etc.).
    • Good sources: nuts, oilseeds, fatty fish, eggs, dairy, avocados, olives, chocolate.
    • Plant oils: corn, cottonseed, sesame, sunflower, olive, soy; coconut oil is high in saturated fats.

  • DIETARY GUIDELINES & LIMITS

    • In the Philippines, at least 20% of total calories from fat; higher for children/active adults.
    • Saturated fat: men ≤ 30 g/day; women ≤ 20 g/day; children lower.
    • Trans fats: limit to ≤ 5 g/day; avoid partially hydrogenated oils. Replacements with unsaturated fats reduce risk.
    • Total fat should be balanced with carbohydrate and protein intake to meet energy needs.

  • OTHERS: SODIUM, SODIUM & SALT GUIDELINES (RELEVANT TO LIPID CONTEXT)

    • Lowering sodium intake: recommended to limit processed foods; read labels; rinse canned vegetables; use spices instead of salt; typical general advice is ~6 g salt per day.

  • CHLORINE & SULFUR

    • Chlorine (Cl) helps with fluid and electrolyte balance; part of HCl in stomach.
    • Sulfur contributes to disulfide bonds in proteins; activates enzymes; detoxification roles; present in ~1% of dietary protein.

  • TRACE MINERALS (IRON, IODINE, ZINC, FLUORIDE)

    • IRON: essential for oxygen transport via hemoglobin; two forms: heme (animal) and non-heme (plants); absorption aided by vitamin C when paired with meat; RDA: women 18 mg/day (19–50 years); men 8 mg/day (19+).
    • IODINE: required for thyroid hormone synthesis (T3, T4); goiter/cretinism from deficiency; iodized salt main source; recommended intakes by age: infants 110–130 µg/day; children 90–120 µg/day; adolescents/adults 150 µg/day; pregnancy 220 µg/day; lactation 290 µg/day.
    • ZINC: essential trace element; supports vision and antiviral activity; sources include red meat, poultry, fish.
    • FLUORIDE (FLOURINE): essential trace element; chronic excess causes fluorosis; dental/bone changes.

  • ADDITIONAL TRACE NUTRIENTS & NOTES

    • CHOLINE: essential nutrient; involved in acetylcholine synthesis and lecithin; AI: 550 mg/day for men, 425 mg/day for women; UL 3500 mg/day; deficiency is rare; toxicity possible with high intake (sweating, fishy odor, liver damage).
    • INOSITOL: linked with phospholipids and phosphoinositol; aids fat transport/metabolism; sometimes called "muscle sugar" due to similarity to glucose.

  • VITAMINS (CHAPTER 3 SUMMARY)

  • VITAMINS OVERVIEW

    • Organic compounds required in small amounts for biochemical processes; mostly coenzymes; essential; non-caloric; not energy providing; soluble in fat or water.
    • Fat-soluble vitamins: A, D, E, K; stored in body.
    • Water-soluble vitamins: B-complex (B1, B2, B3, B6, B12), C; not stored to the same extent as fatsoluble vitamins.

  • VITAMIN A (RETINOL)

    • Forms: Preformed vitamin A (retinol) and Provitamin A (carotenoids: beta-carotene, lutein, lycopene, zeaxanthin).
    • Functions: vision, bone growth, reproduction, cell division; immune support; antioxidant.
    • Sources: retinol from animal foods (liver, butter, cream, whole milk products, egg yolk); provitamin A from colorful fruits/vegetables (carotenes).
    • Retinol equivalents (RE): 1 µg retinol = 6 µg beta-carotene.
    • Deficiency: night blindness, xerophthalmia; hypervitaminosis A can cause birth defects, hair loss, dry skin, liver damage, bone pain.

  • VITAMIN D

    • Forms: D2 (ergocalciferol) and D3 (cholecalciferol); synthesized in skin via ultraviolet light exposure; considered a prohormone.
    • Functions: promotes calcium and phosphorus absorption; supports bone/mineralization; prevents tetany.
    • Sources: sunlight; dietary sources include fortified milk, fish, liver oils, egg yolk, butter, fortified margarine.
    • Dietary requirements (AI): ≈5 µg/day; age-based increases (2 cups vitamin D–fortified fat-free milk/day adequate up to age 50; 51–70 years ~10 µg/day; >70 years ~15 µg/day).
    • Hypervitaminosis D can cause ectopic calcium deposition and bone issues.
    • Deficiencies: rickets in children; osteomalacia in adults; osteoporosis risk.

  • VITAMIN E

    • Forms: tocopherols (alpha, beta, gamma, delta); alpha-tocopherol most active.
    • Functions: antioxidant; supports immune function; prevents hemolytic anemia in premature infants.
    • Sources: vegetable oils (corn, soybean, safflower, cottonseed), margarine; nuts, seeds, leafy greens; wheat germ.
    • AI: 15 mg alpha-tocopherol equivalents (ATE) for adults.
    • Deficiency: hemorrhagic disease in newborns; delayed blood clotting in adults; fat malabsorption issues.

  • VITAMIN K

    • Forms: K1 (phylloquinone) from green leafy vegetables; K2 (menaquinone) synthesized by intestinal bacteria; synthetic form is menadione.
    • Functions: essential for prothrombin formation; clotting; antidote for excessive anticoagulant use; treats hemorrhage.
    • Sources: leafy greens (broccoli, cabbage, spinach, kale); dairy, eggs, meats, cereals.
    • Dietary requirements: men ≈120 µg/day; women ≈90 µg/day; infants 2.0 µg (0–6 months) and 2.5 µg (6–12 months).
    • Hypervitaminosis K is rare but possible; deficiency leads to defective blood coagulation.

  • WATER-SOLUBLE VITAMINS & B-COMPLEX

    • Overview: dissolve in water; not stored extensively; include B1, B2, B3, B6, B12, C, and others (biotin, pantothenic acid, folate, etc.).

  • VITAMIN B1 (THIAMINE)

    • Role: coenzyme in carbohydrate metabolism; essential for nervous system/muscle function.
    • Sources: cereals (unrefined/enriched), legumes, yeast, wheat germ, lean pork, organ meats.
    • Requirements: measured in mg; women ~1.1 mg/day; men ~1.2 mg/day.
    • Deficiency: Beriberi (dry: nervous system, muscle wasting; wet: edema and heart involvement); Wernicke-Korsakoff syndrome (chronic alcohol use).

  • VITAMIN B2 (RIBOFLAVIN)

    • Role: coenzyme in energy metabolism; essential for energy release; skin/eye health.
    • Sources: plant/animal foods (broccoli, greens, whole grains, enriched breads/cereals; dairy, meats, fish, eggs).
    • Deficiency: Ariboflavinosis; cheilosis; glossitis; seborrheic dermatitis.

  • VITAMIN B3 (NIACIN)

    • Forms: Nicotinic acid and Niacinamide; coenzyme in energy metabolism; essential for glycolysis and TCA cycle.
    • Sources: protein-rich foods, meats, poultry, fish, legumes, enriched cereals, milk, eggs; niacin equivalents (NE) reflect tryptophan to niacin conversion: 1 NE = 1 mg niacin or 60 mg tryptophan.
    • Daily recommendations: women ~14 mg NE/day; men ~16 mg NE/day; UL ~35 mg NE/day.
    • Deficiency: Pellagra (3 D’s: dermatitis, diarrhea, dementia); symptoms include GI/mouth changes, dermatitis, and CNS effects.

  • VITAMIN B6 (Pyridoxine)

    • Forms: Pyridoxine, Pyridoxal, Pyridoxamine; all convert to PLP (pyridoxal phosphate).
    • Functions: PLP-dependent amino acid and protein metabolism; neurotransmitter synthesis; hemoglobin synthesis; conversion of tryptophan to niacin; fatty acid and carbohydrate metabolism.
    • Sources: animal (poultry, fish, liver, meat, eggs); plant (spinach, oats, potatoes, bananas).
    • Requirements: mg/day; women ~1.3–1.5 mg; men ~1.3–1.7 mg.
    • Deficiency: often coexists with other B-vitamin deficiencies; symptoms include irritability, dermatitis, altered nerve function; convulsions; microcytic anemia. Toxicity mainly in animals; human toxicity rare.

  • VITAMIN B5 (PANTOTHENIC ACID)

    • Role: essential in carbohydrate, protein, and fat metabolism; part of coenzyme A; supports growth and skin health; important in CNS.
    • Deficiency: not known in humans; toxicity: not well established; typical intake around 5 mg/day is sufficient.
    • Sources: liver, meat, eggs, milk, cheese, legumes.

  • LIPOIC ACID

    • Not a true vitamin; can be synthesized in the body; sources include yeast and liver.

  • VITAMIN H (BIOTIN)

    • Role: coenzyme in fatty acid and amino acid synthesis; synthesized by gut bacteria; supports energy production; health of hair, skin, nails.
    • AI: 30 µg/day.
    • Deficiency: nausea, anorexia, dermatitis, hair loss; sources include liver, egg yolk, peanut butter, soy flour, cereals, yeast.

  • FOLATE (FOLACIN, FOLIC ACID)

    • Role: DNA synthesis; amino acid metabolism; heme synthesis in hemoglobin.
    • Sources: fortified cereals, sunflower seeds, green leafy vegetables, fruits (orange, strawberries), legumes.
    • Requirements: micrograms (µg); adult female 400 µg/day; male 400 µg/day; increased during pregnancy (600 µg/day first 6 weeks).
    • Deficiency: neural tube defects (NTD) like spina bifida and anencephaly; megaloblastic anemia; glossitis; GI disturbances; impaired absorption.

  • VITAMIN B12 (COBALAMIN)

    • Contains cobalt; forms include cyanocobalamin.
    • Functions: folate metabolism; maintenance of myelin sheath; healthy red blood cells; supports GI tract, bone marrow, nervous tissue.
    • Absorption: requires intrinsic factor from stomach secretions; complex absorption involving pancreatic proteases and ileal receptors; pernicious anemia results from lack of intrinsic factor.
    • Sources: animal foods (organ meats, lean meats, seafood, eggs, dairy).
    • Requirements: micrograms; adult DRI ~2–4 µg/day; higher during pregnancy/lactation.
    • Deficiency: usually secondary; megaloblastic anemia; neuropathy; glossitis; weight loss.

  • CHOLINE & INOSITOL

    • CHOLINE: essential nutrient, precursor to acetylcholine and lecithin; AI: 550 mg/day (men) and 425 mg/day (women); UL 3500 mg/day; deficiency rare; toxicity can cause sweating, fishy odor, liver damage.
    • Sources: milk, eggs, peanuts.
    • DEFICIENCY: rare.
    • INOSITOL: linked to phospholipids and phosphatidylinositol; supports fat transport/metabolism; sometimes called 'muscle sugar' due to similarity to glucose.

  • VITAMIN C (ASCORBIC ACID)

    • Water-soluble; antioxidant and coenzyme; prevents scurvy; essential for collagen formation; aids non-heme iron absorption; supports immune function and potentially cancer risk reduction via nitrite interactions.
    • Sources: fruits and vegetables (citrus fruits, melons, strawberries, tomatoes, potatoes, peppers, cabbage, broccoli, leafy greens).
    • AI: women 75 mg/day; men 90 mg/day.
    • Deficiency: Scurvy (gum bleeding, loose teeth, joint/muscle pains, poor wound healing);
    • Toxicity: no known toxicity; body cannot store excess vitamin C.

  • VITAMINS: KEY TAKEAWAYS & PATHWAYS

    • Vitamins are micronutrients essential for metabolism, growth, and health; many act as coenzymes in energy production and other cellular processes.
    • Adequate diet with diverse foods generally meets vitamin needs; supplementation may be necessary in certain populations or for specific deficiencies.

  • CHAPTER 3 MINERALS

  • MINERALS OVERVIEW

    • Micronutrients; do not provide calories; not destroyed by heat in general; ash remaining after burning food represents mineral content.
    • Minerals regulate numerous bodily processes, including water balance, heartbeat, nerve response, wound healing, enzyme function, and energy release.

  • TYPES OF MINERALS

    • MAJOR MINERALS: calcium, phosphorus, potassium, magnesium, sodium, chloride, sulfur.
    • TRACE MINERALS: iron, iodine, fluoride, zinc, manganese, chromium, molybdenum, copper, selenium.

  • FUNCTIONS & GENERAL NOTES

    • Build teeth/bones; regulate body processes; essential parts of body fluids and cells; part of enzymes and proteins involved in energy release.

  • MAJOR MINERALS: CALCIUM

    • Distribution: 1.5–2.2% of body weight; 99% in bones/teeth; ~1% in soft tissues and body fluids.
    • Functions: combines with phosphorus to form calcium phosphate in bones/teeth; blood clotting; muscle contraction/relaxation; promotes circulation.
    • Sources: dairy, fortified white bread, oily fish, green vegetables, nuts/seeds, citrus.
    • Deficiency/Excess effects: stunted growth/rickets; osteomalacia; hypercalcemia.

  • PHOSPHORUS

    • Distribution: ~1% of body weight; 85% in inorganic phase of bones/teeth with calcium.
    • Functions: calcified bones/teeth; component of every cell; participates in muscle contraction.
    • Sources: milk/dairy; fortified foods; fish with edible bones; tofu; fortified foods; plant sources vary.
    • Notes on deficiency and balance with calcium; risk groups for calcium deficiency include children, women/postmenopausal women, strict vegetarians.

  • POTASSIUM

    • Distribution: principal intracellular cation; ~2.6 g/kg fat-free weight; ~0.35% of body weight.
    • Functions: maintains fluid/electrolyte balance; skeletal and cardiac muscle activity; carbohydrate and protein metabolism.
    • Sources: meat, legumes, milk, raw/dried fruits, fruit juices, leafy greens, unrefined cereals.
    • Deficiency/excess: hypokalemia (wasting diseases); hyperkalemia (kidney failure); symptoms include weakness, confusion, abdominal distention.

  • MAGNESIUM

    • Distribution: ~50% in bones; ~1% in extracellular fluid; rest interiorly.
    • Functions: supports energy production, protein synthesis, muscle/nerve function, blood glucose control, blood pressure regulation; helps transport calcium/potassium.
    • Sources: nuts, soybeans, meat, milk, cocoa, seafood, whole grains, dried beans/peas, leafy greens.
    • Deficiency: hypomagnesemia can occur in kwashiorkor, malabsorption, diarrhea, vomiting, alcoholism.

  • SODIUM & CHLORIDE

    • SODIUM: major extracellular cation; electrolyte; fluid balance; acid-base balance; enables glucose transport across cell membranes; muscle excitability.
    • Sources: table salt and various foods.
    • Chlorine (as chloride): maintains fluid/electrolyte balance; contributes to gastric acidity (HCl).
    • Fluorine/Fluoride: dental and bone changes with chronic excess (fluorosis).

  • SULFUR

    • Functions: maintains protein structure via disulfide bonds; activates enzymes; participates in detoxification; present in ~1% of protein-containing diet.
    • Deficiency: rare; certain genetic issues can cause cystinuria.

  • TRACE MINERALS: IRON

    • Iron is essential for oxygen transport (hemoglobin) and cellular respiration (cytochromes).
    • Forms in foods: Heme iron (animal products) more readily absorbed; Non-heme iron (plants) absorption aided by vitamin C; co-ingestion with meat improves absorption of non-heme iron.
    • Food sources: fish, dried beans, meat, liver, poultry, eggs, leafy greens, fortified cereals.
    • RDAs: women 18 mg/day (19–50); men 8 mg/day (19+).
    • Iron overload risk and poisoning potential from supplements.
    • Tips to increase iron intake: vitamin C with meals; cook in iron pots; include meat; avoid inhibitors like caffeine, spinach (excess), chocolate, fiber, antacids, calcium supplements around meals.

  • IODINE

    • Function: synthesis of thyroid hormones (T3, T4) influencing many metabolic functions.
    • Sources: iodized salt, seafood, kelp, dairy; plants grown in iodine-rich soil.
    • Deficiency effects by group: Goiter; cretinism in pregnancy; impaired cognitive development in children; goiter/thyroid effects in adults.
    • Toxicity: goiter due to hormone suppression.
    • Recommended daily intakes by age: infants 110–130 µg; children 90–120 µg; adolescents/adults 150 µg; pregnant 220 µg; lactating 290 µg.

  • ZINC

    • Essential trace element; role in vision and antiviral activity; potential effects against rhinovirus; sources include red meat, poultry, fish.
    • Deficiency signs: growth retardation, reduced appetite, impaired immune function; hair loss; diarrhea; delayed sexual maturation; skin/eye lesions; weight loss; taste impairment.

  • OTHERS: FLUORIDE

    • Essential trace element; chronic excess causes dental/bony changes (fluorosis).

  • DIETARY PRACTICAL NOTES

    • Balance: meet micronutrient needs via a varied diet including dairy, lean meats, fortified products, leafy greens, whole grains, and fortified cereals.
    • Consider interactions: vitamin C enhances non-heme iron absorption; fat-soluble vitamins require dietary fats for absorption; certain foods enhance or inhibit mineral uptake.

  • CLOSING REMARKS

    • The material emphasizes the interconnectedness of carbohydrates, proteins, fats, vitamins, and minerals with energy metabolism, tissue maintenance, and overall health.
    • It also highlights the role of dietary patterns in disease risk (e.g., cardiovascular disease, PEM, deficiency disorders) and the importance of balanced intake across macronutrients and micronutrients.

  • NOTE ON EQUATIONS & NUMBERS USED

    • Protein requirement: ext{Protein (g/day)} = ext{Weight (kg)} \times 0.8
    • Carbohydrate RDA: 130\,\text{g/day}
    • Fat energy: 9\ \text{kcal/g}
    • Cholesterol daily limit: < 300\ \text{mg/day}
    • LDL threshold for risk: ext{LDL} > 130\ \text{mg/dL} \Rightarrow \text{increased risk}
    • Vitamin A: Retinol Equivalents (RE): 1\,\mu g\text{ retinol} = 6\,\mu g\beta\text{-carotene}
    • Vitamin D AI: ext{AI} \approx 5\ \mu\text{g/day} (varies by age)
    • Vitamin E AI: 15\ \text{mg}\ \text{alpha-TE}
    • Vitamin C AI: 75\ \text{mg/day (women)},\ 90\ \text{mg/day (men)}
    • Iodine: group-specific DRIs as listed above in µg/day.

  • SELF-REVIEW PROMPTS

    • Explain the role of dietary fats in energy provision, cell function, and vitamin absorption.
    • Distinguish between saturated, unsaturated, and trans fats with health implications.
    • Compare marasmus and kwashiorkor in PEM, including signs, causes, and dietary changes.
    • Describe how carbohydrates influence fat metabolism and brain energy.