NTRI 2000 Exam 3 Study Guide: Vitamins, Water & Minerals, Energy Balance

Comprehensive vocabulary flashcards covering the key terms, nutritional mechanisms, deficiency states, and metabolic definitions from Chapters 7, 8, and 9 for the NTRI 2000 Exam 3.

Vitamin

An organic compound essential for normal body functions, needed in small amounts, that provides no energy or calories.

Coenzyme

A helper molecule, often derived from vitamins, that assists enzymes in carrying out biochemical reactions.

Precursor (Provitamin)

A substance found in food that the human body can convert into an active vitamin, such as plant beta-carotene converting to vitamin A.

Fat-Soluble Vitamins

Vitamins A, D, E, and K, which are absorbed with dietary fat into the lymph, require protein carriers in blood, are stored in the liver and fatty tissues, excreted slowly, and carry a greater risk of toxicity from supplements.

Water-Soluble Vitamins

Vitamin C and the eight B vitamins, which are absorbed directly into the bloodstream, travel freely in watery fluids, have minimal tissue storage, and are readily excreted in urine.

Retinol, Retinal, and Retinoic Acid

The three active forms of vitamin A responsible for liver storage, vision, and gene expression/cell growth, respectively.

Carotenemia

A harmless yellow-orange discoloration of the skin caused by high intake of the plant precursor beta-carotene.

Xerophthalmia

Progressive eye damage and irreversible blindness caused by severe vitamin A deficiency, characterized by dry eyes (xerosis), Bitot's spots, and corneal damage.

Rickets

A deficiency disease in children caused by inadequate vitamin D, leading to improper bone mineralization and weak bones.

Osteomalacia

The adult form of vitamin D deficiency characterized by a softening of the bones and reduced bone density.

Alpha-Tocopherol

The DRI form of vitamin E that functions as an antioxidant protecting cell membranes from free-radical damage.

Vitamin K

A fat-soluble nutrient available as $K_1$ from plants, $K_2$ from bacterial synthesis/fermented foods, and synthetic $K_3$; it is required for blood clotting and activating bone proteins.

Scurvy

The deficiency disease of vitamin C marked by collagen breakdown, bleeding gums, loose teeth, petechiae, poor wound healing, weakness, and anemia.

Petechiae

Pinpoint skin hemorrhages caused by capillary fragility and collagen breakdown in vitamin C deficiency.

Beriberi

The deficiency disease of thiamin (vitamin B1); manifests as dry beriberi (muscle wasting, weakness, nerve damage) or wet beriberi (edema, enlarged heart, and heart failure).

Wernicke-Korsakoff Syndrome

A severe neurological disorder linked to alcohol use disorder and thiamin (vitamin B1) deficiency, presenting with confusion, memory loss, poor coordination, and abnormal eye movements.

Ariboflavinosis

The deficiency disease of riboflavin (vitamin B2) characterized by cracks/redness at the corners of the mouth (cheilosis), a smooth magenta tongue, sore throat, and light-sensitive eyes.

Pellagra

The deficiency disease of niacin (vitamin B3) defined by the "4 Ds": dermatitis, diarrhea, dementia, and death.

Niacin Flush

A temporary condition of skin redness, tingling, and itching/rash resulting from high-dose supplements of niacin (UL $35\text{ mg/day}$ for adults).

Neural Tube Defects

Severe congenital abnormalities of the brain and spinal cord that are reduced by maternal folate (vitamin B9) intake and enriched grain fortification.

Intrinsic Factor

A stomach-secreted protein compound strictly required for the intestinal absorption of vitamin B12 (cobalamin).

Pernicious Anemia

A form of megaloblastic anemia caused by a lack of intrinsic factor leading to vitamin B12 malabsorption and progressive neurological damage.

Choline

A conditionally essential nutrient needed for cell-membrane structure, lipid metabolism, acetylcholine synthesis, and fetal brain/spinal-cord development.

Water Balance

The balance in the body where water intake equals water output, primarily regulated by the hypothalamus/brain and the kidneys.

Hyponatremia

A dangerous dilution of blood sodium concentration resulting from water intoxication when water intake vastly exceeds output.

Mild Dehydration

A loss of body water under $5\%$ of total body weight, marked by thirst, sudden weight loss, dry mouth/skin, rapid pulse, low blood pressure, headache, and concentrated urine.

Severe Dehydration

A loss of body water exceeding $5\%$ of total body weight, causing disorientation, bluish lips/fingertips, rapid shallow breathing, weak/irregular pulse, shock, seizures, or coma.

Electrolytes

Mineral ions in body fluids that conduct electric currents and determine fluid distribution through osmotic pressure.

Sodium-Potassium Pump

A cell-membrane protein pump that actively moves sodium outside and potassium inside cells to maintain fluid compartments and electrical impulses.

Acid-Base Balance

The physiological mechanism utilizing chemical buffers, the lungs, and the kidneys to hold body-fluid pH strictly between $7.34\text{--}7.45$.

Hydroxyapatite

The chief crystal structure composed of calcium and phosphorus that forms the mineral matrix of bones and teeth ($99\%$ of body calcium).

Peak Bone Mass

The maximum bone density reached in life, which occurs in the late 20s to early 30s.

Osteopenia

A condition characterized by a lower-than-normal bone mineral density that precedes osteoporosis.

Osteoporosis

A disease marked by porous, fragile, and low-density bones that develop silently over decades, increasing fracture susceptibility.

Chronic Disease Risk Reduction (CDRR) for Sodium

An established threshold of $2{,}300\text{ mg/day}$ of sodium (equivalent to approximately $1\text{ tsp}$ of table salt) set to decrease chronic illness risks.

Hypokalemia

Abnormally low blood potassium concentration, typically provoked by dehydration, vomiting, diarrhea, or diuretics, presenting with muscle weakness, cramps, and arrhythmias.

Hyperkalemia

Abnormally high blood potassium levels, frequently caused by kidney failure or salt substitutes/supplements, which can induce fatal cardiac arrest.

Heme Iron

The form of iron bound to hemoglobin and myoglobin in animal flesh that is absorbed much more readily than nonheme plant iron.

Nonheme Iron

The form of iron derived from plant foods and animal tissues whose absorption is increased by vitamin C and MFP factor, and decreased by phytates, tannins, and calcium.

Ferritin

The iron storage protein that keeps iron safely sequestered in tissues such as the liver.

Transferrin

The primary transport protein in the blood responsible for moving iron to bone marrow and body tissues.

Hepcidin

A liver-produced regulatory hormone that decreases intestinal iron absorption when iron stores are high or systemic inflammation is present.

Goiter

An abnormal enlargement of the thyroid gland caused by iodine deficiency or excess.

Cretinism

Severe congenital physical and mental retardation in an infant caused by maternal iodine deficiency during pregnancy.

Fluorosis

A condition characterized by permanent white mottling, brown stains, or pitting of the teeth resulting from chronic excess fluoride during development.

Adipokines

Hormones and signaling proteins secreted by adipose tissue that regulate appetite, energy metabolism, inflammation, and insulin action.

Visceral Fat

Adipose tissue stored intra-abdominally around vital organs; closely associated with central obesity, chronic inflammation, and metabolic disease.

Subcutaneous Fat

Adipose tissue located immediately underneath the skin, carrying a lower metabolic risk than central visceral fat.

Body Mass Index (BMI)

A screening metric calculated as $\frac{\text{weight (kg)}}{[\text{height (m)}]^2}$ correlating height and weight with general health risks.

Basal Metabolism (BMR)

The energy expended by the body to sustain involuntary, life-supporting basal processes at rest, primarily driven by lean body mass.

Thermic Effect of Food (TEF)

The metabolic energy expended by the body to digest, absorb, transport, and metabolize nutrients from consumed foods.

Hunger

The physiological drive to eat initiated by an empty digestive tract, mediated by signals from the stomach and hypothalamus.

Appetite

The psychological desire to consume food, which can occur independently of physical hunger and is guided by sensory, emotional, and environmental cues.

Satiation

The perception of fullness that develops during an eating occasion, prompted by stomach distension and gut hormones, which halts the meal.

Satiety

The post-meal feeling of fullness that persists over hours, actively suppressing appetite and delaying the next eating occasion.

Ghrelin

A hormone produced by the stomach that stimulates the hypothalamus to trigger the sensation of hunger.

Leptin

An adipokine hormone produced by fat cells that signals the brain to suppress appetite and maintain stable long-term body fat.

Set-Point Theory

The concept that internal regulatory mechanisms actively defend a specific, predetermined biological body fat and weight level.

Brown Adipose Tissue (BAT)

A specialized form of fat cell containing iron-rich mitochondria that expends energy directly as heat via thermogenesis; more prominent in infants.

Ketosis

An adaptive metabolic state during prolonged fasting or carbohydrate deprivation where the liver produces ketone bodies from fat to fuel the brain and nerves.