Vitamins, Minerals, and Fluid Homeostasis Overview

Vocabulary practice flashcards covering micronutrients, bone and blood health, electrolytes, hydration, and nutritional deficiency and toxicity conditions.

Vitamin

An organic compound naturally occurring in food that regulates physiological processes, cannot be synthesized by the body in sufficient amounts for good health, and whose absence results in a specific deficiency disease that is reversed when resupplied.

Fat-Soluble Vitamins

A class of vitamins comprising vitamins A, D, E, and K that are absorbed alongside dietary lipids, packaged into chylomicrons, and stored in the liver and adipose tissue, making toxic accumulation more likely than with water-soluble vitamins.

Water-Soluble Vitamins

A class of vitamins comprising the B-complex group and vitamin C that dissolve in water, function predominantly as metabolic coenzymes or cellular antioxidants, and are generally not stored in large amounts in body tissues.

Coenzyme

A small organic molecule, frequently derived from a B vitamin, that binds to an inactive apoenzyme to create an active holoenzyme capable of catalyzing biochemical reactions.

Bioavailability

The proportion of an ingested nutrient that is successfully digested, absorbed, and made physiologically accessible to tissues; it is influenced by gastrointestinal transit time, lipid absorption rates, food preparation methods, and nutritional sources.

Enrichment

The mandated replacement of specific micronutrients—specifically thiamin, riboflavin, niacin, folate, and iron—lost during the industrial milling and refining of grain products.

Fortification

The practice of deliberately adding essential vitamins or minerals to foods or beverages that were not naturally present or existed in lower quantities, such as adding vitamins A and D to cow's milk.

Free Radical

An unstable, highly reactive atomic or molecular species possessing an unpaired valence electron formed through oxidative reactions, capable of damaging cellular DNA, membrane phospholipids, and structural proteins.

Antioxidant

A molecule that donates electrons to neutralize unstable free radicals, halting oxidative chain reactions and preserving cellular stability without converting into a destructive radical itself.

Retinoids

The family of preformed vitamin A compounds (such as retinol) found in animal sources like liver, butter, fish, and eggs, which support epithelial cell growth, night vision, bone remodeling, and white blood cell production.

Carotenoids

A group of fat-soluble plant pigments including provitamin A forms (beta-carotene, alpha-carotene, and beta-cryptoxanthin) that can be converted into retinal, as well as non-provitamin forms such as lutein, lycopene, and zeaxanthin.

Carotenemia

A benign clinical condition characterized by a yellow-orange discoloration of the skin resulting from excessive dietary consumption of carotenoid-rich foods, harmlessly resolving upon reduced intake.

Xerophthalmia

An advanced manifestation of vitamin A deficiency characterized by keratin overproduction on the conjunctiva and cornea, recognized as the leading preventable cause of blindness worldwide.

$\alpha$-Tocopherol

The most biologically active isomer among the eight natural forms of vitamin E, functioning primarily as an antioxidant that protects polyunsaturated fatty acids (PUFAs) in cellular membranes from oxidative damage.

Ascorbic Acid

The chemical name for vitamin C, a water-soluble antioxidant that donates electrons, recycles oxidized vitamin E, enhances non-heme iron absorption, promotes white blood cell activity, and is mandatory for collagen synthesis.

Glutathione Peroxidase

A selenium-dependent antioxidant enzyme that converts toxic hydrogen peroxide ($\text{H}_2\text{O}_2$) into two stable molecules of water ($2\,\text{H}_2\text{O}$).

Keshan Disease

An endemic cardiomyopathy (heart muscle disease) resulting from severe selenium deficiency, associated with populations consuming foods grown in selenium-depleted soils.

Kashin-Beck Disease

A chronic, disabling deforming osteoarthritis linked to chronic dietary selenium deficiency in regions with low soil selenium concentration.

Phytochemicals

Bioactive, non-nutrient compounds produced by plants that are not essential for life and lack deficiency diseases, but exert protective functions such as inhibiting cancer initiation, mimicking hormones, and acting as antioxidants.

Major Minerals

Essential inorganic elements required by the human body in amounts of $100\,\text{mg}$ or greater per day, including calcium, phosphorus, magnesium, sodium, potassium, chloride, and sulfur.

Trace Minerals

Essential inorganic micronutrients required in daily quantities below $100\,\text{mg}$ (often measured in micrograms), such as iron, zinc, copper, iodine, selenium, and fluoride.

Trabecular Bone

Also called spongy bone; a porous, lattice-like internal bone structure common in vertebrae and the hip that is metabolically active and responds rapidly to mechanical loading, diet, hormones, and medications.

Cortical Bone

Also called compact bone; a dense, rigid outer bone tissue found predominantly along the shafts of long bones that is less metabolically active than trabecular bone, though susceptible to stress fractures during overtraining.

Dual Energy X-ray Absorptiometry (DXA)

A clinical radiological imaging modality that measures bone mineral density in $\text{g/cm}^2$ (commonly at the hip and lumbar vertebrae) for diagnosing osteoporosis and estimates whole-body fat and lean mass distribution.

Osteopenia

A condition of subnormal bone mineral density that is lower than peak reference values but has not declined sufficiently to reach the diagnostic threshold for osteoporosis.

Osteoporosis

A chronic, progressive skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue, predisposing individuals to low-trauma fragility fractures.

Hypercalcemia

An abnormally high concentration of calcium in the blood, representing the primary adverse toxicity consequence of excessive calcium or vitamin D intake.

Ergocalciferol ($\text{D}_2$)

The plant-derived, vegan form of vitamin D synthesized by fungi such as sun-exposed mushrooms; roughly four times the amount is required to equal the physiological activity of cholecalciferol.

Cholecalciferol ($\text{D}_3$)

The animal-associated, more metabolically active form of vitamin D synthesized endogenously in the skin from $7\text{-dehydrocholesterol}$ upon UVB light exposure and obtained through fatty fish or fortified foods.

Rickets

A childhood bone disorder caused by severe vitamin D or calcium deficiency in which growing bones fail to mineralize properly, remaining soft and bending outward under body weight.

Osteomalacia

The adult form of severe vitamin D deficiency characterized by progressive demineralization of mature bone, wherein the underlying matrix and structure persist but lose their mineral content.

Dental Fluorosis

A developmental disturbance of dental enamel caused by excessive fluoride consumption during tooth formation, presenting as white spots, mottling, or brown staining and pitting.

Osteocalcin

A vitamin K-dependent protein matrix synthesized by bone-forming cells that binds calcium ions and integrates them into the bone crystal lattice.

Heme Iron

The iron form bound within the porphyrin ring of hemoglobin and myoglobin in meat, poultry, and fish, characterized by a higher absorption rate of approximately $15\text{--}35\%$.

Non-Heme Iron

The elemental form of iron found in plant foods and enriched grains, absorbed at a lower baseline rate of $2\text{--}20\%$ and strongly modulated by dietary enhancers like vitamin C and inhibitors like phytates.

Hypochromic

A descriptive histological term for red blood cells that appear abnormally pale under microscopy due to a reduction in hemoglobin concentration, typically seen in iron deficiency anemia.

Hereditary Hemochromatosis

A genetic metabolic disorder that causes uncontrolled intestinal iron absorption and gradual, toxic accumulation of iron within body organs, most commonly diagnosed in males of Northern European ancestry.

Neural Tube Defects

Severe congenital birth abnormalities affecting the spinal column or brain (such as spina bifida and anencephaly) that occur within the first $21\,\text{days}$ post-conception due to insufficient maternal folate status.

Pernicious Anemia

An autoimmune megaloblastic anemia caused by the failure of the stomach lining to secrete intrinsic factor, impairing the terminal ileum's capacity to absorb vitamin $\text{B}_{12}$.

Goiter

An abnormal compensatory enlargement of the thyroid gland resulting from sustained thyroid-stimulating hormone (TSH) exposure in an effort to scavenge blood iodine during chronic iodine deficiency.

Cretinism

A congenital condition of irreversible cognitive impairment, deaf-mutism, and stunted somatic growth caused by severe maternal iodine deficiency and subsequent fetal hypothyroidism during gestation.

Hyponatremia

An abnormally low concentration of sodium in extracellular fluid and plasma, often precipitated by drinking excess pure water after profuse sweating or during rapid, high-volume water consumption.

Hypokalemia

A subnormal concentration of potassium in the blood, characterized clinically by loss of appetite, muscle weakness, severe cramping, cognitive confusion, and cardiac arrhythmias.

Pellagra

A classic nutritional deficiency disease caused by inadequate intake of niacin ($\text{B}_3$) or its precursor amino acid tryptophan, manifesting through the '4 Ds': dermatitis, diarrhea, dementia, and death.

Beriberi

The clinical deficiency syndrome resulting from thiamin ($\text{B}_1$) depletion, producing severe peripheral neuropathy, muscle wasting, cardiovascular dysfunction, and edema.

Wernicke-Korsakoff Syndrome

An acute neuropsychiatric disorder driven by severe thiamin ($\text{B}_1$) deficiency and alcohol abuse, clinically presenting with abnormal oculomotor movements, staggering ataxia, memory distortion, and brain ventricle enlargement.

Metabolic Water

Water generated internally within cells through the biochemical catabolism of macronutrients (carbohydrates, fats, and proteins), providing about $1\text{--}2.5\,\text{cups/day}$ ($200\,\text{mL/day}$) toward daily fluid balance.