Vitamins, Water, and Minerals

Comprehensive vocabulary flashcards covering fat-soluble vitamins, water-soluble vitamins, vitamin-like compounds, water balance, and major and trace minerals.

Vitamin

A complex organic compound that regulates specific metabolic processes in the body, cannot be synthesized in quantities adequate to maintain health, and whose chronic absence produces a deficiency disease that can be cured if resupplied in time.

Bioavailability

The extent to which the digestive tract absorbs a nutrient and how efficiently the body utilizes it.

Free Radical

A chemically unstable, highly reactive compound that possesses an unpaired electron, generated through oxidation reactions, which can remove electrons from stable cellular molecules.

Antioxidant

A protective substance that donates electrons to free radicals, neutralizing their reactive state and preventing oxidative damage to cellular components.

Retinoids

The preformed forms of vitamin A found exclusively in animal food sources, consisting of retinol, retinal, and retinoic acid.

Carotenoids

A group of plant pigments that function as phytochemical antioxidants, some of which ($\beta$-carotene, $\alpha$-carotene, and $\beta$-cryptoxanthin) serve as provitamin A precursors.

Carotenemia

A harmless, reversible yellow-orange discoloration of the skin resulting from high dietary intakes of beta-carotene and other carotenoids.

Rhodopsin

A light-sensitive photopigment located in retinal rod cells composed of the protein opsin bound to $11\text{-cis}$ retinal, essential for vision in dim light.

Xerophthalmia

A progressive ocular disease caused by vitamin A deficiency characterized by corneal drying, keratin buildup producing Bitot's spots, and eventual irreversible blindness.

Calcitriol

The biologically active hormonal form of vitamin D ($1,25\text{-dihydroxyvitamin D}_3$), synthesized by the kidneys from calcidiol, which stimulates calcium and phosphorus absorption.

Rickets

A pediatric vitamin D deficiency disorder characterized by failure of bones to mineralize properly, resulting in soft, malformed leg bones.

Osteomalacia

An adult condition characterized by softening and defective mineralization of bones resulting from prolonged vitamin D inadequacy.

Alpha-tocopherol

The primary biologically active form of vitamin E utilized by the human body that protects polyunsaturated fatty acids in cell membranes against lipid peroxidation.

Phylloquinone

The plant-derived form of vitamin K (vitamin $K_1$) that functions as a cofactor for carboxylase enzymes to activate blood-clotting factors.

Menaquinone

The form of vitamin K (vitamin $K_2$) found in animal and fermented foods and produced by gut bacteria (contributing approximately $10\%$ of the body's supply), which activates osteocalcin for bone mineralization.

Coenzyme

A small organic molecule, often derived from a water-soluble vitamin, that binds to an inactive enzyme to enable its catalytic activity.

Thiamin Pyrophosphate (TPP)

The active coenzyme form of thiamin (vitamin $B\text{-}1$) required by dehydrogenase enzymes for carbohydrate breakdown and branched-chain amino acid (BCAA) metabolism.

Beriberi

The thiamin deficiency disease characterized by extreme weakness, poor muscular coordination, and cardiovascular and nervous system dysfunction.

Wernicke-Korsakoff Syndrome

A degenerative brain disorder associated with severe thiamin deficiency, frequently linked to alcohol use disorder, causing abnormal eye movements, staggering gait, and cognitive impairment.

Ariboflavinosis

The riboflavin (vitamin $B\text{-}2$) deficiency disease characterized by inflammation of the mouth and throat, glossitis (swollen tongue), and cheilosis (cracking at mouth corners).

Niacin Equivalent (NE)

A standardized dietary unit equal to $1\,\text{mg}$ of niacin, representing the amount preformed in food or synthesized from $60\,\text{mg}$ of dietary tryptophan.

Pellagra

The niacin deficiency disease characterized by the four classic signs (the 4 D's): dermatitis, diarrhea, dementia, and death.

Coenzyme A (CoA)

The pantothenic acid (vitamin $B\text{-}5$)-containing coenzyme essential for delivering acetyl groups into the citric acid cycle and facilitating fatty acid synthesis.

Pyridoxal Phosphate (PLP)

The active coenzyme form of vitamin $B\text{-}6$ that facilitates transamination reactions in amino acid metabolism, neurotransmitter synthesis, and heme production.

Peripheral Neuropathy

Severe sensory nerve damage manifesting as numbness in the extremities and difficulty walking, caused by chronic megadoses of vitamin $B\text{-}6$ exceeding the Upper Limit of $100\,\text{mg/day}$.

Avidin

A protein present in raw egg whites that binds tightly to biotin and inhibits its gastrointestinal absorption.

Tetrahydrofolate (THF)

The active coenzyme form of folate (vitamin $B\text{-}9$) responsible for single-carbon methyl transfers essential for DNA synthesis and amino acid metabolism.

Megaloblastic Anemia

A condition characterized by large, immature, nucleated red blood cells released into the bloodstream due to impaired DNA replication caused by folate or vitamin $B\text{-}12$ deficiency.

Neural Tube Defects (NTDs)

Embryonic neural tube malformations, including spina bifida and anencephaly, associated with maternal periconceptional folate deficiency.

Intrinsic Factor (IF)

A glycoprotein secreted by gastric parietal cells that binds to vitamin $B\text{-}12$ in the small intestine, enabling its receptor-mediated absorption in the ileum.

Pernicious Anemia

An autoimmune form of megaloblastic anemia caused by antibody destruction of gastric parietal cells, resulting in intrinsic factor deficiency, vitamin $B\text{-}12$ malabsorption, and irreversible nerve damage.

Scurvy

The vitamin C deficiency disease resulting from defective collagen cross-linking, characterized by petechiae (pinpoint skin hemorrhages), swollen bleeding gums, tooth loss, and impaired wound healing.

Choline

A water-soluble vitamin-like nutrient necessary for the synthesis of the neurotransmitter acetylcholine, phospholipid cell membrane components (lecithin), and lipoproteins.

Carnitine

A conditionally essential nitrogenous compound synthesized in the liver from lysine and methionine that transports long-chain fatty acids into mitochondria for $\beta$-oxidation.

Intracellular Water

The body fluid compartment enclosed within cell membranes, representing approximately two-thirds of total body water, with potassium and phosphate as primary ions.

Extracellular Water

The fluid compartment outside cells, divided into interstitial fluid and blood plasma, with sodium and chloride as primary ions.

Antidiuretic Hormone (ADH)

A peptide hormone secreted by the posterior pituitary gland in response to dehydration that instructs the kidneys to reabsorb water and reduce urinary volume.

Aldosterone

A steroid hormone secreted by the adrenal cortex that increases renal tubular reabsorption of sodium ions ($\text{Na}^+$), prompting water retention via osmosis to restore blood volume.

Renin-Angiotensin System

A physiological cascade activated by low blood pressure wherein renal renin converts angiotensinogen to angiotensin I, followed by ACE conversion to angiotensin II, causing vasoconstriction and aldosterone release.

Water Intoxication

A clinical condition resulting from consuming excessive water faster than the kidneys can excrete it, leading to dangerous dilution of serum sodium (hyponatremia).

Major Minerals

Essential inorganic nutritional elements required by the human body in amounts of $100\,\text{mg/day}$ or greater (e.g., calcium, phosphorus, sodium, potassium).

Phytic Acid (Phytates)

A plant constituent found in whole grains, seeds, and beans that acts as an antinutrient by binding divalent minerals like iron, zinc, and calcium, reducing their intestinal absorption.

Oxalic Acid (Oxalates)

An organic compound present in foods like spinach and sweet potatoes that binds dietary calcium, significantly depressing its bioavailability.

Parathyroid Hormone (PTH)

A hormone secreted by the parathyroid glands when blood calcium falls below $8.5\,\text{mg/dL}$ that stimulates osteoclast bone resorption, promotes renal calcium conservation, and activates vitamin D.

Calcitonin

A hormone produced by the thyroid gland in response to elevated blood calcium ($> 10.8\,\text{mg/dL}$) that stimulates osteoblast bone building and suppresses renal calcium reabsorption.

Osteoporosis

A chronic metabolic bone disease characterized by loss of bone mineral mass, porous microarchitecture, and elevated risk of skeletal fractures.

Depolarization

The initial rapid phase of a nerve impulse where extracellular sodium ($\text{Na}^+$) rushes into the axon, transitioning the membrane potential from negative to positive.

Repolarization

The restorative phase of an action potential where intracellular potassium ($\text{K}^+$) flows out of the neuron, returning the electrical potential to its resting negative state.

Hypokalemia

Abnormally low blood potassium concentration characterized by muscular cramps, fatigue, constipation, cardiac arrhythmias, and increased urinary calcium loss.

Hypermagnesemia

Abnormally high serum magnesium levels, typically induced by non-dietary intake from magnesium-containing antacids or laxatives, resulting in severe diarrhea and toxicity in individuals with renal failure.

DASH Diet

The 'Dietary Approaches to Stop Hypertension' eating plan, structured to be rich in potassium, calcium, magnesium, fruits, vegetables, and low-fat dairy while restricting sodium, saturated fat, and added sugars.

Trace Minerals

Essential mineral micronutrients required by the human body in amounts less than $100\,\text{mg/day}$ (e.g., iron, zinc, copper, iodine, selenium).

Heme

The iron-containing organic porphyrin ring structure found within hemoglobin and myoglobin that coordinates with an $\text{Fe}^{2+}$ ion to bind oxygen molecules.

Nonheme Iron

The inorganic form of dietary iron found in plant foods, iron supplements, and enriched grain products, whose intestinal absorption is less efficient but can be enhanced by ascorbic acid (vitamin C).

Ferritin

The major intracellular iron-storage protein synthesized by enterocytes and hepatocytes that traps iron to prevent toxicity and is shed with desquamated cells when stores are replete.

Transferrin

The primary transport glycoprotein in blood plasma that accepts absorbed iron and circulates it to bone marrow and peripheral tissues.

Goiter

An abnormal enlargement of the thyroid gland caused by insufficient dietary iodine intake (or iodine excess), resulting in excessive TSH stimulation.

Zinc-Finger Motifs

Zinc-stabilized structural loops within transcription factors that allow them to bind directly to specific DNA sequences to regulate gene expression.

Cu/Zn Superoxide Dismutase (SOD)

A cytosolic antioxidant metalloenzyme containing copper and zinc cofactors that catalyzes the conversion of harmful superoxide radicals into hydrogen peroxide.

Selenoproteins

A class of selenium-dependent functional proteins, notably including glutathione peroxidase, that reduce reactive hydrogen peroxide to water.

Dental Fluorosis

An irreversible defect in tooth enamel development caused by chronic ingestion of excess fluoride during odontogenesis, appearing as white striations, discoloration, or pitting.

Wilson Disease

A rare autosomal recessive disorder of copper metabolism that blocks hepatic copper excretion into bile, leading to copper accumulation in organs and golden-brown Kayser-Fleischer rings in the cornea.

Menkes Syndrome

A rare genetic disorder characterized by impaired copper absorption from the intestinal mucosa into the circulation, resulting in severe copper deficiency and neurodevelopmental delay.