252 Pharmacology - Vitamins and Minerals Flashcards
What are vitamins and their role in the body?
- Organic molecules needed in small quantities for normal metabolism and other biochemical functions, such as growth or repair of tissue
- Attach to enzymes or coenzymes and help them activate anabolic (tissue-building) processes
- Natural sources from both plants and animals
- Insufficient amounts result in various deficiencies
What are water-soluble vitamins?
- Can be dissolved in water
- Easily excreted in the urine
- Cannot be stored by the body over long periods
- Daily intake required to prevent deficiencies
- Controversy about “megadosing”
List two water-soluble vitamins.
- B-complex group of vitamins
- Vitamin C
What are fat-soluble vitamins?
- Present in both plant and animal foods
- Stored primarily in the liver
- Exhibit slow metabolism or breakdown
- Excreted via the feces
- Can be toxic when consumed in excess
List four fat-soluble vitamins.
- Vitamin A
- Vitamin D
- Vitamin E
- Vitamin K
Where are fat-soluble vitamins stored?
Liver and fatty tissues
What are other names for Vitamin A?
Also known as: Retinol, retinyl palmitate, and retinyl acetate
What are some food sources of Vitamin A?
- liver
- fish
- dairy products
- egg yolks
- dark green leafy vegetables
- and yellow-orange vegetables and fruits
Where does Vitamin A come from?
Vitamin A comes from carotenes, which are found in plants (green and yellow vegetables and yellow fruits).
List the functions of Vitamin A
- Required for growth and development of bones and teeth (morphogenesis)
- Essential for night and normal vision (rhodopsin)
- Necessary for other processes
- Reproduction
- Integrity of mucosal and epithelial surfaces
- Cholesterol and steroid synthesis
What are the indications for Vitamin A?
- Dietary supplement
- Infants and pregnant and nursing women
- Deficiency states
- Hyperkeratosis of the skin
- Night blindness
- Other conditions
- Used to treat skin conditions
- Acne, psoriasis, keratosis follicularis
What interaction is there for Vitamin A?
Concurrent use of isotretinoin and Vitamin A can result in additive effects and possible toxicity
What are the physical consequences of Vitamin A toxicity?
- Irritability, drowsiness, vertigo, delirium, coma, vomiting, diarrhea
- Increased intracranial pressure in infants
- Generalized peeling of the skin and erythema over several weeks
List the characteristics of Vitamin D
- Fat soluble
- “Sunshine vitamin”
- Responsible for proper utilization of calcium and phosphorus
- Vitamin D2 (ergocalciferol)
- Plant vitamin D
- Obtained through dietary sources
- Vitamin D3 (cholecalciferol)
- Produced in the skin by ultraviolet irradiation
Which foods contain vitamin D2?
- Fish liver oils, saltwater fish
- Fortified foods: milk, bread, cereals
- Animal livers, tuna fish, eggs, butter
What are the functions of vitamin D?
- Works with parathyroid hormone to regulate absorption of and use of calcium and phosphorus.
- Necessary for normal calcification of bone and teeth
What are the indications for Vitamin D?
- Dietary supplement
- Treatment of vitamin D deficiency
- Treatment and correction of conditions related to long-term deficiency: rickets, tetany, osteomalacia
- Prevention of osteoporosis
- Other uses: treatment of osteodystrophy, hypocalcemia, hypoparathyroidism, pseudohypoparathyroidism, hypophosphatemia
What are physical consequences of vitamin D toxicity?
- Hypertension, dysrhythmias, weakness, fatigue, headache, drowsiness
- Anorexia, dry mouth, metallic taste, nausea, vomiting, constipation
- Decreased bone growth, bone pain, muscle pain
- Polyuria, albuminuria, increased blood urea nitrogen level
- Can progress to impairment of renal function and osteoporosis if left untreated.
List four different forms of vitamin D
- calcifediol
- calcitriol (Rocaltrol®)
- dihydrotachysterol
- ergocalciferol (Osto-D2®)
List the characteristics of Vitamin E
- Fat soluble
- Four biologically active chemical forms: alpha(α)-, beta(β)-, gamma(γ)-, and delta(δ)- tocopherol
What are plant sources of vitamin E?
- Fruits, grains, fortified cereals, vegetable oils, wheat germ, nuts
What are animal sources of vitamin E?
ØEggs, chicken, meats, fish
What are the functions of Vitamin E?
- The exact biological function of vitamin E is unknown.
- Believed to act as an antioxidant
- Unproved theory that vitamin E has beneficial effects for patients with cancer, heart disease, Alzheimer’s disease, premenstrual syndrome, and sexual dysfunction
- Results from the Heart Outcomes Prevention Evaluation trial showed no benefit of vitamin E supplementation.
What are the indications for Vitamin E?
- Dietary supplement
- Antioxidant
- Treatment of deficiency
- Highest risk of deficiency in premature infants
What are the adverse effects of vitamin E?
- Very few acute adverse effects
- Gastrointestinal (GI) tract
- Central nervous system (CNS) effects
List the characteristics of vitamin K.
- Fat soluble
- Three types: phytonadione (vitamin K1), menaquinone (vitamin K2), and menadione (vitamin K3)
- Body does not store large amounts of vitamin K.
- Vitamin K2 is synthesized by the intestinal flora
What are dietary sources of K1?
- Green leafy vegetables (broccoli, Brussels sprouts, cabbage, spinach, kale)
- Cheese
- Soybean oils
What are the functions of vitamin K?
- Essential for synthesis of blood coagulation factors in the liver
- Vitamin K–dependent clotting factors
- Factor II (prothrombin)
- Factor VII (proconvertin)
- Factor IX (Christmas factor)
- Factor X (Stuart-Prower factor)
What are the indications for vitamin K?
- Dietary supplementation
- Treatment of deficiency states (rare)
- Antibiotic therapy
- Newborn malabsorption
- Given prophylactically to newborn infants
- Reverses the effects of certain anticoagulants (warfarin)
- Patient becomes unresponsive to warfarin for approximately 1 week after vitamin K administration.
List the 7 B vitamins that make up the Vitamin B complex.
- Thiamine (B1)
- Riboflavin (B2)
- Niacin (B3)
- Pantothenic acid (B5)
- Pyridoxine (B6)
- Folic acid (B9)
- Cyanocobalamin (B12)
What is vitamin B1?
Thiamine
What is Vitamin B2?
Riboflavin
What is vitamin B3?
Niacin
What is Vitamin B5?
Pantothenic acid
What is vitamin B6?
Pyridoxine
What is vitamin B9?
Folic acid
What is vitamin B12?
Cyanocobalamin
What is another name for Vitamin C?
ascorbic acid
What are the characteristics of water-soluble vitamins?
- Can dissolve in water
- Present in plant and animal food sources
- Excessive amounts excreted in the urine, not stored in the body
- Toxic reactions very rare
- Act as coenzymes or oxidation-reduction agents
What are food sources of Vitamin B1 (thiamine)?
- Enriched whole grain breads and cereals
- liver
- beans
- yeast
What does a vitamin B1 deficiency lead to?
- Beriberi
- Brain lesions, polyneuropathy of peripheral nerves, serous effusions, cardiac anatomical changes
- Wernicke’s encephalopathy
- Aka cerebral beriberi
What are the functions of Vitamin B1 (Thiamine)?
- Essential for:
- Carbohydrate metabolism
- Many metabolic pathways, including Krebs cycle
- Maintains integrity of:
- Peripheral nervous system
- Cardiovascular system
- GI tract
What are the indications for Vitamin B1 (Thiamine)?
- Treatment of thiamine deficiency
- Beriberi
- Wernicke’s encephalopathy
- Peripheral neuritis associated with pellagra
- Neuritis of pregnancy
- Metabolic disorders
- Malabsorption
- Management of poor appetite, ulcerative colitis, chronic diarrhea, and cerebellar syndrome or ataxia
- Suggested as oral insect repellent, but studies do not support this.
What are food sources for Vitamin B2 (Riboflavin)?
- Green, leafy vegetables
- Eggs, dairy products
- Nuts, legumes
- Meats, liver
- Yeast, enriched whole-grain products
What are some causes of Vitamin B2 (riboflavin) deficiency?
- Alcoholism a major cause
- Also caused by:
- Intestinal malabsorption
- Long-standing infections
- Liver disease
- Malignancy
- Probenecid therapy
What are the functions of vitamin B2 (riboflavin)?
- Converted into two coenzymes essential for tissue respiration
- Required to activate vitamin B6 (pyridoxine)
- Converts tryptophan into niacin
- Maintains erythrocyte integrity
What are the consequences of a vitamin B2 (riboflavin) deficiency?
- Deficiency results in cutaneous, oral, and corneal changes:
- Cheilosis (chapped or fissured lips)
- Seborrheic dermatitis
- Keratitis
What are the indications for Vitamin B2 (riboflavin)?
- Dietary supplement
- Treatment of deficiency
- Microcytic anemia
- Acne
- Migraine headaches
What is an effect of vitamin B2 (riboflavin) on that body to let patients know about?
Large doses discolour urine yellow orange
What are food sources of Vitamin B3 (niacin)?
- Beans, turkey, tuna, liver, yeast, peanuts
- Enriched whole-grain breads and cereals, wheat germ
- Also synthesized from tryptophan (an essential amino acid obtained from protein digestion)
What are the functions of Vitamin B3 (niacin)?
- Once ingested, converted to nicotinamide
- Nicotinamide is converted to two coenzymes.
- These enzymes are required for:
- Glycogenolysis and tissue respiration
- Carbohydrate, lipid, protein, and purine metabolism
What are the indications for vitamin B3 (niacin)?
- Prevention and treatment of pellagra
- Management of dyslipidemia
- Beneficial effect in peripheral vascular disease
What is a consequence of vitamin B3 deficiency?
- Pellagra: niacin deficiency
- Mental: various psychotic symptoms
- Neurological: neurasthenic syndrome
- Cutaneous: crusting, erythema, desquamation of skin, scaly dermatitis
- Inflammation of mucous membranes: oral, vaginal, and urethral lesions; glossitis
- GI: diarrhea or bloody diarrhea
What are the adverse effects of vitamin B3 (niacin) at higher doses?
- Adverse effects seen when higher doses are used in the treatment of dyslipidemia:
- Flushing
- Pruritus
- GI distress
What are food sources of Vitamin B6 (pyridoxine)?
- Whole grains, wheat germ, yeast, fortified cereals
- Fish, organ meats, poultry, meats, eggs
- Peanuts, nuts, vegetables, bananas
What are the three compounds of vitamin B6 (pyridoxine)?
- Composed of three compounds
- Pyridoxine
- Pyridoxal
- Pyridoxamine
- All three are converted in the erythrocytes to active forms of B6
What are the functions of vitamin B6 (pyridoxine)?
- Necessary for many metabolic functions
- Protein, lipid, and carbohydrate utilization
- Conversion of tryptophan to niacin
- Necessary for integrity of peripheral nerves, skin, mucous membranes, hematopoietic system
What are signs and symptoms of vitamin B6 (pyridoxine) deficiency?
- Sideroblastic anemia
- Neurological disturbances
- Seborrheic dermatitis
- Cheilosis (chapped, fissured lips)
- Xanthurenic aciduria
What are the causes of vitamin B6 (pyridoxine) deficiency?
- Inadequate intake
- Poor absorption
- Uremia, alcoholism, cirrhosis, hyperthyroidism, malabsorption, heart failure
- Drug-induced
- Isoniazid for tuberculosis
- Hydralazine for hypertension
What indications are there for vitamin B6 (pyridoxine)?
- Vitamin B6 deficiency
- Seizures that are unresponsive to usual therapy
- Morning sickness during pregnancy
- Patients with various metabolic disorders may respond to pyridoxine therapy.
True or false. Neurotoxicity is possible with large doses of vitamin B6 (pyridoxine)?
True
How is Vitamin B12 (cyanocobalamin) synthesized?
Synthesized by microorganisms present in the body
What are food sources of vitamin B12 (cyanocobalamin)?
- Liver, kidney, fish, shellfish, poultry, milk
- Eggs, blue cheese, fortified cereals
What are the functions of vitamin B12 (cyanocobalamin)?
- Present as two different coenzymes
- Required for many metabolic pathways
- Fat and carbohydrate metabolism
- Protein synthesis
- Growth, cell replication
- Hematopoiesis
- Nucleoprotein and myelin synthesis
What is the most common manifestation of untreated cyanocobalamin deficiency?
pernicious anemia
What does a vitamin B12 (cyanocobalamin) deficiency lead to?
- Neurological damage
- Megaloblastic anemia
What causes a vitamin B12 (cyanocobalamin) deficiency?
- Malabsorption
- Poor dietary intake of animal-origin foods (as in vegetarians)
What is required for the oral absorption of vitamin B12 (cyanocobalamin)?
- Oral absorption of vitamin B12 (extrinsic factor) requires presence of the intrinsic factor.
- The intrinsic factor is a glycoprotein secreted from the gastric parietal cells.
What are food sources of Vitamin C (ascorbic acid)?
- Citrus fruits, strawberries
- Tomatoes, potatoes
- Broccoli, spinach, Brussels sprouts
- Cabbage, green peppers
- Liver
True of false. Vitamin C (ascorbic acid) can also be synthesized.
True
What are the functions of Vitamin C (ascorbic acid)?
- Acts in oxidation-reduction reactions
- Required for several metabolic activities:
- Collagen synthesis
- Maintenance of connective tissue
- Tissue repair
- Maintenance of bone, teeth, and capillaries
- Folic acid metabolism
- Erythropoiesis
- Enhances absorption of iron
- Required for the synthesis of:
- Lipids
- Proteins
- Steroids
- Aids in cellular respiration
- Aids in resistance to infections
What can a prolonged deficiency in vitamin C (ascorbic acid) lead to?
- Prolonged deficiency results in scurvy
- Weakness
- Gingivitis and bleeding gums
- Loss of teeth
- Anemia
- Subcutaneous hemorrhage
- Bone lesions
- Delayed healing of soft tissues and bones
- Hardening of leg muscles
What are indications for vitamin C (ascorbic acid)?
- Dietary supplement
- Prevention and treatment of scurvy
- Urinary acidifier
- Most large controlled studies have shown that ascorbic acid has little or no value as a prophylactic for the common cold
What are the effects of megadoses of vitamin C (ascorbic acid)?
- Megadoses may cause:
- Nausea, vomiting, headache, and abdominal cramps
- Acidified urine, with possible stone formation
- Discontinuing megadoses may result in scurvy-like symptoms
What are the characteristics of minerals?
- Essential nutrients
- Inorganic compounds
- Bind with enzymes or other organic molecules
- Help to regulate many bodily functions
- Muscle contraction
- Nerve transmission
- Production of hemoglobin
- Building blocks for many body structures
- Required for intracellular and extracellular body fluid electrolytes
- Macrominerals
- Microminerals, or trace elements
What is the most abundant mineral element in the body?
Calcium
What other vitamin must be present in adequate amounts for calcium to be absorbed?
Vitamin D
What are food sources of calcium?
- Especially milk and dairy products
- Fortified cereals
- Calcium-fortified orange juice
- Sardines, salmon
What are the functions of calcium?
- Essential for normal maintenance and function of:
- Nervous, muscular, and skeletal systems.
- Cell membrane and capillary permeability.
- Catalyst in many enzymatic reactions
- Essential in many physiologic processes
- Transmission of nerve impulses
- Contraction of cardiac, smooth, and skeletal muscles
- Renal function, respiration, and blood coagulation
What are the physical consequences of hypocalcemia?
- Infantile rickets
- Adult osteomalacia
- Osteoporosis
What are some common causes of calcium deficiency?
- Inadequate intake of calcium or vitamin D
- Hypoparathyroidism
- Malabsorption syndrome
What are the indications for calcium?
- Achlorhydria
- Alkalosis
- Chronic diarrhea
- Hyperphosphatemia
- Hypoparathyroidism
- Menopause
- Pancreatitis
- Pregnancy and lactation
- Premenstrual syndrome
- Renal failure
- Sprue
- Steatorrhea
- Vitamin D deficiency
- Adult osteomalacia
- Hypoparathyroidism
- Infantile rickets or tetany
- Muscle cramps
- Osteoporosis
- Kidney insufficiency
What are physical consequences of hypercalcemia?
- Anorexia
- Nausea
- Vomiting
- Constipation
- Severe hypercalcemia can cause:
- Heart irregularities
- Delirium
- Coma
What drug interactions of note are there for calcium?
- Chelation
- Calcium salts will bind (chelate) with tetracyclines to produce an insoluble complex
- If hypercalcemia is present in patients taking digoxin, serious cardiac dysrhythmias can occur.
What is magnesium required for?
- One of the principal cations of intracellular fluid
- Essential for enzyme systems associated with energy metabolism
- Required for:
- Nerve function
- Muscle contraction
What are dietary sources of magnesium?
- Green leafy vegetables
- Meats, seafood, milk, cheese, yogurt
- Bran cereal, nuts
With what diets is magnesium required in higher amounts?
Required in higher amounts for those with diets high in protein-rich foods, calcium, and phosphorus
What are causes of hypomagnesemia?
- Malabsorption
- Alcoholism
- Long-term intravenous feedings
- Diuretics
- Metabolic disorders (hyperthyroidism, diabetic ketoacidosis)
What are indications for magnesium?
- Magnesium deficiency
- Anticonvulsant in magnesium deficiency
- Pre-eclampsia and eclampsia
- Tocolytic drug for inhibition of uterine contractions in premature labour
- Pediatric acute nephropathy
- Cardiac dysrhythmias
- Constipation (short-term treatment)
What adverse effects can be caused by hypermagnesemia?
- Tendon reflex loss
- Difficult bowel movements
- CNS depression
- Respiratory distress
- Heart block
- Hypothermia
What are food sourced of phosphorus?
- Milk, yogurt, cheese
- Peas, meats, fish, eggs
What are non-dietary causes of phosphorus deficiency?
- Malabsorption
- Extensive diarrhea or vomiting
- Hyperthyroidism
- Long-term use of aluminum or calcium antacids
- Liver disease
What are the functions of phosphorus?
- Required precursor for the synthesis of essential body chemicals
- Building block for body structures
- Required for the synthesis of:
- Nucleic acid
- Adenosine diphosphate
- Adenosine monophosphate
- Adenosine triphosphate
- Responsible for cellular energy transfer
- Necessary for the development and maintenance of the skeletal system and teeth
What are the adverse effects of phosphorus?
- Diarrhea
- Nausea and vomiting
- Other GI disturbances
- Confusion
- Weakness
- Breathing difficulties
Name an important trace element in the body.
Zinc
What are the functions of zinc?
- Essential in metabolic reactions of proteins and carbohydrates
- Important for normal tissue growth and repair, especially wound repair
What are food sources of zinc?
- Red meats, liver,
- oysters
- milk products,
- eggs,
- beans,
- nuts,
- whole grains,
- fortified cereals,
- certain seafoods
What assessments do you complete when administering vitamins and minerals?
- Assess nutritional status.
- Assess baseline lab values (hemoglobin, hematocrit, white blood cell count, red blood cell count, protein, albumin levels).
- Assess history and medication history.
- Assess for contraindications.
