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