Vitamins Flashcards
Body needs essential building blocks to grow and maintain itself
Carbohydrates
Fats
Proteins
Vitamins and minerals
Enzymes and coenzymes
Vitamins
Organic molecules needed in small quantities for normal metabolism and 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
Water-Soluble Vitamins
dissolved in?
excreted in?
Cannot be _____ by the body over long periods
______ required to prevent deficiencies
Vitamin B & C
B-complex group and vitamin C
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
Fat-Soluble Vitamins
Stored (Two) and excreted via?
Vitamins A, D, E, and K
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
Stored in the liver and fatty tissues
Deficiencies occur only after prolonged deprivation from an adequate supply or from disorders that prevent their absorption.
Daily intake not required unless one is deficient.
Vitamin A
also known as
sources
Also known as: Retinol, retinyl palmitate, and retinyl acetate
Fat soluble
Vitamin A comes from carotenes, which are found in plants (green and yellow vegetables and yellow fruits).
Vitamin A food sources:
liver, fish, dairy products, egg yolks, dark green leafy vegetables, and yellow-orange vegetables and fruits
Vitamin A: Functions
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
Vitamin A: Indications
Dietary supplement
-Infants and pregnant and nursing women
Deficiency states
-Hyperkeratosis of the skin
-Night blindness
Used to treat skin conditions
-Acne, psoriasis, keratosis follicularis
Concurrent use of isotretinoin and Vitamin A can result in additive effects and possible toxicity.
Vitamin A: Toxicity
Ingestion of excessive amounts causes toxicity.
Irritability, drowsiness, vertigo, delirium, coma, vomiting, diarrhea
Increased intracranial pressure in infants
Generalized peeling of the skin and erythema over several weeks
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
Vitamin D2–containing foods:
Fish liver oils, saltwater fish
Fortified foods: milk, bread, cereals
Animal livers, tuna fish, eggs, butter
Endogenous synthesis in the skin
Vitamin D: Functions
Works with parathyroid hormone to regulate absorption of and use of calcium and phosphorus.
Necessary for normal calcification of bone and teeth
Vitamin D: Indications
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
Vitamin D: Toxicity
Long-term ingestion of excessive amounts causes 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.
Forms of Vitamin D
calcifediol
calcitriol (Rocaltrol®)
dihydrotachysterol
ergocalciferol (Osto-D2®)
Vitamin E
Fat soluble
Four biologically active chemical forms: alpha(α)-, beta(β)-, gamma(γ)-, and delta(δ)- tocopherol
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.
Vitamin E food sources
Dietary plant sources:
Fruits, grains, fortified cereals, vegetable oils, wheat germ, nuts
Animal sources:
Eggs, chicken, meats, fish
Vitamin E: Indications
Highest risk of deficiency in
Dietary supplement
Antioxidant
Treatment of deficiency
Highest risk of deficiency in premature infants
Vitamin E: Adverse Effects
Very few acute adverse effects
Gastrointestinal (GI) tract
Central nervous system (CNS) effects
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.
Dietary sources of Vitamin K1:
Green leafy vegetables (broccoli, Brussels sprouts, cabbage, spinach, kale), cheese, soybean oils
Vitamin K: Functions
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)
Vitamin K: main indication
Reverses the effects of certain anticoagulants (warfarin)
Patient becomes unresponsive to warfarin for approximately 1 week after vitamin K administration.
Other:
Dietary supplementation
Treatment of deficiency states (rare)
Antibiotic therapy
Newborn malabsorption
Given prophylactically to newborn infants
Forms of Vitamin K
Vitamin K1 (phytonadione)
Vitamin K3 (menadione)
Water-Soluble Vitamins
Vitamin B complex
Thiamine (B1)
Riboflavin (B2)
Niacin (B3)
Pantothenic acid (B5)
Pyridoxine (B6)
Folic acid (B9)
Cyanocobalamin (B12)
Vitamin C
Ascorbic acid
Water-Soluble Vitamins Act as
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
Vitamin B1 (Thiamine) Food sources
Enriched whole grain breads and cereals, liver, beans, yeast
2 Vitamin B1 (Thiamine) deficiencies
Beriberi
Wernicke’s encephalopathy
Beriberi
Brain lesions, polyneuropathy of peripheral nerves, serous effusions, cardiac anatomical changes
Wernicke’s encephalopathy
Also known as cerebral beriberi
Vitamin B1 (Thiamine)
essential for?
maintains integrity of three systems?
Essential for:
Carbohydrate metabolism
Many metabolic pathways, including Krebs cycle
Maintains integrity of:
Peripheral nervous system
Cardiovascular system
GI tract
Vitamin B1 (Thiamine):Indications
Treatment of thiamine deficiency
-Beriberi
-Wernicke’s encephalopathy
-Peripheral neuritis associated with pellagra
-Neuritis of pregnancy (inflammation of peripheral nerves)
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.
Vitamin B2 (Riboflavin) Food sources:
Food sources:
Green, leafy vegetables
Eggs, dairy products
Nuts, legumes
Meats, liver
Yeast, enriched whole-grain products
Vitamin B2 (Riboflavin):Causes of Deficiency
Alcoholism a major cause
Also caused by:
Intestinal malabsorption
Long-standing infections
Liver disease
Malignancy
Probenecid therapy (gout treatment)
