Vitamins Flashcards
Properties of Vitamin A
Fat soluble, stored in liver, carotene-precursor, provitamin; toxic level 10,000 IU
Function of Vitamin A
skin, vision
Sources of Vitamin A
yellow, orange fruits; dark green, leafy vegetables (cantaloupe, fish, liver, carrots, fortified skim milk, apricots, sweet potatoes)
Vitamin A Needs
M: 900 ug
F: 700 ug
Vitamin A deficiencies
night blindness (nyctalopia)-reversible;
Xerophthalmia (corneal damage)-not reversible
Bitot’s spots on conjunctiva
Dry, scaly skin (hyperkeratosis)
Properties of Vitamin D
Fat soluble
Cholesterol is precursor
UV light
7 dehydrocholesterol –> D3 cholecalciferol –> D2 –> ergocalciferol
Function of Vitamin D
Ca, P metabolism
Sources of Vitamin D
Sunlight, egg yolk, fortified milk
Vitamin D Needs
AI: 5-15 ug
Vitamin D Deficiencies
Rickets
Osteomalacia
Vitamin E Properties
Tocopherol, fat soluble, one of least toxic vitamins
UL: 1000 mgs
Vitamin E functions
antioxidant
resists hemolysis of RBC
Vitamin E sources
vegetable oils, whole grains, green vegetables, almonds
Vitamin E needs
15 mg
Vitamin E deficiencies
hemolytic anemia (RBC destroyed faster than they are made)
Vitamin K Properties
fat soluble, synthesized by bacteria in lower intestinal tract
no toxicity symptoms
Vitamin K functions
forms prothrombin in liver: aids in blood clotting
given pre-surgery
calcium metabolism
vitamin K sources
spinach, kale, broccoli, green leafy vegetables
vitamin K needs
M: 120 ug
F: 90 ug
Vitamin K deficiencies
hemorrhage
affected by mineral oil, antibiotics, and anticoagulants
Vitamin B1 Properties
Thiamin
water-soluble
lost as temp. or pH rises
heat stable in acid
B1 function
Thiamin
oxidation of CHO
increased CHO = increased need
metabolism of pyruvate
B1 sources
grains, wheat germ, pork, liver
B1 needs
M: 1.2
F: 1.1
B1 deficiencies
Beriberi, muscle weakness, foot drop, memory loss, tachycardia
decreased erythrocyte transketolase
increased plasma pyruvate
Vitamin B2 Properties
Riboflavin
lost in UV light
Vitamin B2 functions
energy release from protein
red cell production
B2 sources
liver, kidney, meat, milk
B2 needs
M: 1.3 mg
F: 1.1 mg
B2 deficiencies
growth failure
cheilosis- cracked lips
angular stomatitis: mouth, corner cracks, sore throat
Magenta tongue
Niacin properties
precursor: tryptophan
essential in all cells for energy production and metabolism
niacin functions
metabolism of CHO, protein, fat
niacin sources
protein, peanuts, ready-to-eat cereals, chicken, rice, yeast, milk
niacin needs
M: 16 NE
F: 14 NE
niacin deficiences
pellagra: dermatitis (skin irritation), diarrhea, dementia (3Ds for vitamin B3)
beefy, bright, red tongue
symmetrical, pigmented rash in sunlight
Folate properties
water-soluble
PABA is precursor
Folate functions
DNA synthesis, forms RBC in bone marrow, prevents neural tube defects
Folate sources
fortified dry cereal, liver, kidney, green leafy vegetables, citrus fruits, lentils, beans
Folate needs
400 ug
Folate deficienceis
megaloblastic, macrocytic anemia
diarrhea, fatigue
Vitamin B6 properties
pyridoxine
INH-isoniazid (B6 antagonist)
B6 functions
coenzyme in amino acid metabolism: deamination/transamination
increased PRO = increased pyridoxine
B6 sources
meat, wheat, corn, yeast, pork, liver, ready-to-eat cereals
B6 needs
M: 1.2-1.7 mg
F: 1.3-1.5 mg
B6 deficiencies
seizures, anemia, dermatitis, glossitis, peripheral neuropathy
B12 properties
Cyanocobalamin (man made source of vit B12)
contains cobalt
bound by intrinsic factor in gastric juice
B12 functions
coenzyme in PRO synthesis
forms RBC
B12 Sources
liver, meat, milk, kidney, eggs, fish, cheese
B12 needs
2.4 ug
B12 deficiencies
Microcytic, megaloblastic anemia pernicious anemia (B12 anemia)-after gastrectomy or removal of ileum due to lack of intrinsic factor
Pantothenic Acid functions
coenzyme A: energy
synthesis of fatty acids
Pantothenic Acid sources
animal foods, grains, legumes