Tags & Description
what is the literal meaning of vitamin?
vita- necessary for life / amine- type of nitrogen- containing substance. the term vitamine was changed to vitamin after it was determined that there were several kinds of these substances and not all were amines
list at least three criteria used to designate a substance as a vitamin
cannot be synthesized by the body or make enough to maintain good health, occurs naturally in foods, deficiency disorder occurs if substance is missing from the body or is not properly metabolized, health is restored by supplying missing substance
identify the four- fat soluble vitamins
A, D, E, K
describe how antioxidants protect against free- radical damage
antioxidants give up electrons to free radicals to protect cells. they protect molecules in cells, such as polyunsaturated fatty acids and DNA, from being oxidized.
list at least three factors that affect the bioavailability of a vitamin
life stage and individual's nutrient status, changes to GI transit time, health conditions affecting absorption of fat, food processing and preparation techniques, source of vitamin
discuss at least five ways to preserve the vitamin content of fruits and veggies during food preparation and storage
store fresh produce at temperatures near freezing, in high humidity, away from air, avoid exposure to excessive heat, alkaline substances, light, and air, cook vegetables in small amounts of water, using quick cook methods (stir- frying and steaming), consume highly perishable produce like berries and leafy veggies soon after harvest or purchase
what feature makes vitamins A, D, E, and K soluble in fat?
all include a hydrocarbon chain
major functions of vitamin A
participates in cell production, growth, development, function, maintenance, and vision
major functions of vitamin D
regulation of calcium and maintenance of phosphorus levels in the blood, adn the production and maintenance of healthy bones
major functions of vitamin K
functions as a cofactor in a number of biochemical pathways, including blood clotting, (K2)- bone metabolism and cardiovascular health, regulates calcium in the body and prevents the deposition of calcium in soft tissues, such as blood vessels
major functions of vitamin E
protects polyunsaturated fatty acids in cell membranes from being damaged by free radicals, other roles include: maintaining nervous tissue and immune system function
name the three active forms of vitamin A
retinol, retinal, retinoic acid
good food sources of preformed vitamin A
liver, butter, fish liver oils, eggs
good food sources of beta- carotene
carrots, spinach, other leafy greens, pumpkin, sweet potatoes, broccoli, mangoes, cantaloupe
explain the role of vitamin A in preventing night blindness
rods and cones need vitamin A to function properly, specifically retinol. rods convert retinol to retinal. Retinal binds to protein opsin to form rhodopsin in dark conditions.
good food sources of vitamin D
salmon, herring, catfish, vitamin D fortified- milk, cereal, orange juice, margarine
what groups of people are at the greatest risk for rickets and osteomalacia, and why?
adults confined indoors or almost fully covered when outside
what form of vitamin E has the highest biological activity?
alpha- tocopherol
good food sources of vitamin E
sunflower seeds, almonds, plant oils and products made from them, fish, whole grains, nuts and seeds, certain vegetables
explain the consequences of a vitamin E deficiency
nerve damage, loss of neuromuscular control, blindness, reduced function of immune system
identify the three forms of vitamin K and their relationship to each other
phylloquinone: vitamin K1, menaquinone: vitamin K2, menadione: can be converted into menaquinone in the body
describe the role of vitamin K in clotting blood
when vitamin K1 is unavailable, the blood- clotting factors are inactive, and the blood does not clot effectively
good food sources of vitamin K
green leafy vegetables, broccoli, green beans, egg yolks, butter, certain cheeses, liver, beef, some fermented foods
explain the consequences of vitamin K deficiency
abnormal blood clotting and bleeding
explain the consequence of vitamin K toxicity
antagonistic reaction to vitamin E
qualities of fat- soluble vitamins as it pertains to solubility and storage
soluble in fat, stored in the body (esp. liver)
qualities of water- soluble vitamins as it pertains to solubility and storage
soluble in water, not stored to any significant degree