Chapter 7 Flashcards
(49 cards)
What is Nutrient Density?
Measure of the nutrients a food provides relative to the energy it provides
Nutrient dense foods = more micronutrients/kcal
How are vitamin intake requirements measured?
Measured in micrograms (µg)
What are the sources of vitamins?
(1) Natural Sources: plants, animals, fungi, bacteria
(2) Synthetic: Made in labs by chemists using microbes
(3) Enrichment: Addition of vitamins and minerals to food products to replace those lost during processing
(4) Fortification: Addition of supplementary nutrients to food that were either not originally present or present in insignificant amounts
What are the water-soluble vitamins (B and C) do in terms of absorption?
Directly into the blood
What are the water-soluble vitamins (B and C) do in terms of transport
Travel freely in the blood
What are the water-soluble vitamins (B and C) do in terms of storage
Circulate freely in water-filled compartments of the body
What are the water-soluble vitamins (B and C) do in terms of excretion
Kidneys detect and remove excess in urine
When do the water-soluble vitamins (B and C) become toxic?
Possible to reach toxic levels when consumed from supplements
What are the water-soluble vitamins (B and C) requirements?
Needed in frequent doses (1-3/ day)
What are the fat-soluble vitamins (A, D, E and K) do in terms of absorption?
First into the lymph, then blood
What are the fat-soluble vitamins (A, D, E and K) do in terms of transport?
Many require transport proteins (chylomicrons)
What are the fat-soluble vitamins (A, D, E and K) do in terms of storage?
Stored in the cells associated with fat (fatty cells and liver)
What are the fat-soluble vitamins (A, D, E and K) do in terms of excretion?
Less readily excreted; tend to remain in fat-storage sites
When do fat-soluble vitamins (A, D, E and K) become toxic?
Likely to reach toxic levels when consumed from supplements
What are the fat-soluble vitamins (A, D, E and K) requirements?
Needed in periodic doses (weeks or even months)
What is meant by bioavailability?
Rate at/ extent to which a nutrient is absorbed and used.
Depends on: physiological needs, methods of preparation, dource, and combination of food you eat
What can be said about vitamin A?
Is fat-soluble. Found in several forms: retinol, retinal, retinoic acid
liver converts retinol into other two forms
What is beta-carotene?
Precursor to retinol provided by plants. It is a carotenoid
What is Retinol Activity Equivalent (RAE)?
Measure of Vitamin A activity
Where is Vitamin A stored?
Vitamin A is stored in the liver and fatty tissue
What are the major functions of vitamin A?
Provide explanantion to each
(1) Cell Differentiation
(2) Vision
(3) Antioxidant Functions
(1) Cells divide → differntiate. Maintains healthy cells in the mucus membranes
(2) Provides mucus to eye for it to clean itself
(3) antioxidants donate electrons to free radicals, stopping chain events
What happens to each major function of vitamin A if there is a deficiency?
(1) Cell Differentiation: increase rate of infection, cause damage in stomach from contact with hydrochloric acid, compromised epithelial cells → malabsorption of nutrients, keratinization of skin
(2) Vision: No mucus prevents ryr from cleaning itself. Debris accumulates → xerosis → blindness
(3) Antioxidant Functions: no stopping free radical chain effect. Causes cell damage, diseases, aging
What is needed for vitamin D?
What type of vitamin is it?
Sunlight + Chloesterol + Body Heat
fat-soluble vitamin
What are food sources of vitamin D?
Dairy products (often fortified)
