Fat Soluble Vitamins Flashcards
Historical Perspective Certain foods were known to cure illnesses resulting from what we now recognize to be “vitamin deficiencies”.
For example, ancient Egyptians treated night blindness with a topical application of juice extracted from the liver.(Vitamin A)
Certain foods were known to cure illnesses resulting from what we now recognize to be “vitamin deficiencies”. For example, ancient Egyptians treated night blindness with a topical application of juice extracted from the liver.(Vitamin A)
Liver is now recognized as a rich source of vitamin___.
Today, we know that vitamin A plays a crucial role in maintenance of__ ___ particularly in ___light.
Liver is now recognized as a rich source of vitamin A. Today, we know that vitamin A plays a crucial role in maintenance of good vision, particularly in low light.
Current and Future Research on Vitamins… It took some time to uncover the true nature of various vitamins. Certain vitamins such as vitamins _ and _ can be synthesized in the body. More to come!
It took some time to uncover the true nature of various vitamins. Certain vitamins such as vitamins D and K can be synthesized in the body. More to come!
Fat-Soluble Vitamins: Vitamins A, D, E, and K
Absorption First into the ___, then the___
Transport Many require p___ ___
Storage ___ in the cells associated with___
Excretion __ readily excreted, tend to remain in __ ___ sites
Toxicit___ to reach toxic levels, when consumed from supplements
Requirements Needed in____ doses (perhaps weeks or even months)
Absorption First into the lymph, then the blood Transport Many require protein carriers Storage Trapped in the cells associated with fat Excretion Less readily excreted, tend to remain in fat-storage sites Toxicity Likely to reach toxic levels, when consumed from supplements Requirements Needed in periodic doses (perhaps weeks or even months)
Absorption of Fat-Soluble Vitamins
Digestive processes in stomach release vitamins from food
____ produced in ___ and stored in__ ___aids in absorption
Digestive enzymes released by____as help to further release vitamins (esp__)
Essentially all absorptoion takes place in __ ___. Fat soluble vit are absorbed along with __ ___
Small amts of vit __ and ___ are made by bact in terminal part of small intes and large intestine; some may be ___
Absorption of Fat-Soluble Vitamins
Digestive processes in stomach release vitamins from food
Bile produced in liver and stored in gall bladder aids in absorption
Digestive enzymes released by pancreas help to further release vitamines (esp A)
Essentially all absorptoion takes place in small intestine. Fat soluble vit are absorbed along with dietary fat
Small amts of vit K and biotin are made by bact in terminal part of small intes and large intestine; some may be absorbed
Forms of Vitamin A
Provitamin is ___ ____
Forms:
___
___
___ ___
Forms of Vitamin A
Provitamin is Beta Carotene
Forms:
Retinol
Retinal
Retinoic Acid
Conversion of Vitamin A
___ ____(in animal foods)–>_____ (supports reproduction)<–>_____ (participates in vision)–>+____ (Regulates Growth)
___ ____(in plant foods)–> ____
Conversion of Vitamin A
Retynl esters (in animal foods)à Retinol (supports reproduction)ßàRetinal (participates in vision)àRetinoic acid (Regulates Growth)
Beta carotene (in plant foods)à Retinal
Food Sources: Vitamin A and Beta-carotene
Food Sources: Vitamin A and Beta-carotene
Liver
Sweet potato
Carrots
Milk
Apricots
Spinach
Current Unit of Measurement of Vitamin A 1µg of ____ = 1 __ ___ ____ (RAE)
____ of Beta-carotene = 1µg of retinol
1µg of retinol = 1 Retinol Activity Equivalent (RAE) 12µg of Beta-carotene = 1µg of retinol
Primary Functions Role in Vision
Light causes a change in ___ and retinal (trans form) is released. This change in ____n to ___ and trans ____ in turn initiates a ___ to the brain.
Rhodopsin is then ___ after forming___ back into its original shape (___ form)
Some retinal is ___from the cycle. This must be replaced by ___ from the _____. It is converted to retinal in the ____
Role in Vision
Light causes a change in retinal and retinal (trans form) is released. This change in rhodopsin to opsin and trans retinal in turn initiates a signal to the brain.
Rhodopsin is then rebuilt after forming retinal back into its original shape (cis form)
Some retinal is lost from the cycle. This must be replaced by retinol from the bloodstream. It is converted to retinal in the eye.
Other Functions of Vitamin A
Cell ____
Integrity of ___ __
Integrity of ___ ___
Necessary for___ ___ __ and possibly other aspects of__ ___
Support of __ ___
Other Functions of Vitamin A Cell Differentiation Integrity of epithelial cells Integrity of mucous membrane Necessary for T-lymphocyte function and possibly other aspects of immune function Support of normal growth
Recommended Dietary Allowances (RDA) (according to Institute of Medicine) Adults (19-50 years) Men - ___µg of retinol (3,000 I.U.) Women - ___µg of retinol (2,333 I.U.)
Adults (19-50 years) Men - 900µg of retinol (3,000 I.U.) Women - 700µg of retinol (2,333 I.U.)
Deficiency of Vitamin A
Symptoms of deficiency include ____, ___ ___, ___ ___ to ____, ____ of ____ ___ of the ____
Deficiency of Vitamin A Symptoms of deficiency include anorexia, retarded growth, increased susceptibility to infections, keratinization of epithelial cells of the skin, etc.
____ _____
Follicular Hyperkeratosis
_____
Xeropthalmia
Vitamin A Deficiency and Blindness
Worldwide, vitamin A deficiency is the ___ leading cause of blindness. ___-____ cases are reported every year.
Worldwide, vitamin A deficiency is the second leading cause of blindness. 250-500,000 cases are reported every year.
Toxicity of Vitamin A
Hypervitaminosis A can cause specific symptoms such as ___, ___ __ ___ skin, ____, ___, ____, ___ and ____ ___ etc.
Hypervitaminosis A can cause specific symptoms such as anorexia, dry, itchy and desquamating skin, alopecia, ataxia, headache, bone and muscular pain, etc.
