CHEM 181 Lecture Notes - Lecture 2: Vitamin A Deficiency, Retinitis Pigmentosa, Nyctalopia
19 Jun 2018
School
Department
Course
Professor
Video 1
Vitamin A
Discovered by Dr. Elmber Mccollum
○
Identified a fat soluble factor A that was required for
the health of rats
○
Animals that were fed butter fat and egg yolks
thrived and the one eating lard or olive oil died
○
Vitamin A is a mixture of compounds
○
Found in family foods (such as liver which is rich in
retinoids)
○
You do not have to eat animal foods to have a
sufficient vitamin A intake
Substance called pro-vitamin A which can be
converted to vitamin A in the body which is
beta carotene
§
○
Carotenoids are found in plant products
○
-
International unit
1 IU is the biological equivalent of 0.3 micrograms of
retinol or 0.6 micrograms of beta carotene
○
-
Vitamin A is good for:
Bone growth, reproduction and immune system
○
Helps the skim and mucous membranes repel
bacteria and viruses more effectively
○
Essential to healthy vision and may slow declining
retinal functioning in people with retinitis
pigmentosa
○
Night blindness is an indicator of vitamin A
insufficiency
○
-
Vitamin A deficiency is estimated to affect 1/3 of children
under the age of 5 around the world
It is estimated to claim 670,000 lives of children
under 5 every year
○
250,000-500,00 children in developing countries
become blind each year owing to a vitamin A
deficiency with the highest rate in Southeast Asia and
Africa
Can be solved by increasing intake of Vitamin A
Can eat golden rice - has a gene
extracted from daffodil and it produces
beta carotene
□
Also the golden potato □
Distributing pills in undeveloped areas
doesn't go well because they are not
used to them
□
§
○
-
Concern with beta carotene
With smokers beta carotene has been shown to
increase the risk of lung cancer (only smokers taking
large doses of beta carotene)
Thought to reduce the risk of lung cancer in
smokers
§
You cannot overdose on beta carotene if you
are not a smoker
§
○
It is possible to overdose on beta carotene (carrot
anemia - you turn orange)
○
-
Tretinoin is used to help with skin diseases
Can help with acne
○
Cannot be taken during pregnancy because it affects
the embryo in a negative way
○
-
Activity 2
What is the relationship between Vitamin A and Beta
Carotene?
Beta carotene is a precursor form of Vitamin A
○
-
Video 2
Dr. Elmer Mccollum found that vitamin D could help
prevent rickets
Rickets is a malformation of the bones
○
Came to light during the industrial revolution when
children were forced to work in mines where there
was no sunshine
Cod liver oil could be used to treat rickets
because it has vitamin D
§
○
Vitamin D is called the sunshine vitamin
○
Chemicals that are reacted on in the body by sunlight
trigger a release of vitamin D
○
Dairy products are supplemented with vitamin D to
reduce ostheoperosis and other bone issues
There is 100 IU per 350mL glass of milk
§
○
-
Many claims of benefits for vitamin D
Claim: vitamin D reduces respiratory tract infections
Research shows vitamin D supplementation
doesn’t prevent or reduce these infections
§
○
Vitamin D improves depression and mental well-
being
No significant evidence
§
○
Can prevent or treat rheumatoid arthritis
No evidence
§
○
Can treat multiple sclerosis
No evidence
§
○
Reduces morality over the period studied
Effects are not consistently statistically
significant, if there is an effect it is very small
§
○
Vitamin D reduces cancer incidence and mortality
No evidence
§
○
Vitamin D dose-more is better
Single high dose oral or injected vitamin D
increases the risk of fall or fractures
§
○
Hypdroxy-vitamin D levels should be tested routinely
Vitamin supplementation is safe and
supplement without testing is reasonable
§
When testing > NMOL/L indicates sufficiency
§
○
Vitamin D reduces falls
May reduce the number of falls among the
elderly
§
○
Vitamin D reduces fractures
Small reduction when taken at doses greater
than 800 IU/day together with 500 mg calcium
§
Around 50 individuals would have to take
vitamin D and calcium every day for 10 years to
prevent one fracture
§
○
-
Vitamin D is needed for the absorption of calcium
-
Activity 3
In the past, what was commonly given to children to
prevent rickets because it was a source of Vitamin D?
Historically, cod liver oil was given to children to
prevent rickets. One teaspoon of cod liver oil
provides approximately 427 IU of Vitamin D
○
-
Video 3
Vitamin E
Mix of 8 different compounds called tocopherol and
tocotrienol
○
Measure in IU instead of mcg and mg
○
Necessary for structural and functional maintenance
of skeletal, cardiac and smooth muscle
○
Assists in the formation of red blood cells and helps
to maintain stores of vitamins A and K, iron and
selenium
○
May have a positive effect on immune health, protect
against oxidative damage that can lead to heart
disease, have preventitive effects against cancer,
help relieve symptoms of alzheimers and prevent
diabetes related damage, particularly to the eyes
○
Daily value of vitamin E is 30 IU or 20 mg or alpha
tocopherol
Supplements usually contain 400 IU or 133 mg
§
○
-
Wilfred and Neville Shute came to the conclusion that you
need vitamin E to prevent heart disease
This was observational, we don’t know what else
they recommended to their patients
○
Little clinical research showing that vitamin E
supplements are beneficial
○
-
Vitamin K
Not one single compound
○
Group of structurally similar, fat-soluble vitamins that
the human body requires for synthesis of certain
proteins that are prerequisites for blood coagulation
and which the body also needs for controlling binding
of calcium in bones and other issues
○
Prothrombin is a protein involved in blood clotting
and is activated with the help of vitamin K as well as
osteocalcin, a protein that plays a role in
incorporating calcium into bones
Osteoporotic fractures have been linked with
low blood levels of vitamin K
§
If osteocalcin is not properly activated by
vitamin k, the calcium that it should be
delivering to the bones ends up floating around
the bloodstream and contributes to
calcification or hardening of the arteries
§
Need 2 - 3 micrograms a day, safe at larger
doses even up to 1000 micrograms
§
Vitamin K is found in plant foods such as kale
§
○
-
Activity 4
Vitamin E is a mix of eight different compounds called:
Tocopherol
○
Tocotrienol
○
-
Leafy greens are a good source of Vitamin K (true)
-
Video 4
Vitamin C
We need it because we cant synthesize it
○
If we don’t have enough vitamin C then you cant get
scurvy
Manifests in bleeding gums and sores on the
gums and body
§
○
-
Jacques Cartier
His men were afflicted with scurvy
○
The natives had a solution to this disease (brewed up
certain parts of plants to make a tea would prevent
scurvy - such as spruce needles)
○
-
James Lind
Ships physician who had conducted the first
controlled clinical trial
6 pairs of men, gave them either cider, dilute
sulfuric acid, vinegar, sea water, garlic, mustard
seed and radish root or two oranges and a
lemon
Those who had the citrus diet were cured
of scurvy
□
§
○
-
Albert Szeny Gyorgi
Isolated the antiscorbutic facture and its molecular
structure was found and named ascorbic acid by
Norman Hayworth
○
Ascorbic acid/vitamin C is one specific compound
○
-
Linus Pauling
Said that taking large doses of vitamin C could
prevent colds
○
Trials were conducted but up to 2g of vitamin C's a
day did not prevent colds
○
Some anecdotal evidence that 1g an hour for 4 hours
at the first sign of a cold could reduce severity
○
-
Activity 5
James Lind determined that citrus fruit was a cure for
scurvy in 1753, approximately how long was the time gap
between this discovery and the indentification of Vitamin C
as the primary component of citrus fruit?
175 years
○
-
Vitamin C increases the absorption of which mineral
Iron (Fe)
○
-
Video 5
B-carotene, vitamin E and possible high doses of vitamin A
supplements are harmful
-
Other antioxidants, folic acid and B vitamins, and
multivitamin and mineral supplements are ineffective for
preventing morality or morbidity due to major chronic
diseases
-
Although available evidence does not rule out small benfits
or harms or large benefits or harms in a small subgroup of
the population, supplementing the diet of well-nourished
adults with mineral or vitamin supplements had no clear
benefit and might be harmful
Vitamins should not be used for chronic disease
prevention
○
-
Non-vitamins
Companies claim that stuff is vitamins such as
calcium pangamata
○
B17 is not a vitamin
○
-
A varied diet will give you all of the vitamins that you need
-
Lecture 2 -Topic 2
Friday, January 19, 2018
11:19 AM
Video 1
Vitamin A
Discovered by Dr. Elmber Mccollum
○
Identified a fat soluble factor A that was required for
the health of rats
○
Animals that were fed butter fat and egg yolks
thrived and the one eating lard or olive oil died
○
Vitamin A is a mixture of compounds
○
Found in family foods (such as liver which is rich in
retinoids)
○
You do not have to eat animal foods to have a
sufficient vitamin A intake
Substance called pro-vitamin A which can be
converted to vitamin A in the body which is
beta carotene
§
○
Carotenoids are found in plant products
○
-
International unit
1 IU is the biological equivalent of 0.3 micrograms of
retinol or 0.6 micrograms of beta carotene
○
-
Vitamin A is good for:
Bone growth, reproduction and immune system
○
Helps the skim and mucous membranes repel
bacteria and viruses more effectively
○
Essential to healthy vision and may slow declining
retinal functioning in people with retinitis
pigmentosa
○
Night blindness is an indicator of vitamin A
insufficiency
○
-
Vitamin A deficiency is estimated to affect 1/3 of children
under the age of 5 around the world
It is estimated to claim 670,000 lives of children
under 5 every year
○
250,000-500,00 children in developing countries
become blind each year owing to a vitamin A
deficiency with the highest rate in Southeast Asia and
Africa
Can be solved by increasing intake of Vitamin A
Can eat golden rice - has a gene
extracted from daffodil and it produces
beta carotene
□
Also the golden potato
□
Distributing pills in undeveloped areas
doesn't go well because they are not
used to them
□
§
○
-
Concern with beta carotene
With smokers beta carotene has been shown to
increase the risk of lung cancer (only smokers taking
large doses of beta carotene)
Thought to reduce the risk of lung cancer in
smokers
§
You cannot overdose on beta carotene if you
are not a smoker
§
○
It is possible to overdose on beta carotene (carrot
anemia - you turn orange)
○
-
Tretinoin is used to help with skin diseases
Can help with acne
○
Cannot be taken during pregnancy because it affects
the embryo in a negative way
○
-
Activity 2
What is the relationship between Vitamin A and Beta
Carotene?
Beta carotene is a precursor form of Vitamin A
○
-
Video 2
Dr. Elmer Mccollum found that vitamin D could help
prevent rickets
Rickets is a malformation of the bones
○
Came to light during the industrial revolution when
children were forced to work in mines where there
was no sunshine
Cod liver oil could be used to treat rickets
because it has vitamin D
§
○
Vitamin D is called the sunshine vitamin
○
Chemicals that are reacted on in the body by sunlight
trigger a release of vitamin D
○
Dairy products are supplemented with vitamin D to
reduce ostheoperosis and other bone issues
There is 100 IU per 350mL glass of milk
§
○
-
Many claims of benefits for vitamin D
Claim: vitamin D reduces respiratory tract infections
Research shows vitamin D supplementation
doesn’t prevent or reduce these infections
§
○
Vitamin D improves depression and mental well-
being
No significant evidence
§
○
Can prevent or treat rheumatoid arthritis
No evidence
§
○
Can treat multiple sclerosis
No evidence
§
○
Reduces morality over the period studied
Effects are not consistently statistically
significant, if there is an effect it is very small
§
○
Vitamin D reduces cancer incidence and mortality
No evidence
§
○
Vitamin D dose-more is better
Single high dose oral or injected vitamin D
increases the risk of fall or fractures
§
○
Hypdroxy-vitamin D levels should be tested routinely
Vitamin supplementation is safe and
supplement without testing is reasonable
§
When testing > NMOL/L indicates sufficiency
§
○
Vitamin D reduces falls
May reduce the number of falls among the
elderly
§
○
Vitamin D reduces fractures
Small reduction when taken at doses greater
than 800 IU/day together with 500 mg calcium
§
Around 50 individuals would have to take
vitamin D and calcium every day for 10 years to
prevent one fracture
§
○
-
Vitamin D is needed for the absorption of calcium
-
Activity 3
In the past, what was commonly given to children to
prevent rickets because it was a source of Vitamin D?
Historically, cod liver oil was given to children to
prevent rickets. One teaspoon of cod liver oil
provides approximately 427 IU of Vitamin D
○
-
Video 3
Vitamin E
Mix of 8 different compounds called tocopherol and
tocotrienol
○
Measure in IU instead of mcg and mg
○
Necessary for structural and functional maintenance
of skeletal, cardiac and smooth muscle
○
Assists in the formation of red blood cells and helps
to maintain stores of vitamins A and K, iron and
selenium
○
May have a positive effect on immune health, protect
against oxidative damage that can lead to heart
disease, have preventitive effects against cancer,
help relieve symptoms of alzheimers and prevent
diabetes related damage, particularly to the eyes
○
Daily value of vitamin E is 30 IU or 20 mg or alpha
tocopherol
Supplements usually contain 400 IU or 133 mg
§
○
-
Wilfred and Neville Shute came to the conclusion that you
need vitamin E to prevent heart disease
This was observational, we don’t know what else
they recommended to their patients
○
Little clinical research showing that vitamin E
supplements are beneficial
○
-
Vitamin K
Not one single compound
○
Group of structurally similar, fat-soluble vitamins that
the human body requires for synthesis of certain
proteins that are prerequisites for blood coagulation
and which the body also needs for controlling binding
of calcium in bones and other issues
○
Prothrombin is a protein involved in blood clotting
and is activated with the help of vitamin K as well as
osteocalcin, a protein that plays a role in
incorporating calcium into bones
Osteoporotic fractures have been linked with
low blood levels of vitamin K
§
If osteocalcin is not properly activated by
vitamin k, the calcium that it should be
delivering to the bones ends up floating around
the bloodstream and contributes to
calcification or hardening of the arteries
§
Need 2 - 3 micrograms a day, safe at larger
doses even up to 1000 micrograms
§
Vitamin K is found in plant foods such as kale
§
○
-
Activity 4
Vitamin E is a mix of eight different compounds called:
Tocopherol
○
Tocotrienol
○
-
Leafy greens are a good source of Vitamin K (true)
-
Video 4
Vitamin C
We need it because we cant synthesize it
○
If we don’t have enough vitamin C then you cant get
scurvy
Manifests in bleeding gums and sores on the
gums and body
§
○
-
Jacques Cartier
His men were afflicted with scurvy
○
The natives had a solution to this disease (brewed up
certain parts of plants to make a tea would prevent
scurvy - such as spruce needles)
○
-
James Lind
Ships physician who had conducted the first
controlled clinical trial
6 pairs of men, gave them either cider, dilute
sulfuric acid, vinegar, sea water, garlic, mustard
seed and radish root or two oranges and a
lemon
Those who had the citrus diet were cured
of scurvy
□
§
○
-
Albert Szeny Gyorgi
Isolated the antiscorbutic facture and its molecular
structure was found and named ascorbic acid by
Norman Hayworth
○
Ascorbic acid/vitamin C is one specific compound
○
-
Linus Pauling
Said that taking large doses of vitamin C could
prevent colds
○
Trials were conducted but up to 2g of vitamin C's a
day did not prevent colds
○
Some anecdotal evidence that 1g an hour for 4 hours
at the first sign of a cold could reduce severity
○
-
Activity 5
James Lind determined that citrus fruit was a cure for
scurvy in 1753, approximately how long was the time gap
between this discovery and the indentification of Vitamin C
as the primary component of citrus fruit?
175 years
○
-
Vitamin C increases the absorption of which mineral
Iron (Fe)
○
-
Video 5
B-carotene, vitamin E and possible high doses of vitamin A
supplements are harmful
-
Other antioxidants, folic acid and B vitamins, and
multivitamin and mineral supplements are ineffective for
preventing morality or morbidity due to major chronic
diseases
-
Although available evidence does not rule out small benfits
or harms or large benefits or harms in a small subgroup of
the population, supplementing the diet of well-nourished
adults with mineral or vitamin supplements had no clear
benefit and might be harmful
Vitamins should not be used for chronic disease
prevention
○
-
Non-vitamins
Companies claim that stuff is vitamins such as
calcium pangamata
○
B17 is not a vitamin
○
-
A varied diet will give you all of the vitamins that you need
-
Lecture 2 -Topic 2
Friday, January 19, 2018 11:19 AM
11
CHEM 181 Full Course Notes
Verified Note
11 documents
Document Summary
Identified a fat soluble factor a that was required for the health of rats. Animals that were fed butter fat and egg yolks thrived and the one eating lard or olive oil died. Found in family foods (such as liver which is rich in retinoids) You do not have to eat animal foods to have a sufficient vitamin a intake. Substance called pro-vitamin a which can be converted to vitamin a in the body which is beta carotene. 1 iu is the biological equivalent of 0. 3 micrograms of retinol or 0. 6 micrograms of beta carotene. Helps the skim and mucous membranes repel bacteria and viruses more effectively. Essential to healthy vision and may slow declining retinal functioning in people with retinitis pigmentosa. Night blindness is an indicator of vitamin a insufficiency. Vitamin a deficiency is estimated to affect 1/3 of children under the age of 5 around the world.
