Humans are not able to synthesize vitamin C due to lack of gulonolactone oxidase which is that last enzyme in the vitamin C synthetic pathway (1). The L-isomer is biologically active in humans (1). Other animals that cannot synthesize vitamin C include: primates, fruit bats, guinea pigs, and some birds (1).
Say:You may ask, why do we need Vitamin C? Does anyone know why Vitamin C is good for us? (Allow students to respond) Say:We should eat food containing Vitamin C every day. This valuable nutrient helps us grow and also aides in repairing tissues when we get hurt. It is used to make collagen, a protein that is used by our skin, bones, blood vessels, and tendons. It even helps to produce scar tissue when we get hurt or we have a cold.
Say:You may be wondering what Vitamin C’s role in within your body. Does anyone have any ideas? (Allow students to respond) Say: Vitamin C is an antioxidant, which helps protect the cells of our body from damage. It can decrease the risk for conditions such as heart disease, stroke, cancer, cataracts, and gout; just to name a few. Vitamin C can help to strengthen the immune system and prevent colds and flu. How many of you get Vitamin C in your daily diet? (Allow students to respond)
Say:Everyone should try to get the recommended amounts of Vitamin C within their daily diet. Children who are between the ages of 4 and 8 should consume 15 milligrams per day. This is equivalent to about three or four average size strawberries. Those who are between the ages of 9 and 13 should consume 25 milligrams per day. This is equal to half of a kiwi. Girls who are between the ages of 14 and 18 should try to get about 65 milligrams daily, which is about a cups worth of cantaloupe cubes. Boys within this age group have an even greater requirement of 75 milligrams per day, which is equal to an orange. Women who are 19 and older should get 75 milligrams of Vitamin C, which is roughly a half a cup of broccoli. Men who are 19 and older need to consume 90 milligrams of Vitamin C per day, which is equal to a half cup of red sweet pepper.
Say:Since Vitamin C is readily available through common foods such as orange juice, fruits and vegetables, most people today do not experience Vitamin C deficiency. Vitamin C deficiency may occur only under strict dietary restrictions or certain medical conditions. In order to know whether or not you are getting enough Vitamin C in your diet, you may want to refer to these common symptoms. Some of these signs may also be associated with other deficiencies or ailments, so you may want to consult your physician if many of them occur. Signs of deficiency include: Bleeding gums Rough and dry skin Slow healing when hurt Easy bruising Nosebleeds Weight gain Increased chance of infection
Vitamin c @ raj
The naming of vitamins began with Funk’s
isolated concentrate. The molecule present here
was called vitamin B, since it cured Beri beri
Following this, vitamins were name alphabetically:
vitamin A was discovered in 1913-1914, and then
in chronological order, vitamin C, vitamin D which
could cure rickets disease, and vitamin E which
was important to fertility.
The later discovery of a vitamin required for blood
clotting led to the naming of vitamin K where the
K denotes koagulation.
Vitamin C is ascorbic acid
The human body cannot synthesize
Vitamin C is a water soluble vitamin
In 1928 vitamin C was isolated
In 1933 its structure was determined
Vitamin C (ascorbic acid)
Antioxidant, strong reducing agent
Collagen synthesis, tissue repair,
bones & teeth, immune system, iron
Cannot be made by human body
though animals can biosynthesize
Found in citrus fruits, cruciferous
veggies, tomatoes, dark green
leafy, berries, mangos, melons
Degraded by cooking
Deficiency causes scurvy, anemia,
depression, infection, tooth/gum
problems, muscle deterioration,
fragile bones, poor wound healing
Where Does It Come From?
•Mango and many others
Vitamin C is a weak acid, called
Ascorbic acid or its salts “Ascorbate”.
It is the L-enantiomer of Ascorbic
The D-enantiomer shows no
Commercial vitamin C is often a mix
of Ascorbic acid, Sodium ascorbate
and/or other Ascorbates.
How do other nutrients interact with
vitamin C ?
•Supplemental intake of vitamin C at gram-level doses can
interfere with copper metabolism.
•Conversely, vitamin C can significantly enhance iron uptake and
metabolism, even at food-level amounts.
•Vitamin C also has important interactions with other vitamins.
Excessive intake of vitamin A, for example, is less toxic to the
body when vitamin C is readily available.
•Vitamin C is involved in the regeneration of vitamin E, and these
two vitamins appear to work together in their antioxidant effect.
VITAMIN-C IN THE WILD
•The vast majority of animals and plants are able to synthesize
vitamin C, through a sequence of enzyme driven steps, which
convert monosaccharide to vitamin C.
•In plants, this is accomplished through the conversion
of mannose or galactose to ascorbic acid.
•In some animals, glucose needed to produce ascorbate in the
liver (in mammals and perching birds) is extracted from glycogen;
ascorbate synthesis is a glycogenolysis-dependent process.
•In reptiles and birds the biosynthesis is carried out in the kidneys
Why Do We Need It?
Vitamin C helps us:
•Repair broken tissue when we get
•Make collagen – heal cuts and
The four most noted functions that vitamin C
When vitamin C is digested, it becomes a
water soluble antioxidant. Because it is in the
water soluble state, vitamin C can directly affect
the free radicals in the body. Free radicals are
molecules located in the body which are highly
reactive, and known for causing tissue damage.
They are also notoriously known for inducing
oxidative damage to the inner body, advancing
the aging process, and can also cause cancer.
2. Collagen Synthesis
Collagen is the essential part of connective tissue.
Connective tissue is needed to keep the body
together, and is the very framework of the body - the
skin, bones, teeth, blood vessels, cartilage, tendons
and ligaments - all rely on collagen.
3. The Cardiovascular System
Furthermore, vitamin C is vital for the cardiovascular
system. When the body's arteries become clogged,
there isn't enough blood flow to the heart which results
in a heart attack. Vitamin C's antioxidant properties are
absorbed into the blood stream, and can actually
repress the accumulation of arterial blood.
The Immune System
Finally, vitamin C impacts the immune system. The
immune system main operation is to protect the body
from foreign substances or toxins. For the immune
system to function correctly, vitamin C is a must. Vitamin
C is extremely important in this function because it is
involved with T-cells and white blood cells. The white
blood cells function is basically to monitor various
disease conditions. Because vitamin C boosts the white
blood cell count, an individual who consumes high doses
of vitamin C has a less likely chance of contracting
What is Its Role in The Body?
Decreasing the risk
of certain conditions
ABSORPTION & EXCRETION
Ascorbic acid is absorbed in the body by both active transport
and simple diffusion
Sodium-Dependent Active Transport—Sodium-Ascorbate CoTransporters (SVCTs) and Hexose transporters (GLUTs)—are the
two transporters required for absorption.
Ascorbate concentrations over renal re-absorption threshold
pass freely into the urine and are excreted.
At high dietary doses (corresponding to several hundred mg/
day in humans) ascorbate is accumulated in the body until the
plasma levels reach the renal resorption threshold, which is
about 1.5 mg/dL in men and 1.3 mg/dL in women.
Concentrations in the plasma larger than this value (thought
to represent body saturation) are rapidly excreted in the urine
with a half-life of about 30 minutes.
Concentrations less than this threshold amount are actively
retained by the kidneys, and the excretion half-life for the
remainder of the vitamin C store in the body thus increases
greatly, with the half-life lengthening as the body stores are
This half-life rises until it is as long as 83 days by the onset of
the first symptoms of scurvy
Recommendation for Dietary
Ages 4 to 8 : 15 mg/day
Ages 9 to 13:
Females 14 to 18: 65 mg/day
Males 14 to 18:
Females 19 < :
Males 19 < :
Some signs of deficiency:
Rough and dryskin
Slow healing when hurt
Increased chance of infection
Loss of teeth
Vitamin C Deficiency
Deficiency disease is called
Anemia – small cell type
Atherosclerotic plaques and pinpoint
Bone fragility and joint pain
Poor wound healing and frequent
Bleeding gums and loosened teeth
Muscle degeneration and pain,
hysteria, and depression
Rough skin and blotchy bruises
Diagnosis of Scurvy
Fasting blood ascorbic acid levels:
levels below 0.10 mg/dL are considered
levels of 0.10-0.19 mg/dL are considered low.
levels of 0.2 mg/dL or greater are acceptable
levels greater than 0.6 mg/dL likely rule out
White blood cell ascorbic acid concentration
is considered a more accurate measurement
of vitamin C nutritional status:
with a level of zero suggesting scurvy.
0-7 mg/dL suggesting deficiency.
8-15 mg/dL considered low.
15 mg/dL or greater is adequate vitamin C
Scurvy can be treated by eating food
containing vitamin C (such as oranges,
papaya, strawberries, lemon), tablets with
• Cardiovascular diseases
• Diabetes Mellitus
• Cancer prevention
• Common cold
• Lead toxicity
How do cooking, storage, or processing
affect vitamin C ?
Vitamin C is highly sensitive to air, water, and temperature.
About 25% of the vitamin C in vegetables can be lost simply by blanching
(boiling or steaming the food for a few minutes). This same degree of loss
occurs in the freezing and unthawing of vegetables and fruits.
Cooking of vegetables and fruits for longer periods of time (10-20 minutes)
can result in a loss of over one half the total vitamin C content.
When fruits and vegetables are canned and then reheated, only 1/3 of the
original vitamin C content may be left.
Consumption of vitamin C-rich foods in their fresh, raw form is the best way to
maximize vitamin C intake
Vitamin C Toxicity
Nausea, abdominal cramps, diarrhea, headache,
fatigue and insomnia
Hot flashes and rashes
Interference with medical tests, creating a false
positive or a false negative
Aggravation of gout symptoms, urinary tract
infections, and kidney stones
Upper level for adults: 2000 mg/day
Cease vitamin C intake & Treatment of
More Interesting Facts About Vitamin C
English sailors were called limeys because they sucked on limes to prevent
Inuit people have very few fresh fruits and vegetables, but they do not get
scurvy. That's because the traditional sea foods they eat such as seal meat
and Arctic char are high in vitamin C.
Ascorbic acid as a food additive helps preserve colours and flavours in
Vitamin C and coffee can be used to develop black and white photo film.
It is the most widely researched nutrient on the Internet.
Many people think oranges are the food highest in vitamin C, but there are
others with higher levels including red bell peppers, papaya, broccoli.