This document discusses vitamin C and its relationship to the common cold. It provides background on vitamin C, including that it is an essential water-soluble vitamin that humans must obtain from their diets as they cannot synthesize it themselves. The document reviews several studies that have examined whether vitamin C supplementation can reduce the incidence, duration, or severity of the common cold. While some studies found vitamin C may reduce incidence rates, the results on duration and severity have been mixed and significance has not been conclusively demonstrated.

1. Vitamin C and common
cold
DONE BY:
EMAN AL-ZAWWAD

2. Vitamin C
 It is an essential water-solube vitamin.
 known as Ascorbic acid and Dehydroascorbic acid
 Most animals are able to synthesize vitamin c
 However; Human, other primates, guinea pigs, fruit bats,
few birds and most fish are unable to synthesize it
 Because human are missing L-gulonolactone oxidase
enzyme , they can’t .

3. History
 Back in history, Szent-Gyorgyi (1928) and King (1932) were the
discoverers of vitamin C when scurvy disease hit people and
caused huge numbers of deaths. At that time, they found that there
is an association between scurvy and lack of vitamin C and were
awarded the Nobel Prize in 1937.
 https://www.youtube.com/watch?v=BOGO86Y_Chw

4. Sources of Vitamin C
 Because the human body cannot synthesize vitamin C, the main
source to get it from is food. There are many food sources of Vitamin
C such as papaya, oranges, asparagus, cantaloupe, cauliflower,
broccoli, Brussels sprouts, green peppers, grapefruit, kale, lemon,
and strawberries.
 Other source of vitamin C is from supplements. Vitamin C
supplements contain free ascorbic acid, calcium ascorbate, sodium
ascorbate, and ascorbyl palmitate. Moreover, vitamin C comes
from rose’s seeds capsule which is used commercially in vitamin C
supplements

5. Absorption –Transport- Storage and
Excretion of Vitamin C
 Vitamin C doesn’t need to be digested to go through the
absorption process as other macronutrients. Ascorbate goes directly
for absorption which occurs mostly in the ileum of the small intestine
across the brush border by at least two different sodium-dependent
co-transporters, designated SVCT1 and SVCT2.
 Diffusion of vitamin C occurs faster through anion channels than
Transporters

6. Cont. absorption
 The degree of vitamin C absorption is affected by the amount of
vitamin c intake and by glucose.
 When vitamin C intake increases, the absorption of vitamin C
decreases
 When there is high intracellular glucose, the absorption of ascorbat
decreases which refers to ascorbate transporter.

7. Transport of vitamin c
 vitamin C is transported in plasma and into cells. It is present in
plasma primarily as ascorbate complexed to albumin.
 Vitamin C transports into cells as dehydroascorbate acid and is
reduced to acorbate via dehydroascorbate reductase which
means using Glutathion.
 However, the content of vitamin C in cells is higher than plasma. For
instance, in white blood cells, the concentration of vitamin C is
actually 80 times higher than plasma.

8. Storage and excretion
 Vitamin C can be stored in pituitary and adrenal glands because
they have the highest concentration of vitamin C. Also, it can be
stored in white blood cells in case of chronic intake and in the eyes
and brain. On the other hand, the excess amount of vitamin C spills
directly into urine.

9. Functions
 Antioxidant capability ‘’ destroy superoxide radicals &
other free radicals before they damage DNA & lipids –
regenerate active antioxidant from vitamin E-
 Reducing agent ‘’ donate electrons to metal ions such as
ferric iron(Fe+3) and facilitate its absorption in the GI tract.
 Synthesis of neurotransmitters, collagen, carnitine &
tyrosine
 Vitamin C has a preventive effect against cancer and
cardiovascular disease
 Support the immune system

10. RDA
 Men: 90 mg/day
 Women: 75 mg/day
 pregnant women: 100 mg/day
 During lactation: 120 mg/ day
 Smokers need an additional 35 mg/ day

11. Vitamin C Intake above or below the
RDA
 Based on recommendations, deficient intake of vitamin C may lead
to a disease called scurvy, whereas higher increase intake can lead
to toxicity.

12. Vitamin c deficiency
 Scurvy
 It occurs when the daily intake of vitamin C is less than 10 milligrams and the total
body of acorbate falls to less than 300 milligrams
 it takes 45-80 days after vitamin C intake stops to occur.
 signs and symptoms: include decreased synthesis of connective tissue and collagen
everywhere in the body, pinpoint hemorrhages, easy bruising, skin discoloration,
bleeding gums and joints, loosing teeth, and impaired healing of wounds.

13. Individuals at risk
 it develops in some people who take huge amounts of vitamin C
and then suddenly stop.
 Also, it develops in alcoholism and smokers, as well as people who
have diabetes mellitus or cancers.
 People who live in poverty are at risk of having vitamin C deficiency
due to the poor diet that they have.
 Moreover, infants who only take milk may get deficiency in vitamin
c because milk is considered a very poor source of this type of
vitamin.

14. Toxicity
 It is usually not caused by eating a diet that is high in vitamin C, but
it develops from taking too many supplements at one time. For
example, taking two grams of vitamins as single dose
 Also, There are groups of people that must avoid mega-doses of
vitamin C, such as people who are prone to gout, and kidney stones
and people with disturbance of iron metabolism such as in
thalassemia, hemochromatosis, and sideroblastic anemia.
 The adverse effects of toxicity include gastrointestinal problems
such as abdominal cramps, nausea, and diarrhea.

15. Effect of Vitamin C on Common Cold
 Because vitamin C has an immune function to fight
disease to some extent, studies found vitamin c may
used to treat and prevent the common cold.
 A number of studies have found that vitamin C levels are
decreased in plasma, leucocytes and in urine during
various infections, including the common cold and
pneumonia (Harri Hemila, 2003).

16. Literature Review
 Sasazuki et al. (2006) in their study aimed to find the relationship
between Vitamin C supplementation and the common cold. They did
the study in countries that have the highest mortality from gastric
cancer which are Japan and Akita. Thus, all people who were
diagnosed as having atrophic gastritis were included in the population
of the study. The research included 144 subjects which were assigned to
get 50 mg of Vitamin C whereas 61 subjects which were assigned to
receive 500 mg of Vitamin C. Researchers found that the incidences of
the common cold were 21.3 % for the low dose and 17.1% for the high-
dose groups. In addition, the reduction of severity and duration of the
common cold were not really significant. Sasazuki et al. (2006)
concluded that the Vitamin C supplementation is able to reduce the
incidence, but it does not have an extreme impact on the duration or
severity of common cold.

17. Cont.
 Another study was conducted by Milne (2008) was aimed to find
whether oral doses of 0.2 g/day or more of Vitamin C reduces the
incidence, duration, or severity of the common cold if it used as
continuous prophylaxis, or after the onset of symptoms. In this study,
All ages and genders were included.
 Milne (2008) concluded that Vitamin C supplementation when it is
taken regularly can reduces duration and severity of common cold
during the prophylactic supplementation period and therapeutic
period for ordinary population, but it has no effect on incidence.
Vitamin C decreases incidence only for athletic population who are
under severe acute physical stress.

18. References
 Gropper, S., Smith, J., & Groff, J. (2009). Chapter 9: The Water-Soluble Vitamins. Advanced
nutrition and human metabolism (5th ed., pp. 309-372). Belmont: Wadsworth/Cengage
Learning
 Mechanisms of symptoms of common cold and flu. (2009). In R. Eccles & O.
Weber (Eds.),Common cold (pp. 23-45). Basel: Birkhäuser.
 Milne, A. (2008). Summary of ‘Vitamin C for preventing and treating the
common cold’. EVIDENCE-BASED CHILD HEALTH: A COCHRANE REVIEW
JOURNAL, 3(3), 721-722.
 Sasazuki, S., Sasaki, S., Tsubono, Y., Okubo, S., Hayashi, M., & Tsugane, S. (2006). Effect Of
Vitamin C On Common Cold: Randomized Controlled Trial. European Journal of Clinical
Nutrition, 60(1), 9-17. Retrieved from
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&it=r&p=HRCA&sw=w&asid=e0794b1611688458a1f73927e60d1086