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What
is it?
Vitamin
C, also known as ascorbic acid, is a water-soluble vitamin,
which is essential for normal functioning of the body. Unlike
most mammals, humans do not have the ability to make their own
vitamin C and, therefore, must obtain it through their diet.
Functions
- what does it do?
Collagen.
Vitamin C is required for the
production of collagen, an important structural component of
blood vessels, tendons, ligaments, and bone. Deficiency, therefore,
leads to poor healing of wounds, fractures, pinpoint bleeding,
and bleeding gums.
Antioxidant.
Vitamin C is also
a highly effective antioxidant. Antioxidants
such as vitamin C act to protect your cells against the effects
of free
radicals,
which are potentially damaging compounds produced as by-products
of normal metabolism, as well as through exposure to
toxins and pollutants (e.g. smoking). Free radicals
can cause cell damage that may contribute to the development
of cardiovascular disease and cancers, and other diseases.
Vitamin
C may also be able to reactivate other antioxidants such as
vitamin E so that it can be resused.
Enhanced
iron absorption. Vitamin
C enhances iron absorption from non-haeme sources, which is
found primarily in fruits, vegetables, dried beans, nuts and
grain products. Therefore, increasing vitamin C-rich foods can
be beneficial to those with poor iron stores.
Immune
system. Vitamin C
is vital for the fucntion of the immune system and promotes
resistance to infection.
Requirements
- How much do we need?
|
|
| |
Recommended
Dietary Allowance*
(mg/day) |
| Life-Stage
(years) |
Males |
Females |
| 0
- 0.5 |
40a |
40a |
| 0
- 0.5 (0 - 6 months) |
50a |
50a |
| 0.5
- 1 (7 - 12 months) |
15 |
15 |
| 4
- 8 |
25 |
25 |
| 9
- 13 |
45 |
45 |
| 14
- 18 |
75 |
65 |
| Ages
19+ |
90 |
90 |
| Life-Stage
(years) |
Pregnancy |
Lactation |
| 18
and younger |
80 |
115 |
| 19
- 30 |
85 |
115 |
| Ages
31 - 50 |
85 |
120 |
*The
Recommended Dietary Allowance (RDA) is the average daily
dietary intake level that is sufficient to meet the nutrient
requirements of nearly all (97-98%) healthy individuals
in each life-stage and gender group.
aAdequate Intakes (AI) are used as no RDA is established.
The AI is
a recommended daily intake level based on observed or experimentally
determined approximations of nutrient intake by a group
of healthy people who are assumed to be maintaining an adequate
nutritional state. |
|
Sources
- Where is it found?
|
| Food
Groups |
Food
Sources |
| Nutrient
Density |
| High |
Medium |
Low |
|
| Fruit |
Citrus
fruit,Cantaloupe, Guava, Pineapple, Strawberries |
| Vegetables |
Tomatoes,
Potatoes, Cauliflower, Green vegetables |
| Bread,
cereals, rice and pasta |
Some
fortified breakfast cereals |
| Meat,
poultry, fish, dry beans, eggs, and nuts |
|
| Milk,
yoghurt and cheese |
|
| Fats,
oils, and sweets |
|
| Vitamin
C is very easily lost in processing and cooking, because
it is highly soluble (mixable) and is often discarded in
cooking water. It is easliy destroyed by air, especially
in the presence of heat and an alkaline solution. |
|
|
Deficiency
- When you have too little
Scurvy.
Severe
deficiency of vitamin C causes scurvy. Symptoms of scurvy include
bleeding and bruising easily, hair and tooth loss, joint pain
and swelling. These sypmtoms are due to the loss of the cementing
action of collagen resulting in weakening of blood vessels,
connective tissue, and bone.
Toxicity
- When you have too much
High
doses of vitamin C can lead to gastrointestinal disturbances
including diarrhoea, and iron toxicity, caused by iron overabsorption.
|
Upper
Limit+
(mg/day) |
| Life-Stage
(years) |
Males |
Females |
| 0
- 0.5 (0 - 6 months) |
ND |
ND |
| 0.5
- 1 (7 - 12 months) |
ND |
ND |
| 1
- 3 |
400 |
400 |
| 4
- 8 |
650 |
650 |
| 9
- 13 |
1200 |
1200 |
| 14
- 18 |
1800 |
1800 |
| Ages
19+ |
2000 |
2000 |
| Life-Stage
(years) |
Pregnancy |
Lactation |
| 18
and younger |
1800 |
1800 |
| 19
- 30 |
2000 |
2000 |
| Ages
31 - 50 |
2000 |
2000 |
| +Upper
Limits (UL) = The maximum level of daily nutrient intake
that is likely to pose no risk of adverse effects. Unless
otherwise specified, the UL represents total intake from
food, water, and supplements.
ND = Not
determinable due to lack of data of adverse effects in
this age group and concern with regard to lack of ability
to handle excess amounts. Source of intake should be from
food only to prevent high levels of intake. |
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