|
Vitamin
|
Functions
|
Sources |
Signs of
Deficiencies |
Signs of
Excessive Intake
|
|
A
(Retinol)
|
Essential
for growth;
Vision in dim light;
Maintenance of soft mucous tissue.
|
Milk
products;
Egg yolk:
Liver.
Can
be formed in the body from its precursor (beta-carotene),
found in:
Cabbage;
Carrots;
Green vegetables;
Lettuce
Orange/yellow vegetables;
Yellow/red fruits.
|
Deficiency
can lead to:
Stunted growth;
Night blindness;
Xerophthalmia (dry, ulcerated eyes);
Keratomalacia (dry, ulcerated eyes);
Defective dental development;
Skin Disorders.
|
Early
indications of excess vitamin A can include dry skin
and itching.
Vitamin A can be stored in the body in such large quantities
that it can become toxic. Symptoms may include: dizziness,
nausea, headaches and vomiting.
|
|
B1 (Thiamin, Aneurine)
|
Formation
of the enzyme thiamin pyrophosphate;
promotes normal metabolism, appetite, digestion, and
growth;
Brain development and function.
|
Beans;
Cereals;
Meat;
Nuts;
Peas;
Potatoes;
Yeast .
|
Moderate
deficiency may induce anxiety, depression and irritability.
Extreme
deficiency can lead to the disease "Beriberi"-
involving nerve inflammation, muscular weakness and,
in extreme cases, heart failure.
|
Excessive
doses (possibly by injection) may lead to toxic symptoms
such as:
Allergic reactions;
Disturbance of heart beat;
Nervousness;
Shaking and Swellings.
|
|
B2
(Riboflavin)
|
Production
of acetylcholine, noradrenaline, serotonin (neurotransmitters
essential to the brain);
Release of energy from carbohydrates;
Synthesis of arachidonic acid, linoleic acid and linolenic
acid (essential fatty acids);
Tissue respiration.
|
Cheese;
Eggs;
Fish;
Liver;
Milk
Pulses.
|
Deficiency
can lead to:
Ariboflavinosis;
Dizziness;
Eczema;
Insomnia;
Oversensitivity to light;
Scaly Scalp.
|
Overdose
is unlikely but extremely large doses are associated
with numbness and itching.
|
|
B6
(Pyridoxine)
|
Many
functions, including:
Maintaining healthy skin and nerves;
Formation of red blood cells;
Formation of hormones essential for functioning of the
brain;
Synthesis & breakdown of amino acids;
Resistance to disease;
Fight signs of premature ageing.
|
Many
foods including:
Fish;
Green vegetables;
Meat; Milk; Liver;
Whole-grain cereals.
|
Rare,
but can lead to:
Loss of appetite;
Anaemia;
Fatigue;
Nervousness;
Insomnia;
Memory problems;
Menstrual problems.
|
Excessive
intake can lead to poisoning and damage to the central
and peripheral nervous systems, especially the sense
of touch.
|
|
B9
(Folic Acid)
|
Synthesis
of nucleic acids;
Pre-conception & in early pregnancy folic acid is
thought to help prevent neural tube defects and other
congenital foetal malformations.
|
Green
leafy vegetables (such as spinach);
Kidneys;
Liver;
Nuts;
Whole-grains;
Yeast extract.
|
Megaloblastic
anaemia (includes several types of anaemia);
Apathy / Depression;
Dizziness;
Dull grey-looking skin.
|
|
|
B12
(Cyanocobalamin)
|
Synthesis
of nucleic acids;
Maintenance of myelin in the nervous system;
Correct functioning of Folic Acid.
|
Brewers
Yeast;
Dairy products;
Eggs;
Fish;
Liver;
Meat.
|
Affects
most body tissues, especially those containing rapidly
dividing cells;
Pernicious anaemia;
Degeneration of the nervous system (incl. loss of sensation
and poor co-ordination);
Tongue infections.
|
|
|
C
(Ascorbic Acid)
|
Antioxidant
Properties;
Maintaining healthy connective tissues;
Integrity of cell walls;
Synthesis of collagen;
Improves resistance to infections;
Promotes healthy function of phagocytes (a type of white
blood cell);
May help to reduce allergic reactions (by inhibiting
the action of histamine).
|
Citrus
Fruits;
Potatoes;
Vegetables.
|
Mild
deficiency:
Tender joints;
Soft/Bleeding gums;
Reduced immunity to diseases;
Weakness.
Extreme
Deficiency:
Scurvy.
|
Sudden
high intake of vitamin C can cause diarrhoea.
Very high dosage can lead to stomach problems in some
people.
|
|
D
|
Absorption
of calcium and phosphorous (from the intestine &
deposition of them in the bone).
Regulation of the permeability of cell membranes.
|
Liver;
Fish oils.
Ergocalciferol
(Vitamin D2)
from plant sources.
Cholecalciferol
(Vitamin D3)
is produced by the action of sunlight on
7-dehydrocholesterol, which is in the skin.
|
Deficiency
may be due to poor diet or to insufficient sunlight
and can lead to:
Decalcified
bones;
Rickets (in children);
Problems in dental development (in children);
Osteomalacia (in adults);
Muscle weakness and cramps;
Osteoporosis - if deficiency over extended period of
time.
|
Over-calcification
of the bones and teeth;
Formation of calculus stones in the kidneys and other
organs;
Hardening of arteries.
In
cases of extreme over-dose, vitamin D may lead to poisioning.
Symptoms may include:
General discomfort;
Itchy eyes and skin;
Extreme thirst;
Diarrhoea.
|
|
E
(Tocopherols and Tocotrienols)
|
Antioxidant
properties;
Muscle Development;
Production of red blood cells.
Reproductive functions.
|
Butter;
Corn and peanut oils;
Eggs;
Soya beans;
Vegetable oils;
Wheat germ;
Wholemeal Cereals.
|
|
Some
vitamin E can be safely stored in the body but excessive
doses may result in stomach problems and diarrhoea.
|
|
K
|
Needed
for formation of prothrombin by the liver - for blood
clotting.
|
Fish;
Green leafy vegetables;
Meat;
Molasses;
Nuts;
Seaweed;
Also
synthesized by bacteria in the large intestines.
|
Deficiency
may lead to:
Osteoporosis
|
Some
people with liver diseases cannot tolerate supplements
of vitamin K.
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