Vitamin Classification

Vitamin

Functions

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 (Methylcobalamin vs 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 (D3 vs D2)

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.