VITAMIN, FUNCTIONS, SOURCES, CLASSIFICATION AND DEFICIENCIES

Vitamins are group of organic substances present in minute amount in natural food stuffs, vitamin is defined as any group of the organic compounds that are essential for normal growth and nutrition and are required in small quantities in the diet because they cannot be synthesized by the body. Simply put, vitamin is an organic compound required as a vital nutrient in tiny amount by an organism. This means that a substance is called a vitamin because it cannot be synthesized in sufficiency quantities by an organism and must be obtained from the diet.

Thus, the term is conditional both on the circumstances and on particular organism. For example, vitamin C (ascorbic acid) is a vitamin for human but not for most other organism, and biotin and vitamin D are required in human diet only in certain circumstances. By conversion, the term vitamins does not include other essential nutrients such as dietary minerals, essential fatty acids essential amino acid which are needed in large amount than vitamins nor those it encompass the large number of other nutrients that promote health but are otherwise required less often. Thirteen main vitamins are recognized which are:

 

Each of these vitamins has special function and source and it as shown in the table below

      1.  Vitamin A ( Retinol)

      2.  Vitamin B₁ (Thiamin)

      3.  Vitamin B₂ (Riboflavin)

      4.  Vitamin B₃ (Niacin)

      5.  Vitamin B₆ (Pyridoxin)

      6. Vitamin B₇ (Biotin)

      7.  Vitamin B₁₂ (Cobalamin)

      8. Vitamin K

      9.  Vitamin E (Tocopherol)

  10 Vitamin D (Califerol)

  11.Vitamin C (Ascorbic acid)

  12.Vitamin B₉ (Folic acid)

  13. Pantothenic Acid.

S/N	VITAMIN	FUNCTION OF VITAMIN	SOURCE
1.	Vitamin A (Retinol)	Maintenance of skin, mucus membrane, bonus teeth and hair, vision and reproduction.	Green leafy vegetable, melon, squash, yams, tomatoes, fish and liven oil etc.
2.	Vitamin D (Calciferol)	This is gotten from sunlight, the body make it from cholesterol when it is exposed to sunlight. Helps the body absorb calcium, phosphorus needed for bone growth and maintenance.	Fish, liver oils, sported seeds, mushrooms, sunflower seed etc.
3.	Vitamin B1 (Thiamin)	It is needed for nervous issue function; help to release energy from carbolic gyrate. Vitamin B1 has coenzyme from that it known as thiamine pyrophosphate (TPP or Thpp)	Brewer’s yeast, wheat,bran, word grains cereals, seeds and nuts, beans and leafy green vegetable.
4.	Vitamin B2 (Riboflavin)	It helps release energy from foods. It is essential for healthy eyes, skin, hair and nails.	Whole grains, brewer’s yeast, wheat germs, almonds sun flower seed, yeast, cooked leafy vegetable.
5.	Vitamin B3 (Niacin)	Needed for pervious and digestive system functions, essential for proteins and crab metabolisms.	Brewer portal yeast, nuts, wheat germ, rice bran, sunflower seeds, brown rice, green vegetable.
6.	Vitamin B6 (Pyridoxine)	The coenzymes form is pyridoxal phosphate. It is needed for metabolism, it helps to form red blood cells, it is important for normal reproduction process and healthy pregnancies.	Brewer yeast, bananas, avocado wheat germ/bran soya beans black strap molasses, cantoloupe.
7.	Vitamin B7 (Biotin)	It prevent hair lose, it is involved in metabolism of protein and fatty acid, it is also used in malaria treatment.	Brewer yeast unpolished rice and soya beans.
8.	Vitamin B12 (Cobalamoine)	It helps to form red blood cells and prevent anemia, it also promote growth in children. The coenzyme from is adenosine coupled to cobalamin.	Fortified brewer yeast, sunflower seeds, kelp, bananas, peanuts, raw wheat germ.
9.	Vitamin C (Ascorbic acid)	For healthy teeth gums and bones essential for proper functioning of adrenal and thyroid glands.	All fresh fruits, vegetables, rose strawberries, apples, guavas, cabbage tomatoes turnip, peppers.
10.	Folic acid	Essential for the formation of red blood cells, the healing process and aids in metabolism of proteins and contribute to normal growth.	Deep green leafy vegetable, spinach nuts, broccoli, brewer yeast.
11.	Pantothenic acid	Affect all vital body functions ward off infections and contribute to speed recovery from illness.	Royal jelly whole grains, bread, cereals, green vegetables, peanuts, crude molasses.
12.	Vitamin E	It is important in red blood cell formulation, it also prevent oxidation damage.	Raw sprouted seed nuts and grains green leafy vegetables, cold preserve liver oil.
13.	Vitamin K	Required for synthesis of certain proteins that are prerequisites for blood coagulation. It is also important for controlling binding of Calcium in bone and other tissue.	Long liver, fish meal and vegetable oils, essential for formation of normal amount of prothromin (clothing) and normal liver function.

   

 DISCOVERY OF VITAMIN

The word vitamin was derived from the word “vitamin” a combination of word made up by polish scientist (Asimir fink) from vital and amine meaning amine of life because it was suggested in 1972 that the organic micro nutrient. Factors that prevent beriberi and perhaps other similar dietary-deficient diseases might be chemical amine. This proved incorrect for the micronutrients classes and the word was shortening to vitamin.

The value of eating a certain food to maintain health was discovered long before vitamins were identified. The ancient Egyptian knew that feeding liver to a person would help “BLlNDNESS” an illness known to be cause by vitamin A deficiency. The advancement of ocean voyage during the renaissance resulted in prolong period without access to fresh fruits and vegetables and made illness from certain deficiency common among crew.

In 1942, the Scottish surgeon Jams Lind discovered that citrus fruits help prevent scurvy a particular deadly disease in which collagen is not properly formed causing poor wound healing bleeding of gums healing and death.   In 1753, Lind published his treatise on scurvy which was adopted by the British royal navy. This led to the nickname ling for sailor of that organization. Lind’s discovery was however not widely accepted and scurvy contained to plague naval screw. During the 18^th and 19^th century the use of deprivation studies allowed scientists to isolate and identify a number of vitamin, lipids from fish oil, was used to cure rackets, at and the fat soluble nutrient was called “Anthrachitic A”. This first vitamin, bio activity which cured racket, was initially called “Vitamin A” however the bio activity of this compound is now called vitamin D. in 1910, the fist vitamin complex was isolated by Japanese scientist Umetaro Suzuki, who succeeded in extracting bran and named it “Aberic Acid” and later (Omeri Zanin) he published the discovery in Japanese scientific journal when the articles was translated into German, failed to state that it was a newly discovered nutrient, a claim made in the original Japanese article and hence his discovery failed to gain publicity.

                       

   ROLE OF VITAMINS

1. it functions as antioxidant that acts as mediator for cell regulations, tissue growth and differentiation.
2. They act as catalysts that aid metabolic process.
3. They also act as co-enzymes that carry various chemical groups between enzymes thereby helping in transportation.

          CLASSIFICATIONS OF VITAMINS

Vitamins are classified based on their biological activates and not on their structure, thus each vitamin refers to a number of vitamin compounds that shows biological activities associated to their generic disruptors such as ‘vitamin A’ which include retinol and four known compounds.

IN HUMANS

Vitamins are classified as either water soluble or fat soluble. Human has thirteen (13) vitamins, four (4) fat soluble and (A, D, G, and K) and nine (9) water soluble vitamins.

Many types of water soluble vitamins are synthesis by bacteria. Fat soluble vitamins are absorbed through the intestine with the help of lipids, this is because they are more likely to accumulate n the body, they are more likely to lead to vitaminosis than water soluble vitamins.

Fat soluble vitamin is of particular importance in cystic fibrosis.

	VITAMINS	SOLUBILITY
1	Aminobenzenic acid, folic acid	water
2	Biotin	water
3	Cobalamin (B12)	water
4	Lipoic acid	water
5	Nicotinic acid (Niacin)	water
6	Pantothenic acid	water
7	Riboflavin	water
8	Thiamine(B1)	water
9	Vitamin B6, Pyridoxical, pyridoxamine group	water
10	Vitamin K	fat
11	Vitamin E	fat
12	Vitamin A	fat
13	Vitamin   c	water
14	Vitamin D	water

DEFICIENCY OF VITAMIN

The deficiency of this food nutrient is classified as primary and secondary. Primary deficiency occurs when an organism does not get sufficient amount of vitamin in its diet, while secondary deficiency may be due to overlying disorder that prevents or limits the absorption or use of the nutrient due to a life style fact or such as smoking, excessive alcohol consumption.

People who vary their diets are unlikely to develop severe primary deficiency. In contract, restrictive diet have the potential to cause prolong vitamin deficiency which may result in painful and potential deadly disease.

VITAMIN DEFICIENCIES IN HUMAN

1. Beri Beri – This is cause by Thiamine (Vitamin B₁) deficiency and is characterized bat painful polyneuritis and edema resulting from a light output from the earth.
2.  Pellagra – This is caused by lack of vitamin B₃ (Niacin), it is characterized by diarrhea, dermatitis, dementia.
3. Scurvy – This is cause by insufficiency of ascorbic acid (Vitamin C), this causes poor wound healing, and bleeding gums hemorrhage into the skin from the mucous membrane, and it can also lead to death.
4. Rickets – this is the inadequacy of vitamin D (calciferol) it  is characterized by the over production and deficient calcification of ostiod tissue with associated skeletal deformities, disturbance in growth.  Deficiencies of vitamin D, is also seen observed in  tiredness and Fatigue, cold, respiratory track infections and impaired wound healing
5. Vitamin K – the deficiency of this nutrient  include anemia, cartilage calcification and severe malformation of developing bone, it can lead to birth defect in infant such as underdeveloped nose, face bone and finger. 
6. Vitamin E (Tocophenol) – inadequacy causes hemolytic anemia in newborn, in adult it results in central nervous system irritability and increased heart failure.
7. Vitamin A( Retinol) – the lack of it causes nigt blindness, hyperkeratosis and keratomalakia.
8. Pantothenic acid -   its deficiency is characterized by diarrhea, nausea, heartburn and parathesia in newborn.
9. Vitamin B_{6 (Pyridoxine) - Lack if Pyridoxine cases  anemia, peripheral neuropathy in infant and impairment of proprioception in adult.}
10. Vitamin B_{12 - insufficiency leads to megaloblastic anemia in newborn and acne like rash in adult.}
11. Vitamin B_{7 (Biotin) – deficiency of Biotin causes dermatitis and enteritis in infant.}

 DEFINITION OF TERMS

1. Diarrhea - Abnormal frequent discharge of semi solid or fluid fecal matter from the bowel.
2. Dermatitis – Inflammation of the skin.
3. Dementia – Loss of cognitive and intellectual functions without impairment of perception of consciousness.
4. Hemorrhage – bleeding or loss of blood from rupture or vessel.
5. Calcification – Hardening of tissue as a result of precipitate or large deposits of insoluble calcium solute and sometimes magnesium, especially calcium carbonate and phosphate (hydroxyapitite).
6. Hyperkeratosis – Thickening of the horny layer of the epidermis or mucous membrane.
7. Keratomalacia –Dryness with ulceration and proliferation of the cornea of cachetic in children.
8. Proprioception – perception at sub conscious level of the movement and position of the body, especially it's limb independent of vision. This perception originates primarily from the sensory nerve terminals in the muscle, tendons and fibrous capsule.
9. Cachetic,- Malnutrition, a condition characterized by weight loss, anorexia general debility that occur as a result of chronic illness.