Vitamins

Vitamins are organic compounds which enhance the metabolism of proteins, carbohydrates and fats. Without vitamins the breakdown of food could not occur. Certain vitamins participate in the formation of blood cells, hormones, nervous system chemicals and genetic materials. They are classified into two groups i.e. fat-soluble and water soluble vitamins. Fat-soluble vitamins include vitamin A, D, E and K where as Water-soluble includes vitamin C and B-complex.

Sources of different vitamins and diseases caused by their deficiency

Vitamin A:
Vitamin A can be obtained in the diet foods of animal origin such as milk, eggs, fish, butter, fortified margarine, cheese and liver. In developing countries it is obtained from carotene, which is present in the green and yellow fruits and vegetables, furthermore the vegetable sources of this vitamin are sweet potatoes, pumpkin, mangoes, apricot, beet greens and dark green leafy vegetables.
Deficiency: The deficiency of vitamin leads to skin changes and to night blindness or failure of dark adaptation due to the effects of deficiency on retina.

Vitamin D:
There are only a few foods that are good sources of vitamin D. Some vitamin D is obtained from eggs, fatty fish. Fish oils, liver, butter, margarine and milk while human gets most of it from the direct sunlight. It is not found in plant foods. However, it can be obtained from vegetable margarines, some Soya milks and certain other foods which are fortified with the vitamin.
Deficiency: Deficiency of vitamin D causes rickets in children and osteomalacia in adults.

Vitamin E:
The animal origin of this vitamin includes Meats, poultry, eggs while the plant sources are vegetable oils, nuts, olives, tomatoes, papaya, kiwi fruit, blueberries and sunflower seeds.
Deficiency: It is essential for many vertebrate animals but its role in the human body has not been established. No clear evidence exist that it alleviates any specific disease.

Vitamin K:
Vitamin K is produced sufficiently in the intestine by bacteria and also provided by leafy green vegetables such as Spanich soybean, cottonseed, canola, and olive. However, the animal origin can be considered as egg yolk.
Deficiency: vitamin K deficiency results in impaired blood clotting, usually demonstrated by tests that measure clotting time. Symptoms include easy bruising and bleeding diathesis. In infants, vitamin K deficiency may result in intracranial hemorrhage.

Vitamin C:
All fruits and vegetables contain some amount of vitamin C. Foods that tend to be the highest sources of vitamin C include green peppers, citrus fruits and juices, strawberries, tomatoes, broccoli, turnip greens and other leafy greens, sweet and white potatoes, and cantaloupe. Animal sources are generally poor. Cow's milk, meat and fish contain a little amount of it.
Deficiency: The deficiency causes scurvy, anemia, decreased ability to fight infections, slow metabolism which may result in weight gain and dryness.

Vitamin B-complex:

Thiamine (B1):
Animal and plant sources include yeast, whole grains, lean pork, nuts, legumes, and thiamine-enriched cereal products.
Deficiency: A deficiency of this vitamin causes beriberi.

Riboflavin (B2):
Good sources of vitamin B2 are organ meats, nuts, cheese, eggs, milk and lean meat are great sources of riboflavin, but is also available in good quantities in green leafy vegetables, fish, legumes, whole grains, and yogurt.
Deficiency: Deficiency leads to fissures in the corners of the mouth, inflammation of the tongue showing a reddish purple coloration and skin disease.

Nicotinic acid or Niacin (B3):
Lean meats, peanuts and other legumes, and whole-grain or enriched bread and cereal products are among the best sources of niacin.
Deficiency: The deficiency state in humans causes skin disease, diarrhea, dementia, and ultimately death.

Pantothenic acid (B5):
Good sources of it include liver, kidney, eggs, and dairy products while apart from that it is present in perhaps all animal and plant tissues, as well as in many microorganisms.
Deficiency: There is no known naturally occurring deficiency state.

Pyridoxine (B6):
The best sources of B6 vitamins are liver and other organ meats, corn, whole-grain cereal, and seeds.
Deficiency: can result in central nervous system disturbances e.g. convulsions in infants, More generally the effects of deficiency include inadequate growth or weight loss and anemia due to the role of B6 in the manufacture of hemoglobin.

Biotin (B7):
Especially good sources of this widely distributed vitamin include egg yolk, kidney, liver, tomatoes, and yeast.
Deficiency: No deficiency yet is known associated with this vitamin.

Folic Acid (B9):
It occurs abundantly in green leafy vegetables, fruits like apples and oranges dried beans, avocados, sunflower seeds, and wheat germ.
Deficiency: Its Deficiency during pregnancy is associated with birth defects, such as neural tube defects

Para-aminobenzoic acid (PABA):
Para-aminobenzoic acid which is incorporated into the folic acid molecule, is sometimes listed separately as a B vitamin, although there is no evidence that it is essential to the diet of humans.

Cyanocobalamin (B12):
Neither animals nor higher plants are capable of making these vitamin B12 Nevertheless, such animal tissues as the liver, kidney, and heart of ruminants contain relatively large quantities of this vitamin. Plants are poor source of vitamin B12.
Deficiency: Its deficiency results in megaloblastic anemia.