Vitamins: Sources, Benefits and Deficiency Diseases

A vitamin is an organic compound and a vital nutrient that an organism needs in small quantities for the proper functioning of its metabolism. 

Vitamins are essential ingredients for normal growth and development of an organism. Vitamins must be consumed periodically and in limited amount to avoid deficiency.

Vitamins are classified as either water-soluble or fat-soluble.

(i) Fat-soluble Vitamins: Vitamins A, D, E and K are fat-soluble.

(ii) Water-soluble Vitamins: Vitamins C and all the B vitamins are water-soluble.

Here is a table that depicts the type of vitamins, sources, and diseases due to vitamin deficiency. 

Name of Vitamins	Sources	Diseases caused by their deficiency
Vitamin A/ Retinol	Fish in general, liver and dairy products; orange, ripe yellow fruits, leafy vegetables, carrots, pumpkin, squash, spinach.	Skin Abnormalities, Night Blindness
Vitamin D/ Calciferol	Lichen, eggs, liver, certain fish species such as sardines, certain mushroom species such as shiitake.	Rickets in Children and osteomalacia in adults.
Vitamin E /Tocopherol	Many fruits and vegetables, nuts and seeds, and seed oils.	Deficiency is very rare; mild hemolytic anemia in newborn infants.
Vitamin K/ Phylloquinone	Leafy green vegetables such as spinach; egg yolks; liver	Impaired Blood Clotting that can cause easy bruising and bleeding diathesis.
Vitamin C/ Ascorbic Acid	Almost every fruits and vegetables contains some amount of Vitamin C.But Generally Green peppers, White Potatoes, Citrus fruits and vegetables, Strawberries, Tomatoes, Broccoli and Turnip Greens.	Scurvy, Anemia, Decreased ability to fight infections and Slow Metabolism that results in weight loss and Dryness.
Vitamin B1/ Thiamine	Pork, oatmeal, brown rice, vegetables, potatoes, liver, eggs	Beriberi, Wernicke-Korsakoff syndrome
Vitamin B2/ Riboflavin	Dairy products, bananas, green beans, asparagus	Fissures in the corner of Mouth, Tongue inflammation.
Vitamin B3/ Niacin	Meat, fish, eggs, many vegetables, mushrooms, tree nuts	Diarrhea, Skin Disease and Dementia.
Vitamin B5/ Pantothenic Acid	Meat, broccoli, avocados	Paresthesia
Vitamin B6/ Pyridoxine	Meat, vegetables, tree nuts, bananas	Anemia, Peripheral neuropathy
Vitamin B7/ Biotin	Raw egg yolk, liver, peanuts, leafy green vegetables	Dermatitis, enteritis
Vitamin B9/ Folic Acid	Leafy vegetables, pasta, bread, cereal, liver	Megaloblastic anemia and deficiency during pregnancy is associated with birth defects, such as neural tube defects.
Vitamin B12/ Cynacobalamin	Meat, poultry, fish, eggs, milk	Pernicious anemia