Vitamins - Types, Food Sources, Deficiency Diseases

Unlike carbohydrates, proteins and fats, vitamins do not provide calories, but they help the body to use the energy from food. Most vitamins cannot be made in our body. So they must be acquired from food. Vitamins A, D, E, K are fat soluble whereas Vitamin B complex and C are water soluble. Milk is a rich source of all vitamins except Vitamin C. Overdose of water soluble vitamin does not cause any harm but accumulation of fat soluble vitamin can be toxic. It can lead to hypervitaminosis. Even though the amount of vitamins required are small compared to other nutrients, it is very necessary. Otherwise several deficiency diseases are caused in the body. Vitamin D (in skin) and Vitamin K (in liver) can be synthesized by our body.

Different Types of Vitamins

1. Vitamin A

Vitamin A also called as Retinol is a fat soluble vitamin, needed for healthy vision, bone growth, reproduction and the immune system. The best food source for this vitamin is carrots and yellow and green vegetables. Other sources include butter, milk, fish, soya milk etc. The deficiency of Vitamin A causes Xerophthalmia (drying of cornea and ulceration), Night blindness (inability to see in the dark) and Keratinization of epithelium (dry skin and hair). Elmer Vernon McCollum (US) and Marguerite Davis (US) found vitamin A in butter and egg yolk in 1913. 

2. Vitamin B

Edward Vedder (US) and Robert Williams (US) are given credit for being the first to detect water-soluble vitamin B in 1912 as an antineuritic substance effective in curing pigeons of neuritis, a disease similar to that of beri-beri in humans. Three years after the discovery Elmer Vernon McCollum (US) and Marguerite Davis (US) labelled it 'water-soluble B', which british biochemist Jack Cecil Drummond changed to 'Vitamin B' in 1920. Vitamin B complex includes B1, B2, B3, B5, B6, B7, B9 and B12.

3. Vitamin B1

Vitamin B1 also called as Thiamine, is a water soluble vitamin helps to break down carbohydrates, fats and alcohol. The best food source for this vitamin is whole grains, yeast, egg, potatoes, pork, nuts etc. The deficiency of Vitamin B1 causes beri-beri (partial paralysis of skeletal muscles and digestive disturbances).

4. Vitamin B2

Vitamin B2 also called as Riboflavin, is a water soluble vitamin needed to extract energy from fat, protein, carbohydrate in food. Riboflavin is abundantly present in milk. So it is also known as lactoflavin. The best food source is cereals, legumes, milk, egg, meat, fish, spinach etc. The deficiency is that it is characterized by corneal ulceration and cracking of skin (especially around the lips).

5. Vitamin B3

Vitamin B3 also called as Niacin, is a water soluble vitamin involved in fat metabolism. The best food source are lean meat, milk, eggs, nuts, whole grains etc. The deficiency diseases are Pellagra (characterized by dermatitis, skin inflammation), diarrhoea and dementia (loss of intellectual function).

6. Vitamin B5

Vitamin B5 also called as pantothenic acid, is a water soluble vitamin, supports blood cell production and the conversion of food you eat into energy. The best food source are meat, milk, eggs, nuts, whole grains, and some vegetables. The deficiency diseases are fatigue, irritability, and digestive problems.

6. Vitamin B6

Vitamin B6 also called as Pyridoxine, is a water soluble vitamin. The best food source are fish, pork, eggs, spinach, cheese, cereals and bananas. The deficiency disease is Epileptiform seizures observed in children. Its symptoms include dermatitis of eyes, nose and mouth; retarded growth.

7. Vitamin B7

Vitamin B7 also called as Biotin, is a water soluble vitamin. The best food source are meat, eggs, nuts, seeds, legumes, fruits, cereals and vegetables. The deficiency diseases causes the symptoms of hair loss, brittle nails, skin rashes, and neurological issues.

8. Vitamin B9

Vitamin B9 also called as Folic Acid, is a water soluble vitamin. It is essential for the normal formation of the red blood cells, protein metabolism, growth and cell division. The best food source are yeast, green leafy vegetables, milk, cereals and nuts. The deficiency disease is megaloblastic anemia (production of abnormally large red blood cells).

9. Vitamin B12

Vitamin B12 also called as Cyanocobalamin, is a water soluble vitamin, involved in the production of red blood cells, in cell metabolism and in nerve function. The best food source are meat, eggs, milk and cheese. It is the only vitamin containing cobalt, which is absent in vegetables. The deficiency diseases are pernicious anemia and neuro-psychiatric abnormalities (memory loss, mood and personality changes).

10. Vitamin C

Vitamin C also called as Ascorbic acid, is a water soluble vitamin. It is easily destroyed by heat and light. So vitamin C rich food should be stored in cool, dark place and prepared and cooked as quickly as possible. It is essential for disease resistance and wound healing. The best food source are citrus fruits, tomatoes, cabbage, spinach, potatoes, broccoli etc. The deficiency disease is scurvy and its symptoms are swollen gums, teeth loss and bleeding gums.

11. Vitamin D

Vitamin D also called as Calciferol, is a fat soluble vitamin. It controls the absorption of calcium and phosphorous, which are essential for bone growth and development. The best food source are fish liver oils, egg yolk, milk, butter. Also synthesized in the human body by the skin under the influence of sunlight. The deficiency diseases are rickets (in infants), bones become soft (deformed) and Osteomalacia (demineralization of bones).

12. Vitamin E

Vitamin E also called as Tocopherol, is a fat soluble vitamin. It protects red blood cells and is important in reproduction. The best food sources are wheat germ, fresh nuts, seed oils, green leafy vegetables, avocados etc. Its deficiency not reported in humans, occurring only in premature babies (infertility).

13. Vitamin K

Vitamin K also called as Phylloquinones, is a fat soluble vitamin. It is involved in blood clotting. The best food sources are liver, spinach, cauliflower, green tomatoes, pork etc. Its deficiency disease is Hemorrhage (Subcutaneous and intramuscular bleedings due to delayed clotting time).