Name of the vitamin | Properties | Distribution | Functions | Effects of deficiency | Daily requirement |
Vitamin A | Soluble in fat solvents Insoluble in water Heat stable in absence of air. Easily destroyed on exposure to air or ultra violet rays. | Animal sources – cod liver oil, halibut liver oil, milk, butter, eggs, fishes Vegetable sources – carrots, spinach, vegetable oils, green leaves, yellow fruits e.g. mangoes, tomatoes etc. | Essential for growth It is a component of rhodopsin, hence essential for night vision. Helps in the preservation of structural integrity and the normal permeability of membranes Maintains the health and activity of epithelial tissues and glands. Prevents infection. Maintains nutrition and functions of the nervous tissue. Controls the action of the bone cells, formation and sulphation of mucopolysaccharides Helps in normal fertility. Helps in glucose synthesis by stimulating enzymes concerned. | Night blindness Xerophthalmia Keratinization of skin and mucous membrane with increased susceptibility to infections. Retardation of growth in children. Defective growth of bone and teeth. | 5,000 i.u. For adults. 6,000-8,000 i.u. For growing children and during puberty, lactation and pregnancy. |
Vitamin D | Soluble in fat solvents but insoluble in water. Heat stable | Richest sources are fish-liver oils, e.g. cod liver oil, halibut liver oil, etc. Butter, milk, eggs, liver etc. | Favour calcium and phosphorus absorption from the intestine. Related to calcium and phosphorus metabolism. Helps in the bone formation by direct action on bone cells. Helps in the development of the normal teeth. Activates the alkaline phosphatase in bone, kidney and intestine | Defective bone growth, condition known as rickets in infants and children and osteomalacia in adults. The formation of teeth becomes defective and leads to the development of dental caries. Tetany in infants. | 400-800 i.u. In growing children and during pregnancy and lactation. |
Vitamin E | Soluble in fat and fat solvents Heat stable Exist naturally as yellow oil. In foods, acts as an antioxidant and prevents vitamin A, from oxidative destruction. There are three forms of tocopherols alpha, beta and gamma. The most active form is the alpha tocopherol. | Animal sources- egg, milk, fish and muscles. Vegetable sources- vegetable seed oils, especially wheat, soyabean and corn. It has also been produced synthetically. | Tocopherols act as a cofactor in the electron transport system acting between cytochromes b and c and have got antioxidative effects and prevent oxidation. Prevent sterility. Essential for fetal development. Required for normal function of muscles. Maintains the physiological equilibrium in vascular and nervous system. | Deficiency of this vitamin may cause the death of the fetus after implantation. It is of some help in the prevention of habitual miscarriage in women. It also helps in increased metabolic rate and development of muscular dystrophy. In males its deficiency may produce atrophy of testis and changes in germinal epithelium. | Average daily intake in diet is about 15 to 20 mgm, which satisfies the requirement. |
Vitamin K | Fat-soluble. Heat stable | Vegetable sources – cabbage, spinach, alfalfa, tomato, soyabean etc. It has also been produced synthetically. | It catalyzes the formation of prothrombin and factor VII in the blood and helps in the normal coagulation of blood. It has been suggested that this vitamin acts as a coenzyme for some enzymes responsible for normal clotting reactions. It plays an important role in oxidative phosphorylation in the mitochondria. Bile salts are necessary for the absorption of vitamin K. | Defective blood coagulation due to reduction of prothrombin and factor VII in the blood causes haemorrhages. The haemorrhagic disease in the new born is believed to be due to lack of vitamin K. | Normal mixed diet supplies adequate amount. In the treatment of certain haemorrhagic diseases, 5 mgm is given either orally or by injection. |
Vitamin B1 (thiamine) | White crystalline substance. Water soluble Heat labile Unstable at high temperature and in alkaline medium. Stable in acid medium | Vegetable sources- cereals (in the husk and embryo). Pulses, nuts, yeast, beets, carrots, turnips, lettuce, cauliflower, pears, beans etc. Polished rice or white flour is poor in this vitamin. Animal sources – egg yolk contains fair amount. It has also been produced synthetically | Acts as a coenzyme of the carboxylase, which helps in the oxidative decarboxylation of pyruvic acid. It is an essential step n the oxidation of sugar in the tissues and brain. In this absence of this vitamin, pyruvic and lactic acid fail to be broken down, and accumulate in blood and tissues. Helps the enzyme system for the synthesis of fats from carbohydrates and proteins. | Beri-beri-dry, wet, cardiac or mixed type. Dry beri beri is associated with disorders of nervous system. Cardiac beriberi is associated with signs of congestive cardiac and circulatory failure In wet beri beri, polyneuritis is accompanied by oedema. In mixed beri beri there is a combination of the above conditions. Loss of appetite, atony of the gastrointestinal tract and hyperchlorhydria. In addition to these signs heart becomes weak and enlarged and oedema of the legs occurs. Cardiac failure may also occur in some patients. | About 1.8 mgm for a diet producing 3,000 calories. The requirement is increased in pregnancy, lactation, heavy muscular work, high carbohydrate diet etc. |
Vitamin B 2 (Riboflavin) | Yellow crystals Sparingly soluble in water. Heat stable in neutral and acid media. Destroyed by light. | Animal sources – milk, liver, kidney, muscle, raw egg etc. Vegetable sources – whole grains and green leafy vegetables. It has been synthetically produced. | Essential for growth. Essential for tissue oxidation In the tissues riboflavin exists as flavin mononucleotide and flavin adenine dinucleotide. These two coenzymes in combination with protein are termed flavoprotein, which have a major functional role as a number of enzyme system. It is also related to carbohydrate, fat and protein metabolism. | Keratitis, corneal opacities, vascularisation of cornea and photophobia. Loss of hair. Skin becomes dry and scaly. Arrest of growth. | 0.025 mgm of riboflavin per 1.0 gm of protein. |
Vitamin B 3 (Niacin) | White crystalline substance. Moderately soluble in water. Heat stable | Vegetable sources – dried legumes, peas, beans, tomatoes, whole wheat meal, green vegetable etc. Animal sources –meat, fish, liver, milk, eggs, yeast, kidneys, heart, etc. It has been produced synthetically. | Acts as a pellagra-preventing factor. Essential for growth. Remains as a part of at least two enzymes – NAD and NADP. They act along with dehydrogenase and take part in tissue oxidation. Helps in the formation of fats from carbohydrates. Stimulates the central nervous system. | Dermatitis, diarrhoea and dementia. Pellagra – characteristic dermatitis especially on the exposed parts of the body. The dermatitis begins with erythema resembling sunburnt areas. Gradually these areas become reddish brown, rough, scaly and keratotic. Gastro-intestinal disorders. Polyneuritis. Various forms of mental disorders. | 12-18 mgm for adult males and a little less in adult females. Requirement varies with the protein content of diet, as amino acid tryptophan gives rise to niacin. |
Vitamin B 5 (pantothenic acid) | White crystalline substance. Highly soluble in water. Heat stable | Animal sources –meat, fish, liver, milk, eggs, yeast, kidneys, heart etc. Vegetable sources – molasses, wheat, bran, peas, sweet potatoes, etc. It has been produced synthetically. | Plays a fundamental role in the metabolism as coenzyme A In combination with succinate forms active succinate and helps in the biosynthesis of haemoglobin. It also helps in the biosynthesis of fatty acids. | Various tissues affected e.g. gastrointestinal disturbances, alopecia, cornification of the skin and hypofunction of the adrenal gland. | Not exactly known Average daily diet contains 10 mgm. |
Vitamin B 6 (Pyridoxine) | It occurs in three forms, pyridoxal, pyridoxamine and pyridoxine. It is a white crystal soluble in water. Heat stable in both acidic and alkaline solutions. | Vegetable sources – germs of various grains and seeds, leafy vegetables, etc. Animal sources – liver, egg-yolk, meat, kidney, yeast etc. It has been produced synthetically. | It helps in the normal metabolism of tryptophan. Acts as a coenzyme for transaminase or aminotrasferases, decarboxylases and desulphydrases. Related to the metabolism of unsaturated fatty acids Helps in the synthesis of fats from proteins and carbohydrates. It is also called antidermatitis factor. | Peculiar dermatitis and hypochromic microcytic anaemia. Weakness of muscles and convulsive seizures. In persons suffering from pellagra and beri beri, synthetic B6 can easily cure insomnia, irritability, abdominal pain, difficulty in walking etc, which cannot be cured by other vitamins. | 0.3 mgm per day in infants and in adults 2.0 mgm daily. Sufficient in normal diet. |
Vitamin B 8 (Biotin) | Soluble in water and alcohol. Heat stable Resistant to acids and alkalis. It contains sulphur. | Widely distributed in all common articles of food – especially in yeast, egg-yolk, kidney, liver, cauliflower, peas etc. Raw egg- white contains avidin (antivitamin of biotin), which antagonizes and prevents its action. | Biotin acts as a coenzyme in CO2 fixation for the urea formation as well as for the biosynthesis of pyrimidines and fatty acids. Helps in deamination of therionine, serine and aspartic acid. Prevents dermatitis. | In man its deficiency causes peculiar dermatitis, symptoms resembling thiamine deficiency and rise of blood cholesterol. Deficiency does not occur normally but may be induced by either feeding raw egg white or intake of sulphur drugs, which interferes with the biosynthesis of this vitamin in the intestine. | Average in human 150-300 micro gram daily. Average daily diet contains sufficient amount. |
Vitamin B 9 (folic acid) | Yellow compound Slightly soluble in water and destroyed by light. | Animal sources – liver, kidney etc. Vegetable sources – widely distributed in plants and in green vegetables. | Essential for the synthesis of deoxyribonucleic acid (DNA) in the nuclei of the cells. Along with vitamin B 12 it helps in the synthesis of nucleic acid. It is also related to phospholipid metabolism and amino acid metabolism. | It deficiency may produce anaemia, leucopenia and agranulocytosis. Megaloblastic anaemia occurs especially during pregnancy. Pernicious anaemia may develop as a result of deficiency of this vitamin along with vitamin B 12 deficiency. | Exact requirement is not known. Average daily diet of adults contains about 50 microgram, which seems to be adequate. |
Vitamin B 12 | Red crystalline substance Soluble in water. | Absent in plants but present in almost all animal tissues. Rich sources are liver, kidney, eggs, beef extract, milk etc. Also found in fungus – Streptomyces griseus. Hence vitamin B12 is obtained as a byproduct in the manufacture of streptomycin. | Antipernicious anemia factor. Essential for the formation and maturation of red blood cells. Recent studies indicate that vitamin B 12 is Castle’s extrinsic factor. The intrinsic factor helps in its absorption from the intestine. Plays an essential role in the synthesis of the nucleic acid. Increases the white cell count and the platelets through its action in the bone marrow. It maintains the normal health and activity of certain parts of nervous system. Cures pernicious anaemia and also neurological manifestations of pernicious anaemia. Related to nucleoprotein, protein, carbohydrate and fat metabolism. | Pernicious or macrocytic anaemia. Brings about hyperglycaemia. Reduction in growth, nervousness and irritability is also observed. | The requirement about 1 micro gram per day. |
Vitamin C (Ascorbic acid) | White crystals Soluble in water and insoluble in fat solvents. Heat labile. Easily oxidized at 100 0C in presence of oxygen. Cannot stand cooking and canning. Destroyed by alkali and copper salts. | Vegetable sources – fresh (citrus) fruits, e.g. orange, lemon, tomato etc. Fresh vegetables e.g. cabbage, cauliflower, lettuce etc. Properly sprouted pulses, germinating grams etc. Animal sources – generally contains a negligible amount. | Regulates oxidation-reduction potential inside the cell. Related to carbohydrate metabolism. Essential for the proper functioning of the formative cells of various tissues such as fibroblast, osteoblast. Helps in the development of proteninicious matrix and deposition of calcium and phosphate in the bones. Plays a role in wound repair. In some way it is also related to the synthesis of steroid hormone. | Scurvy – increase fragility of the capillaries causing haemorrhages – under the skin, periosteum, intestine, kidney etc. The gums show erosion of the mucous membrane at their margins and due to increased fragility of the capillaries there is frequent bleeding. Malformation of bones and teeth. New dentine is not formed and the tissue becomes spongy and porous Deficiency also produces anaemia. Delayed blood clotting and clot retraction Skin eruptions Increased susceptibility to infections. Impaired healing of wounds. Disturbance in carbohydrate metabolism. Reproductive failure both in male and females. | In adults normally 75 mgm on the average, during pregnancy, lactation and adolescence 100-150 approximately. |