Nutrients - Vitamins

Vitamins are a group of organic substances that are required in minute quantities in the diet in order to maintain good health. A lack of a  particular vitamin results in a deficiency disease. There are six vitamin groups such as Vitamin A, B, C, D, E , K and P. 

Vitamins are classified as Fat soluble vitamins and Water soluble vitamins. Fat soluble vitamins include (1)Vitamin A and Carotene ( Provitamin A), (2) Vitamin D - Vitamin D2 (Calciferol, artificial vitamin D) and  Vitamin D3 ( Irradiated dehydrocholesterol), Natural Vitamin D), (3) Vitamin E and (4) Vitamin K.  

Water soluble vitamins include (1) Vitamin B complex - Vitamin B1( thiamine, aneurin), Riboflavin, nicotinic acid and Nicotinamide, Vitamin B6 (Pyridoxin) , Pantotnenic acid, folic acid, Biotin, Choline, P- Amino benzoic acid, Inositol and Vitamin B12 (2) Vitamin C (3) Vitamin P 

Minerals are chemical substances such as calcium, sodium, iron and potassium which act as components of main body structures like bones, teeth, blood and soft tissues. They are found in green vegetables, fruits, cereals, nuts, seeds diary products, eggs and fish. A deficiency of minerals can lead to particular conditions. For example deficiency of iron can lead to some forms of anemia.

Vitamins and minerals doesn't directly provide energy but they contribute to nutrition by allowing chemical reactions to occur normally through out the body. These reactions known as metabolism are responsible for certain functions like converting fats and carbohydrates into energy and utilizing proteins to repair injured tissues by vitamins and the production of blood and bone and transmission of nerve impulses by minerals.

Fat Soluble Vitamins

Vitamin A (retinol) is needed for the normal bone formation, maintenance of skin and tissues. The main sources of vitamin A are fish liver oils, liver of animals, diary products like butter, ghee, milk and eggs.  Green leafy vegetables, red palm oil, carrot, pumpkin  and ripe mango are important sources of carotene. Carotene (Provitamin A) is converted to vitamin A in the intestinal walls. A deficiency causes night blindness and possible total loss of vision, and causes the tissues to be keratinised. Adults and older children require 750mg of Vitamin A and 3000 mg of Carotene daily. But excess of Vitamin A is toxic i.e children receiving daily large doses 30,000 to 1,50,000may have headache, a dry itching sin, swelling and brittleness of bones. 

Vitamin D (Calciferol) controls  calcium levels in the blood, prompting increased uptake of the minerals from the digestion of food and hence making it available for  bone growth and repair. The deficiency of Vitamin D causes bone deformities. The dietary sources are fish liver oils (of cod, halibut, shark), fat fish ( sardine, salmon, Herring), egg yolk and dairy products( butter, ghee, milk). D3 (Cholecalciferol) can be formed in the skin  from the sun's rays. The daily requirement of Vitamin D for adults is about 200 I.U  and for infants, children, pregnant and nursing women it is 400 I.U.  An excess can produce toxic symptoms like loss of appetite, nausea, vomiting etc

Vitamin E comprises several compounds that are essential for the maintenance of cell membranes. It is essential for normal reproduction. The main sources are wheat germ oil, corn germ oil, vegetable oils ( Soy bean, cottonseed, sunflower, ground nut, mustard, coconut etc) cereals and eggs. Daily requirements are 25-30 mg for adults and 10-20mg for children.

Vitamin K or Phylloquinone, a Compound form,  act as a coenzyme in protein synthesis in blood clotting. Inadequate intake of vitamin K by the mother may cause hemorrhagic disease of the new born. The deficiency is rare but if it occurs, the result may be severe bleeding. Green leafy vegetables ( spinach, cabbage, kale), vegetables (cauliflower, soybean, carrots, potatoes), wheat bran, wheat germ etc are good dietary sources. 

Water soluble Vitamins

Vitamin B Complex includes B1 (Thiamine), B2 (Riboflavin) B3 (niacin or Nicotinic acid), B6 (Pyroxidine ), Pantotnenic acid, folic acid, Biotin, Choline, P- Amino benzoic acid, Inositol, B12 (Cyanocobalamin) etc. Vitamin B is required for the manufacture of Red blood cells, enzyme activity and for amino acid metabolism.  It is essential to maintain the nerves in healthy condition, normal functioning of the skin and intestinal tract. 

The main sources of B1 are dried yeast, rice polishings, wheat germ, whole cereals, liver and is found in minimal quantities in fruits, vegetables, milk etc.; Rich sources of B2, B3, B6, Pntothenic acid, Folic acid , Biotin include liver, dried east, whole and skim milk powders, peanut, rice polishings etc, good sources include meat, fish, eggs, legumes (pulses) and dhals, leafy vegetables, whole cereals etc. Vitamin B12 is present only in foods of animal origin. Liver is the richest source and meat, fish, kidney, brain and eggs are good sources. A deficiency in Vitamin B1, causes 'Beri Beri' characterized by numbness, muscle wasting and difficulty in walking; deficiency in vitamin B3 causes 'Pellagra', characterized by dermatitis (skin ailment) in the hands, feet and neck, diarrhea and dementia; while  a lack of some of the others can result in Anemia and deterioration of the nervous system. 

Vitamin C (ascorbic acid)  is needed for maintenance  of cell walls and connective tissue including blood vessels and tendons. It helps in the rapid healing of wounds and in the absorption of iron. A deficiency causes fragility of skin, blood vessels and tendons characteristics of the disease known as Scurvy. General weakness, spongy bleeding gums, loose teeth, swollen tender joints, hemorrhages in various tissues and under the skin are symptoms. Main sources of vitamin C are citrus fruits and green leafy vegetables (drumstick leaves, coriander leaves, cabbage). Gooseberry and Guava are rich sources. Orange, pineapple, lime juice, cashew fruit, ripe mango, papaya and tomato are good sources. Daily requirements are adults 50 mg and children, between 30-50 mg.

Vitamin P ( Bioflavonoids) is essential along with ascorbic acid (Vitamin C) in preventing capillary fragility. A deficiency causes decreased capillary (vessel) resistance leading to bleeding, accompanied by pain across the shoulders and in the legs. The main sources are fresh fruits  (orange, apple, blackberry, cherry, plum) and vegetables (spinach, tomato, lettuce, cabbage, carrot, cauliflower, pea etc.).