In the early years of 20th century, the focus of nutritionists shifted from calories to ‘Protective foods’ that were found to prevent certain deficiency states and that led to discovery of Vitamin B1 or Thiamin – the first vitamin to be discovered. Polish-American biochemist Casimir Funk coined a term ‘Vitamine’ (Vital amine) in 1911 and later it was cropped to make ‘Vitamin’. Now vitamins have become such an integrated part of human life that pharmaceutical companies are making billions by selling them. Let’s look at their real worth.
What are vitamins?
Vitamins are the essential micro-nutrients, ‘essential’ because they are important for various bodily functions but are not synthesized in the body- (at least not adequately) and hence need to be supplied through food or supplements and ‘micro-nutrients’ because they are required in small quantity measurable in micrograms or milligrams. They are organic compounds present naturally in various plant and animal food sources and they are also produced synthetically in laboratory. What are fat-soluble and water-soluble vitamins?Fat-soluble vitamins dissolve in fat and water-soluble ones dissolve in water. Vitamins A, D, E and K are fat-soluble whereas Vit.C and Vit.B-complex are water-soluble. During the cooking processes, water-soluble vitamins are much more likely to be destroyed by heat or by dissolving in water. What is their role in body?
Ø Vitamin A is important in growth, immunity, vision and integrity of skin and other mucus membranes in body. Ø Vitamin D plays an important role in calcium and phosphorus metabolism in the body and is important for strengthening of bones and teeth. Ø Vitamin E is an anti-oxidant and prevents tissue damage. Ø Vitamin K is essential in blood clotting system. Ø Vitamin C is needed for formation of healthy connective tissue essential in growth and repair of bones, teeth and blood vessels. It is needed in wound healing, general immunity and improves iron absorption. Ø Folic acid is important for red cell formation and normal development of embryo. Ø Vitamin B12 plays a role in red blood cell formation and in function of nervous system. Ø Vitamins B1, B2, B3, B5, B6 and Biotin all play important role in various metabolic processes in body ensuring proper energy production and storage. They are needed for healthy functioning of nervous system. What are the important vitamin deficiency states?
Ø Vitamin A deficiency leads to dryness of skin (Xerosis) and dryness of eye membranes (Xerophthalmia). It can lead to night blindness. Ø Vitamin D deficiency causes weak bones and teeth resulting into Rickets. Ø Vitamin E deficiency causes a hemolytic anemia. Ø Vitamin K deficiency can cause Haemorrhagic disease of newborn. Ø Vitamin C deficiency can lead to Scurvy with painful bones and easy bruising. Ø Folic acid and Vit.B12 deficiency can each lead to megaloblastic anemia. Ø Vitamin B1 (Thiamin) deficiency can cause Beriberi, which affects nerves and heart. Ø Vitamin B3 (Niacin) deficiency can cause Pellagra leading to diarrhea, dermatitis and altered mental state. What is Hyper-vitaminosis?Hypervitaminosis is a state arising out of excessive consumption of vitamins. Fat soluble vitamins- Vit.A and Vit.D are the ones that are important in this regard. Hypervitaminosis A can be acute or chronic. In acute state, severe headache, nausea, vomiting and double vision occur because of increased intra-cranial pressure (a condition called ‘Pseudotumor cerebri’). In chronic state, anorexia, weight loss, hair loss and bone changes can take place.
Hypervitaminosis D can cause increased calcium level leading to harmful effects on heart, kidneys and eyes. It also can cause pseudotumor cerebri. What are the rich food sources of vitamins?
Ø Vit.A: Full cream milk, milk products, fortified margarine, oily fish, green and yellow vegetables. Ø Vit.D: Full-cream milk, butter, fortified margarine, oily fish. (Body can produce and store Vit.D on exposure to sunlight.) Ø Vit.E: Cereal germs, oil seeds, leafy vegetables, animal organs, milk, butter. Ø Vit.K: Green vegetables, potatoes, tomatoes, liver oils. Ø Vit. C: Fresh fruits (especially citrus fruits), green leafy vegetables, milk. Ø Folic acid: Green leafy vegetables, roots and pulses, cereals, fruits, milk. Ø Vit.B12: Dairy products, eggs, meat, fish. Not found in vegetable sources. Ø Other B-complex vitamins: Dairy products, vegetables, fruits, cereals, yeast extract. What is mega-dose vitamin therapy?
Taking large doses of vitamins –especially that of Vit.C and Vit.E has been advocated by some authorities citing their benefits in preventing many conditions like cancer, heart disease and aging. None of these theories have been conclusively proved and remain experimental as of today. Mega-dose of Vit.A in measles and that Vit.D in Vitamin D-deficiency rickets are found to be useful. Do vitamins improve appetite?
Although vitamins are the favourite prescriptions that parents like to ask and doctors like to write for the treatment of reduced appetite, they don’t really play any role in that respect. Their importance in such condition is to prevent any deficiency arising out of the inadequacy of diet. Daily requirement chart: VITAMIN
| INFANTS
| CHILDREN
| ADULTS
|
|
|
|
| VIT. A (MICROGRAMS)
| 375
| 700
| 1200
| VIT.D (MICROGRAMS)
| 5
| 15
| 5
| VIT.E (MICROGRAMS)
| 4
| 7
| 10
| VIT.K (MILLIGRAMS)
| 10
| 30
| 60
| VIT.C (MILLIGRAMS)
| 35
| 45
| 60
| FOLATES (MICROGRAMS)
| 80
| 200-400
| 400
| VIT.B1-THIAMIN
(MILLIGRAMS)
| 0.3
| 0.6
| 1.2
| VIT.B2-RIBOFLAVIN (MILLIGRAMS)
| 0.4
| 0.6-1.1
| 1.2
| VIT.B3 – NIACIN
(MILLIGRAMS)
| 4
| 8-14
| 16
| VIT.B5 – PANTOTHENIC ACID (MILLIGRAMS)
| 1.8
| 3
| 6
| VIT.B6 – PYRIDOXINE (MICROGRAMS)
| 0.3
| 0.6-1.5
| 1.7
| VIT.B12 – COBALAMIN (MICROGRAMS)
| 0.5
| 1.2
| 2.4
|
(Note: These values are based on 1997 recommendations of US National Academy of Sciences. Conditions like age, sex, pregnancy and lactation affect these values in adulthood.)
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