• Written By Ankita Sahay
  • Last Modified 25-01-2023

Vitamins: Definition, Structure, Food, Functions

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Vitamins and minerals are micronutrients that the body need to carry out a range of daily activities. However, our body does not produce these micronutrients and we must derive them from the food we eat. Vitamins A, B, C, D, E, and K are the well known Vitamins! Each vitamin performs a specific job in our body and its deficiency can lead to health problems. For instance, if your body has less than enough vitamin C, you could become anemic. Others are necessary to prevent medical problems. Vitamin A prevents night blindness. Read this entire article for detailed information on what vitamins are, what they do in our body, and which foods are their good sources.

Vitamins and Minerals

Vitamin means ‘vital for life’. For the healthy functioning of our bodies, vitamins and minerals are necessary. We need them for proper growth, to see this world properly, to form bones, muscles, skin and organs, as well as to help us fight infections. Deficiencies in certain vitamins and minerals can lead to severe problems.

The best way to ensure that we receive enough vitamins and minerals for healthy growth and development is to provide a wide variety of fresh foods from the five food groups which are: whole grain bread and cereals, green leafy vegetables, fruits, meat, fish, eggs, nuts and legumes, and dairy products such as milk, cheese and yoghurt.

Classification of Vitamins

Based on their solubility either in water or in fat, vitamins are classified into two groups:

  1. Fat soluble vitamins: They are similar to oil and do not dissolve in water. They are absorbed best when taken with high fat food and are stored in fatty tissues and livers. Hence they are called fat soluble. Vitamin A,D,E, and K are fat-soluble vitamins. They are also known as non-essential vitamins as they are synthesized by our body.
  2. Water soluble vitamins: They are readily soluble in water. Vitamin B(B1,B2,B3,B5,B6,B7, and B9) and C are water soluble. Unlike the fat soluble ones, these can’t be stored in our body. Any excess gets excreted through urine. Hence, our body needs regular supply of these two vitamins. As a result, they are also known as essential vitamins as they are not synthesized by our body.

List of Vitamins

  1. Vitamin A (Retinol)
  2. Vitamin C (Ascorbic acid)
  3. Vitamin D (Calciferols)
  4. Vitamin E (α-Tocopherol)
  5. Vitamin K
  6. Vitamin B1 (thiamine)
  7. Vitamin B2 (riboflavin)
  8. Vitamin B3 (niacin)
  9. Vitamin B6
  10. Vitamin B12 (Cyanocobalamine)

There are 1313 types of vitamins that are required by our body for proper functioning. Let’s discuss a few of them:

  1. Vitamin A (Retinol): It belongs to a class of organic compounds called carotenoids to which carotenes belong. Vitamin A is a carotene derivative, insoluble in water, but soluble in fats and oils. It is not easily destroyed on heating. It is available in cod liver oil, egg yolk, carrots, milk, butter and green vegetables.
  2. Vitamin B Complex: This consists of a number of complex substances like vitamin B1 or thiamine, vitamin B2 or riboflavin, vitamin B6 and vitamin B12 or cyanocobalamine.
    (i) Vitamin B1 (Thiamine): It is a water-soluble white crystalline compound and stable at high temperature in dry condition. Thiamine is available in milk, green vegetables, meat, egg, yeast, cereals, nuts, etc.
    (ii) Vitamin B2 (Riboflavin): It is an orange yellow water-soluble crystalline compound and quite stable to heat, but sensitive to light. This vitamin is available in milk, green vegetables, egg, liver and rice polishing.
    (iii) Vitamin B6: It consists of three similar components pyridoxal, pyridoxine and pyridoxamine and is water-soluble. It is easily destroyed by heat and ultraviolet radiation. The chief source of vitamin B6 is a cereal grain, egg yolk, meat, fish, milk and cabbage.
    (iv) Vitamin B12 (Cyanocobalamine): It is a large complex molecule that has a central cobalt atom coordinated to four nitrogen atoms. Vitamin B12 is water-soluble red crystalline solid. It is present in meat, fish, egg and curd.
  3. Vitamin C (Ascorbic acid): It is insoluble in fats and oils, but soluble in water. Vitamin C is destroyed when it comes in contact with oxygen or air even at room temperature since it undergoes reversible equilibrium. It loses effectiveness upon open storing and therefore, vitamin C tablets are kept in a sealed strip. It is present in fresh vegetables, citrus fruits (lemon, orange), tomatoes, chillies, amIa, etc.
  4. Vitamin D (Calciferol): It is a white crystalline solid soluble in fats and oils only and present in milk, egg, liver, cod liver oil etc. Morning sun rays falling on the skin forms vitamin D from the sterols present under the skin.
  5. Vitamin E (α-Tocopherol): It is also known as “antisterility” vitamin. It is a light yellow oily substance soluble in fats and oils and is present in animal and vegetable oils, cotton seed oil, maize oil, pea-nut oil, wheat germ oil, sunflower oil etc.
  6. Vitamin K: This is a mixture of vitamin K1 and K2. It is fat soluble and stable to heat. It is present in leafy vegetables, fish, egg yolk and liver.

Sources of Vitamins

The best way to ensure you get a variety of vitamins and minerals, and in the proper amounts, is to adopt a broad and balanced healthy diet. The various sources of vitamins are as follows:

  1. Vitamin A – Carrots, cod liver oil, egg yolk, milk, butter and green vegetables.
  2. Vitamin B1 – Milk, green vegetables, meat, egg, yeast, cereals, nuts, etc.
  3. Vitamin B2 – Milk, green vegetables, egg, liver and rice polishing.
  4. Vitamin B3 – Cereals, green leafy vegetables, liver, kidney.
  5. Vitamin B6 – Meat, cereals, milk, whole grains, egg.
  6. Vitamin B12 – Meat, fish, egg and curd.
  7. Vitamin C – Citrus fruits (lemon, orange), tomatoes, green chillies, amla, etc.
  8. Vitamin D – Fish, liver oil, milk, egg yolk, sunlight.
  9. Vitamin E – Cottonseed oil, Sunflower oil, wheat germ oil. Vegetable oils.
  10. Vitamin K – Green leafy vegetable, soybean oil, tomato.

Vitamin Chart

Vitamin & Sources FunctionsDeficiency Disease
A (Retinol)
Liver oil, Fish, Carrot, Milk, spinach and fruits such as Papaya and Mango
Vision and growthNight blindness, Xerophthalmia Keratinisation of Skin
B1 (Thiamine)
Yeast, Milk, Cereals, Green vegetables, Liver, Pork
Co enzyme in the form of Thiamine pyrophosphate(TPP) in glycolysisBeri – Beri(peripheral nerve damage)
B (Riboflavin)
Soybean, Green vegetable Yeast, Egg white, Milk, Liver kidney
Coenzyme in the form of FMN and FAD (Havin adenine dinucleotide) in redox reactionsCheilosis(lesions of the corner of mouth, lips and tongue)
B3 (Niacin)
Cereals, Green leafy vegetables, Liver. Kidney
Coenzyme in the form of NAD and NADP’ in redox reactions,Pellagra (photo sensitivedermatitis)
B5 (Pantothenie Acid)
Mushroom, Avocado, Egg yolk, Sunflower oil
Part of coenzyme A in carbohydrate-protein and Fat metabolismInadequate growth
B6 (Pyridoxine)
Meat, Cereals, Milk, Whole grains, Egg.
Coenzyme in amino acid metabolism, formation of Heme in HemoglobinConvulsions.
B7 (Biotin)
Liver, kidneys Milk, Egg yolk, Vegetables, Grains
Coenzyme in fatty acid BiosynthesisDepression, Hair loss muscle pain.
B9 (Folic Acid)
Feg, Meat, Beetroot Leafy vegetables, Cereals, Yeast
Nucleic acid synthesis, maturation of red blood cellsMegaloblastic anaemia
B12 (Cobalamin)
Egg, Meat, Fish
Co-enzyme In amino acid metabolism, Red blood cells maturationPerniciousAnaemia
C Ascorbic Acid
Citrus fruits (Orange, Lemon etc…), Tomato,  Amla,  leafy vegetables
Coenzyme in Antioxidantbuilding of collagenScurvy (bleeding gums)
D.Cholecalciferol D3. Ergocalciferol D2
Fish liver oil, Milk, Egg yolk, (exposure to sunlight)
Absorption and maintenance of calciumRickets (children), Osteomalacia (adults)
E (Tocopherols)
Cottonseed oil, Sunflower oil, wheat germ oil. Vegetable oils
Antioxidantmuscular dystrophy (muscular weakness) and neurological dysfunction
K (Phylloquinone and Menaquinones)
Green leafy vegetable, soybean oil. Tomato
Blood clottingIncreased blood clotting time, Haemorrhagic diseases

Importance

  1. Though vitamins are not used for energy production but are essential for growth, reproduction and maintenance.
  2. For normal colour vision, blood clotting, formation of bone and other functions of the body, we require Fat soluble vitamins.
  3. Most of the water soluble ones are very essential for metabolism of carbohydrate, lipid and amino etc. in our body where they function as coenzymes or prosthetic groups of various enzymes
  4. Some like Vitamins A and D represent steroid hormones.
  5. Deficiency of fat soluble vitamins produces night blindness, skeletal deformation, haemorrhages and haemolysis.

Functions and Deficiencies

Vitamins play a very important role in keeping us healthy. Their deficiency causes various diseases. Let’s have a brief discussion on the functions and deficiencies of vitamins:

  1. Vitamin A: Vitamin A helps in proper growth and vision.
    Deficiency of vitamin A results in the retarded growth and a change in epithelial cells. Deficiency of this vitamin causes night blindness, xerosis (in which the skin becomes dry) and xerophthalmia (in which the corneas of eyes become opaque).

2. Vitamin B1:  Vitamin B1 helps the body’s cells to convert carbohydrates into energy and metabolism. Its deficiency in diet causes loss of appetite, and a severe disease called beriberi.

3. Vitamin B2: Vitamin B2 helps in the growth of body and RBC production.Deficiency of vitamin B causes skin diseases, sore tongue and anaemia.

4. Vitamin B6: Vitamin B6 benefits the central nervous system and metabolism. Deficiency of vitamin B6 causes nervous disturbances and convulsions.

5. Vitamin B12: Vitamin B12 helps to keep the body’s nerve and blood cells healthy and helps the formation of DNA, the genetic material in all cells. Lack of this vitamin causes anaemia.

6. Vitamin C: Vitamin C protects cells and keeps them healthy. They also help in maintaining healthy skin, blood vessels, bones and cartilage. Absence of vitamin C in diet causes scurvy and pain in joints.

7. Vitamin D: Vitamin D helps in the development of bones and teeth in growing children. Its deficiency causes rickets in which the bones and legs get curved and the teeth get deformed.

8. Vitamin E: Vitamin E acts as an antioxidant, helping to protect cells from the damage caused by radicals.
Deficiency of vitamin E causes damage to the reproductive system of both males and females, and increased fragility of RBCs and muscular weakness.

9. Vitamin K: It plays a vital role in coagulation properties of blood. Its deficiency leads to profuse bleeding even from small wounds and causes disturbances in bleeding time and clotting time of blood.

Summary

It can be concluded that vitamins are needed for optimum health. It is best to get these vitamins from food sources and not depend on supplements. Though we need vitamins in small quantities, their deficiency causes many diseases. Hence, it is very important for our survival. So, now as you know the importance of vitamins in our life, make sure to include these essential nutrients daily in your diet!

FAQs on Vitamins

We have provided answers to the commonly asked questions about Vitamins below:

Q.1. What are the 3 most important vitamins?
Ans:
 The three most important vitamins are Vitamin A, Vitamin B and Vitamin C. They provide us energy, help us in proper growth and development, enhance our immune system, etc.
Q.2. What are the 13 essential vitamins?
Ans. The (13) essential vitamins that our body needs are vitamins A,C,D,E,K and the B vitamins: thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7), folate (B9) and cobalamin (B12).
Q.3. What are the 7 vitamins and minerals that our multivitamin should have?
Ans.
 7 vitamins and minerals that our multivitamin should have are Vitamin D, Calcium, Zinc, Iron, Magnesium, Folate and Vitamin B–12.
Q.4. What are the 5 most important vitamins?
Ans: 5 most important vitamins that our body needs are Vitamin B12 (Cobalamin), Vitamin B9 (Folic acid), Vitamin B6, Vitamin A and Vitamin D. They are very important for human health, growth, development, reproduction and maintenance. Their deficiencies impose serious health hazards.
Q.5. What are the 6 main vitamins?
Ans: The six main vitamins that are essential for us are: VITAMIN A, VITAMIN B, VITAMIN C, VITAMIN D, VITAMIN E, VITAMIN K.
Q.6. How can I get all my vitamins?
Ans:
 The best way by which you can get a variety of vitamins and minerals, and in sufficient amounts, is to adopt a broad and balanced healthy diet. For maintaining a healthy diet, we should focus on fruits and vegetables, whole grains, beans and legumes, low-fat protein, and dairy products and avoid food supplements or vitamin tablets unnecessarily.

Now that you have a detailed article on Vitamins from A to Z, we hope you do not face issue while preparing for the exam. If you have any query do let us know about it in the comment section below and we will get back to you soon. Visit embibe.com to learn more about important topics for school

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