Chapter 4 :- Micro Nutrients

 (A.) Vitamins:-

Definition and Classification (water and fats soluble vitamins) :-

Definition:- Vitamins is the term used for a group of potent organic compounds other than proteins,carbohydrates, and fats which occur in minute quantities in food and which are essential for some specific body functions such as regulation, maintenance, growth, and protection. Many of them cannot be synthesized, at least in adequate amounts, by the body and must be obtained from the diet.

Classification:-

• Fat-soluble vitamins:- The fat-soluble vitamins are vitamins A,D,E,and K. They require fat for their absorption and can be stored in the body. If their intake is poor, but body stores are ample, deficiency symptoms will not be seen immediately. 
• Water-soluble vitamins:- The water-soluble vitamins are B-complex vitamins and vitamin C. Being water soluble, they are easily absorbed and the excess consumed is excreted in the urine. They are not stored in the body. 

Food sources, functions and significance of:-

(1.)  Fat soluble vitamins (Vitamins A,D,E,K):-

Vitamin A :- vitamin A; includes retinol, retinal, retinyl esters, and retinoic acid and is also referred to as “preformed” vitamin A. Beta carotene can easily be converted to vitamin A as needed.

• Function: Essential for vision Lycopene may lower prostate cancer risk. Keeps tissues and skin healthy. Plays an important role in bone growth and the immune system. Diets rich in the carotenoids alpha-carotene and lycopene seem to lower lung cancer risk. Carotenoids act as antioxidants. Foods rich in the carotenoids lutein and zeaxanthin may protect against cataracts.
• Food Sources: Sources of retinoids: beef liver, eggs, shrimp, fish, fortified milk, butter, cheddar cheese, Swiss cheese
  Sources of beta carotene: sweet potatoes, carrots, pumpkins, squash, spinach, mangoes, turnip greens, and almost all green vegetables.
• Deficiency: Deficiency of Vitamin A called Night Blindness.

Calciferol (vitamin D):- 

• Function: It helps to maintain normal blood levels of calcium and phosphorus, which strengthens bones. It helps in the formation of teeth and bones. Supplements can reduce the number of non-spinal fractures.
• Food Sources: Fortified milk or margarine, fortified cereals, fatty fish
• Deficiency: Deficiency can result in weakened bones.

Alpha-Tocopherol (vitamin E):-

• Function: Acts as an antioxidant, neutralizing unstable molecule that can damage cells. Protects vitamin A and certain lipids from damage. Diets rich in vitamin E may help prevent Alzheimer’s disease. Cures muscle, heart and skin diseases, burns.
• Food Sources: Wide variety of foods, including vegetable oils, salad dressings, and margarine made with vegetable oils, wheat germ, leafy green vegetables, whole grains, nuts
• Deficiency: Muscle weakness, Coordination, and walking difficulties, Vision deterioration

Phylloquinone, Menadione (vitamin K):-

• Function: Activates proteins and calcium essential to blood clotting. May help prevent hip fractures. Vitamin K1 in plants has a saturated side chain. Vitamin K2 in animals has a long unsaturated side chain. Vitamin K2 is needed for the synthesis of zymogens for blood clotting. Higher need by newborns, people with liver diseases, or fat malabsorption.
• Food Sources: Cabbage, liver, eggs, milk, spinach, broccoli, sprouts, kale, collards, and other green vegetables
• Deficiency: Vitamin K deficiency is much more common in infants. In infants, the condition is called VKDB, for vitamin K deficiency bleeding.

Water soluble vitamins (Vitamin C, Thiamine, Riboflavin, Niacin, Cyanocobalamin, Folic acid) :-

Thiamin (vitamin B1) :-

• Function: It helps to convert food into energy. Needed for healthy skin, hair, muscles, and brain and is critical for nerve function.
• Food Sources: Pork chops, brown rice, ham, soymilk, watermelons, acorn squash
• Deficiency: Deficiency of thiamin results in beriberi and its symptoms are fatigue, weight loss, and nerve degeneration.

Riboflavin (vitamin B2) :-

• Function: It helps to convert food into energy. Needed for healthy skin, hair, blood, and brain.
• Food Sources: Milk, eggs, yogurt, cheese, meats, green leafy vegetables, whole, and enriched grains and cereals
• Deficiency: riboflavin deficiency also known as ariboflavinosis, include skin disorders, hyperemia (excess blood) and edema of the mouth and throat, angular stomatitis (lesions at the corners of the mouth), cheilosis (swollen, cracked lips), hair loss, reproductive problems, sore throat, itchy and red eyes, and degeneration of the liver and nervous system.

Niacin (vitamin B3, nicotinic acid) :-

• Function: It helps to convert food into energy. Essential for healthy skin, blood cells, brain, and nervous system.
• Food Sources: Meat, poultry, fish, fortified and whole grains, mushrooms, potatoes, peanut butter
• Deficiency: Deficiency of niacin can result in dermatitis, muscle fatigue and loss of appetite.

Pantothenic Acid (vitamin B5) :-

• Function: It helps to convert food into energy. It helps in making lipids (fats), neurotransmitters, steroid hormones, and hemoglobin.
• Food Sources: Wide variety of nutritious foods, including chicken, egg yolk, whole grains, broccoli, mushrooms, avocados, tomato products.
• Deficiency: Its deficiency may cause fatigue, retarded growth, insomnia, depression.

Pyridoxine (vitamin B6) :-

• Function: Aids in lowering homocysteine levels and may reduce the risk of heart disease. It helps in converting tryptophan to niacin and serotonin, a neurotransmitter that plays key roles in sleep, appetite, and moods. Helps in making red blood cells Influence cognitive abilities and immune function.
• Food Sources: Meat, fish, poultry, legumes, tofu and other soy products, potatoes, noncitrus fruits such as bananas and watermelons
• Deficiency: Vitamin B6 deficiency can result in microcytic anemia, electroencephalographic abnormalities, dermatitis with cheilosis (scaling on the lips and cracks at the corners of the mouth) and glossitis (swollen tongue).

Cobalamin (vitamin B12) :-

• Function: Aids in lowering homocysteine levels and may lower the risk of heart disease. Assists in making new cells and breaking down some fatty acids and amino acids. Protects nerve cells and encourages their normal growth Helps make red blood cells and DNA.
• Food Sources: Meat, poultry, fish, milk, cheese, eggs, fortified cereals, fortified soymilk
• Deficiency: The deficiency of cobalamin leads to pernicious anemia and nerve damage.

Biotin :-

• Function: It helps to convert food into energy and synthesize glucose. It helps in making and breaking down some fatty acids. Needed for healthy bones and hair.
• Food Sources: Many foods, including whole grains, organ meats, egg yolks, soybeans, and fish
• Deficiency: Biotin deficiency includes hair loss (alopecia) and a scaly red rash around the eyes, nose, mouth, and genital area. Neurologic symptoms in adults have included depression, lethargy, hallucinations, numbness, and tingling of the extremities, ataxia, and seizures.

Folic Acid (vitamin B9) :-

• Function: It is vital for new cell creation, helps to prevent brain and spine birth defects when taken early in pregnancy; it should be taken regularly by all women of child-bearing age since women may not know they are pregnant in the first weeks of pregnancy. Can lower levels of homocysteine and may reduce heart disease risk May reduce the risk for colon cancer. Offsets breast cancer risk among women who consume alcohol.
• Food Sources: Fortified grains and cereals, asparagus, okra, spinach, turnip greens, broccoli, legumes like black-eyed peas and chickpeas, orange juice, tomato juice
• Deficiency: It causes Folate-deficiency anemia. Folate-deficiency anemia is the lack of folic acid in the blood.

Ascorbic Acid (vitamin C) :-

• Function: Foods rich in vitamin C may lower the risk for some cancers, including those of the mouth, esophagus, stomach, and breast. Long-term use of supplemental vitamin C may protect against cataracts. It helps to make collagen, a connective tissue that knits together wounds and supports blood vessel walls. It also helps to make the neurotransmitters serotonin and norepinephrine Acts as an antioxidant, neutralizing unstable molecules that can damage cells. Bolsters the immune system.
• Food Sources: Fruits and fruit juices (especially citrus), potatoes, broccoli, bell peppers, spinach, strawberries, tomatoes, Brussels sprouts,guava,amla
• Deficiency: Vitamin C deficiency called Scurvy.
  Excess of Vitamin C can cause Diarrhea, Nausea, Vomiting.

(B.) Minerals:-

Definition and Classification (major and minor) :-

Mineral elements are inorganic substances found in the body tissues and fluids. They occur in foods as salts, e.g., sodium chloride, calcium phosphate, and ferrous sulphate. They constitute 4 percent of our body weight. 

                 Unlike carbohydrates, fats, and proteins, they do not furnish energy. They have many functions in our body such as tissue building and regulation of body fluids. Like vitamins, they are required in small quantities and are vital to the body. They should be supplied daily as they are excreted through the kidney, the bowel,and the skin.

Minerals are present in the body 

1. As components of organic compounds, e.g., hemoglobin contains iron and thyroxine contains iodine. 
2. As inorganic compounds, e.g., calcium phosphate in the bones. 
3. As free ions in every cell in the body. 
4. In all body fluids. 

Sodium is the main electrolyte in the extracellular fluid, and potassium is the main electrolyte in the intracellular fluid. 

     The mineral elements are not destroyed by heat, oxidation, acid, or alkali. Since they are soluble in water, some loss occurs due to leaching when cooking water is discarded. 

Definition:- Minerals are inorganic elements required by the body in varying amounts to carry out various body functions. They remain largely as ash when plant and animal tissues are ignited.

Classification of Minerals:-

Minerals may be classified into three groups:

1. Major Minerals or macrominerals - Seven minerals are required in large amounts of over 100 mg/day ,e.g., calcium, phosphorus, sodium, chlorine, potassium, magnesium, and sulphur. 
2. Minor Minerals- These are required in small quantities, less than 100 mg/day ,e.g. iron and manganese. 
3. Trace Elements - A few micrograms to a few milligrams are required per day, e.g., iodine, fluorine,zinc,and molybdenum. 

Food Sources, functions and significance of:-

Calcium:-

Functions:- 

1. 99 % calcium is in the form of Ca3PO4 to give hardness to bones to hold body weight. 
2. Catalyzes clotting of blood 
3. For contraction and relaxation of muscles 

Food Sources:-Milk and milk products such as curds,butter milk,and cheese; green leafy vegetables; small fish; ragi; paan ; (betal leaf with lime)

Deficiency:-

1. Rickets in children 
2. Osteomalacia in adults (refer vitamin D)
3. Osteoporosis 
4. Tetany

Iron:-

Functions:-

1. Component of hemoglobin necessary for carrying O2.
2. Part of enzyme structure 

Food Sources:- Liver, organ meat,shellfish, lean meat, egg yolk, peaches, apricots, green leafy vegetables, wholegrain and enriched cereals, jaggery, legumes, poha,iron cooking utensils 

Deficiency:-

1. Hypochromic anemia, cells are pale
2. General fatigue 
3. Breathlessness on exertion 
4. Headache 
5. Oedema 
6. Pallor
7. Hemoglobin 5-9 g/100 ml
8. Spoon-shaped nails

Sodium:-

Functions:-

1. Maintaining fluid balance and normal osmotic pressure between intracellular and extracellular compartments. 
2. It maintains normal irritability of nerves and helps in muscle contraction. 
3. Regulates the alkalinity and acidity of body fluids along with the mineral chloride. 
4. Regulates cell permeability or passage of substances into and out of the cell.

Food Sources:- Milk ,egg white, meat,poultry, green leafy vegetables, bengal gram dal, beetroot, and knolkhol.

Deficiency:- A deficiency is seen in people engaged in heavy physical activities such as farm and mine workers and in athletes. It may also occur in cases of severe vomiting and diarrhoea.

It results in weakness, giddiness, nausea,and muscle cramps. It can be treated by adding salt to water or lime juice and if this is not retained, intravenous saline could be given. 

Iodine:-

Functions:-

1. As a constituent of thyroid hormone thyroxine it regulates rate of oxidation in the cell and determines rate of metabolism. 

Food sources:- Saltwater fish, shellfish, iodine content of eggs, meat,dairy products depend on iodine content of diet of animal, fortification of salt with potassium iodate

Deficiency:-

1. Goitre- an enlargement of the thyroid gland in an attempt to secrete more thyroxine 
2. Cretinism in infants born to thyroxine deficient women 
3. Low BMR, muscular flabbiness,dry skin,thick lips,mental and skeletal retardation. Deficiency is more in females 

Fluorine:-

Functions:-

1. Fluoride along with calcium forms tooth enamel which is more resistant to decay
2. Maintains bone structure 

Food sources:- Food,water,milk,egg,fish, fluoridated water, topical applications of stannous fluoride by dentists; 1 ppm or 1 mg per litre is the ideal level of fluoride in drinking water 

Deficiency:- Deficiency causes

      a) tooth decay 

      b) osteoporosis 

Excess (more than 1.5 ppm) causes 

      a) mottled teeth, teeth are discoloured ,have a chalky white appearance (dental fluorosis)

      b) skeletal fluorosis

Key Terms:-

• Electrolyte:- An element or compound which dissociates, when in solution, into ions. 
• Oxalic acid:- An organic acid present in green leafy vegetables and cocoa.
• Phytic acid :- An organic acid present in outer layers of cereals which combines with calcium forming insoluble calcium phytate.
• Anaemia:- A condition in which number of RBCs or hemoglobin content of blood is reduced. 
• Antioxidant:- A substance naturally present or added to a product to prevent its breakdown by oxygen. 
• Carotene:- Reddish orange colour pigment in yellow/orange/red fruits and vegetables and green leafy vegetables which include a-,B-, and y-carotenes and cryptoxanthin.
• Collagen:- Intracellular cementing substances which is protein matrix of cartilage, connective tissue, and bone.
• Oedema:- Retention of fluid in extracellular spaces. Sodium, the electrolyte in the extracellular fluid, is also retained along with water resulting in swelling.