Nutrition is the study of nutrients in food, how the body uses nutrients, and the relationship between diet, health, and disease. As molecular biology, biochemistry, and genetics advance, nutrition has become more focused on metabolism and metabolic pathways. Nutrition educates on how diseases, conditions, and problems can be prevented or reduced with a healthy diet. Nutrition also focuses on certain diseases and conditions may be caused by dietary factors, such as poor diet ( malnutrition), food allergies, and food intolerance.
Nutrition deals with the nutrients required by the body for a healthy functioning. There are macronutrients and micronutrients e.g. protein, carbohydrates, fats, vitamins, minerals, fiber, and water.

Nutrients are classified as Macronutrients and Micronutrients.

Macronutrients are needed in relatively large quantities by the body.
(There are certain macronutrients which don’t provide energy e.g. water and fiber.)
Micronutrients are needed in relatively small quantities by the body.

Energy macronutrients

Macronutrients like glucose, fructose, galactose, starch, proteins and fats provide energy to the body.
Energy macronutrients provide energy, which is measured either in kilocalories (kcal) or Joules. 1 kilocalorie = 4185.8 joules.
Carbohydrates provide 4 kcal per gram
Proteins provide 4 kcal per gram
Fats provide 9 kcal per gram
The other macronutrients are WATER and FIBER. Though they don’t provide energy, directly, to the body but are essential for almost all metabolic processes going on in the body.


These are the nutrients which are required in relatively small quantities as compared to macronutrients but are equally essential for a healthy body. These include minerals and vitamins.
Dietary minerals are the other chemical elements our bodies need, other than carbon, hydrogen, oxygen, and nitrogen.
A well balanced diet provides all the minerals required by the body to function appropriately. Minerals are sometimes added to certain foods to make up for any shortages. The best example is Iodine which is added to common salt in order to prevent Iodine deficiency which can result in thyroid probles and mental retardation.
Key minerals – essential for human biochemical processes:
Deficiency can profoundly affect the nervous system and heart.
Important for muscle, heart, and digestive health. Builds bone, assists in the synthesis and function of blood cells.
Essential for the structure of DNA, transporter of energy (ATP), component of cellular membrane, helps strengthen bones.
Processes ATP; required for good bones and management of proper muscle movement. Hundreds of enzymes rely on magnesium to work properly.
Required by many enzymes. Important for reproductive organ growth. Also important in gene expression and regulating the nervous and immune systems.
Essential component of hemoglobin, the oxygen-carrying compound in blood.
Manganese and Copper
Hundreds of body enzyme rely on Manganese and copper to function properly.
Required for the biosynthesis of thyroxine (one type of thyroid hormone).
Vital part of three important enzyme systems. It has a vital role in uric acid formation, in carbohydrate metabolism, and sulfite detoxification.


These are organic (Carbon containing) compounds we require in tiny amounts.

Most of the vitamins are not synthesized by our body, so, these are to be sourced from what we eat. There are water soluble vitamins i.e. eight B vitamins and vitamin C. Fat soluble are A, D, E, and K. Water-soluble vitamins need to be consumed more regularly because they are eliminated faster (in urine) and are not easily stored. Fat-soluble vitamins are more likely to accumulate in the body because they are harder to get rid of quickly. Vitamins play different and vital roles in body. Below is the list of essential vitamins and some of their roles.
Fat soluble vitamins
Vitamin A
Its deficiency can cause night blindness
Vitamin D
Deficiency can cause rickets, osteomalacia and autoimmune disorders.
Vitamin E
Can cause hemolytic anemia in newborn babies.
Vitamin K
Very important in blood coagulation in case of injury.
Water soluble vitamins
Vitamin B1- Thiamine
Deficiency can cause beriberi.
Vitamin B2 – Riboflavin
Deficiency results in mouth lesions and seborrhea.
Vitamin B3 – Niacin
Deficiency causes pellagra.
Vitamin B5 – Pantothenic acid
Deficiency results in tingling, pricking, or numbness of the skin.
Vitamin B6 – Pyridoxine
Anemia and peripheral neuropathy results due to its deficiency.
Vitamin B7 – Biotin
Deficiency promotes dermatitis and enteritis.
Vitamin B9 -Folic acid.
Neural tube defects in newborn are due to its deficiency.
Vitamin B12 – Methylcobalamin
Megaloblastic anemia is the result of deficiency.
Vitamin C – Ascorbic acid
Most common disease is scurvy because of its deficiency.