We know that eating a wide variety of foods is essential to ensure that the body gets all the Key Nutrients which are necessary in keeping us healthy and nourished. Everyone needs the same set of nutrients, but the quantities of these nutrients vary depending on age and other factors.

Make sure to get the right amounts of Key Nutrients that your body needs. In this section, get familiar with the Key Nutrients, their functions, and the different food sources of these nutrients. 

Protein
Functions: necessary to make enzymes, antibodies, body fluids, and hormones; important in building and maintaining body tissue.
Food sources: lean meat products, poultry, fish, eggs, milk, cheese, dried beans, nuts (soaked or roasted) 

Calcium
Functions: make bones and teeth healthy; helps in blood clotting
Food sources: milk, yogurt, cheese, leafy vegetables 

Iron
Functions:
needed to make haemoglobin - the substance which transports oxygen  to the muscles and other parts of the body
Food sources: lean red meat, fish, poultry, shellfish, oysters, whole grains, cereals. 

Zinc
Functions: necessary in forming enzymes and growth and repair of tissues; cell reproduction
Food sources: lean meat, seafood, eggs, whole grains, green and leafy vegetables 

Vitamin A
Functions: helps keep skin, hair, and membranes healthy; helps eyes adjust to dim light
Food sources: dark green and yellow vegetables (broccoli, squash, sweet potatoes), liver, yellow fruits, eggs, milk 
 
Vitamin C / Ascorbic Acid
Functions: boosts the body's resistance to infection; improves iron absorption; helps in holding cells together
Food sources: citrus fruits, green and red peppers, broccoli, cabbage, cauliflower

Vitamin D
Functions: helps make bones and teeth strong and healthy
Food sources: milk, cheese, eggs, liver 

Folic Acid / Folate
Functions: Necessary in developing red blood cells; helps reduce risk of having spinal birth defects
Food sources: legumes, liver, dark green and leafy vegetables.

These are just some of the Key Nutrients that play a big role in the overall growth and development of a person. To avoid any nutrient deficiencies, the best thing that you can do is to eat a wide range of nutrient-rich foods.
With balanced diet and enough exercise, you will feel and look better and healthier.