How do these micronutrients help for normal growth? 
Poor nutrition in the child especially in the first 2 years of life can slow a child’s physical and mental development for the rest of his/her life. Of all the micronutrients, deficiency of vitamin A and iron are the commonest and it has been found that children with these deficiencies have vision difficulty (due to vitamin A deficiency) and impaired physical/mental development (due to iron deficiency). Also deficiency of vitamin D, zinc, iodine are also associated with poor growth. Most of the vitamins and minerals have an essential role in key chemical pathways in the body and specific vitamin deficiency can lead to specific symptoms.

What are daily micronutrients requirements? 
Individual requirement of each nutrient is related to age, gender, level of physical activity and state of health for e.g. in a preschooler (child between 1-3 years of age), though protein requirement does not increase much, there is an increased need for all vitamins, iron, calcium, phosphorus as well as other minerals as children are active and growing rapidly. Preschoolers and children are highly vulnerable to micronutrient deficiencies as they have low body stores of these nutrients, they may have low intake due to improper feeding practices and increased losses due to inter current infections.

Which are common food sources of vitamins and minerals?
All green leafy vegetables and fruits are good sources of these micronutrients. In overcooked vegetables, these vitamins and minerals are destroyed and thus one should avoid overcooking vegetables. Particular food items have higher content of a particular micronutrient for e.g. milk and dairy products, ragi are good sources of calcium, coconut water is a good source of potassium.

Certain food items are fortified with vitamins or minerals to improve consumption of these micronutrients for e.g. table salt is fortified with iodine (iodized salt) to prevent iodine deficiency growth.

What is the role of various vitamins on growth?
Role of vitamin A:- Deficiency of vitamin A can lead to night blindness and poor height gain especially in preschoolers above 1 year. These children are also prone to more complications with infections.

Role of vitamin D:- Deficiency of vitamin leads to poor height gain and bone deformities.

Role of vitamin B6 (pyridoxine):- Deficiency of vitamin B6 results in skin rash, anemia and mental confusions. In children less than 1 year of age, vitamin B6 deficiency adversely affects growth.

Role of other vitamin B complex:- Other vitamin B complex vitamins are usually deficient in undernourished children. Thiamine deficiency can result in a disease called as “Beri-Beri” that can affect heart and the nervous system. Nicotinic acid deficiency can result in skin rash and riboflavin deficiency can results in chapped, broken skin around lips and anemia. Vitamin C deficiency can lead to “scurvy” characterized by bone pain (limb pains), bleeding gums and poor wound healing. Vitamin B12 folic acid deficiency can lead to anemia and vitamin K deficiency can cause tendency for bleeding, vitamin E deficiency can cause neurological problems.

What is the role of various minerals on growth?
Role of Iron: Iron deficiency results in anemia. In young children, it leads to delay in acquisition of cognitive skills and development.

Role of Zinc: Zinc deficiency leads to slowing of growth, skin rashes, impaired immunity and diarrhea.

Role of Iodine: Iodine deficiency in children lead to poor formation of thyroid hormones. Low thyroid hormone level can result in cognitive impairment, growth impairment and neurological problems. Treatment after clinical symptoms arise may not reverse these changes and thus prevention of iodine deficiency is essential.

Role of Copper: Copper deficiency can cause anemia and fractures

Role of Calcium: Calcium deficiency can cause bone deformities and poor height gain

Role of Phosphorus: Phosphorus deficiency is rare as phosphorus is present in all food items. However phosphorus deficiency can lead to poor bone growth.

Role of Selenium: Selenium deficiency can cause heart problems

Role of Chromium: Chromium deficiency can cause neurological problems

Role of Fluoride: Fluoride deficiency can cause dental caries.

Conclusion:- Thus apart from adequate proteins, fats, carbohydrates in diet, it is essential that micronutrients are taken adequately to maintain proper growth and proper functioning of various tissues and organs.