'Vitamins and minerals are needed in this small quantities ' though they are an essential part of our balanced diet explain

Dear student,
Please find below the answer:

Vitamins and minerals are needed in small quantities ' though they are an essential part of our balanced diet. It is because vitamins and minerals are protective in function and play a role in protecting our body from diseases and infections. They have no role in growth of body or providing energy to the body like Proteins and carbohydrates. 

Hope this information clears your doubt.
Regards.