Nutrient Food source Role in the body Vitamin A Iron Iodine Vitamin D Protein​

There are seven main classes of nutrients that the body needs. These are carbohydrates, proteins, fats, vitamins, minerals, fibre and water. It is important that everyone consumes these seven nutrients on a daily basis to help them build their bodies and maintain their health.

these are the 7 main classes of Nutrition that the body needs hope it will help you

i am going to guess that it is co2.