To keep your nerve and red blood cells in good order, you need vitamin B12. It helps you create energy from what you eat and regulates cell division.

Calcium is essential in tooth and bone growth and maintenance, and performs a vital role in blood clotting and muscle contraction. An adult human has 206 bones, so you need plenty of calcium, especially when you’re growing.

Iodine is essential in maintaining a healthy metabolism (the rate at which the body burns energy) and rate of body growth. It’s the heaviest element commonly found in living organisms.

Protein is essential for muscle maintenance and growth. The body won’t function correctly without proteins. They are made from amino acids, some of which the body cannot produce itself and must be eaten. Or drunk.