Mitochondria is the prime reason why we are multicellular organisms. This organelle helps us live with adequate energy and even enables us to divert energy to thrive. Mitochondria not only gives us enough energy but also helps us make many important amino acids for our proteins. When the mitochondria becomes less healthy, due to a variety of reasons, we feel a loss of energy and is one of the major causes of chronic diseases. When the mitochondria produces less energy, the nucleus of the cell senses that change and errors might stream in and mutations are one of the downstream effects.

It is of prime importance to any organism to keep the mitochondria healthy and functional. In cells, where energy usage is prime, there exists more than a hundred thousand mitochondria.

There are many biochemical reactions that occur inside the mitochondria. Most of these biochemical conversions require the help of one or more enzymes and many times these enzymes are helped by coenzymes which are mostly vitamins. Mitochondrial supplements are basically vitamin supplements that enable the reactions to proceed inside the mitochondria at the right rate. When there is a deficiency of one or more coenzymes or vitamins, energy production or amino acid production and or fat production will be negatively affected. By supplementing the right vitamins from the outside the doctor is trying to ensure that the mitochondrial function streams smoothly. 

 Another important role of mitochondria is in the production of cellular water or metabolic water. This water is very special in that it has almost no or very low deuterium content. Deuterium is an isotope of hydrogen that is twice as heavy as ordinary hydrogen. Hydrogen molecules need passage through very delicate areas within the mitochondria made for the size of a hydrogen ion. When protons twice as heavy and twice as large, pass through these delicate channels, resulting in mitochondria being less effective or completely damaged. This influences the production of metabolic water and also mitochondrial energy. 

 Mitochondria also has a role in nitric oxide production that balances the size of our circulatory vessels. Another important aspect of mitochondria is a production of melatonin, which it consumes internally. The right amount of melatonin is important for many functions of the mitochondria including the production of nitric oxide. When nitric oxide is not produced properly the circulatory system might not respond well and it could impinge the circulation and indirectly affect the heart negatively.