There are 7 major minerals and 10 trace minerals. There are 4 minerals required in ultratrace amounts that might be essential. Among the 7 major minerals, calcium and phosphorous are the most common. These are found in skeletal bone, teeth and muscle. Magnesium is found in much smaller amounts but is also important to bones.
Sulfur is present as a part of proteins and vitamins.
These are required in smaller amounts. Many of these minerals are parts of other compounds in the body. For example, iron is an important part of hemoglobin, which keeps oxygen in the blood. Iodine is a part of the thyroid hormones, and selenium is part of the important antioxidant, glutathione peroxidase. These are present in such small amounts it is hard to study if they are truly essential to life.