- Major minerals are essential mineral elements required in amounts of **100mg or more per day** # Trace Minerals - Trace minerals are essential mineral elements required in amounts that are **less than 100mg per day** - They still perform vital roles - Obtaining adequate amounts of them from food is difficult - **Iron** is the most important trace mineral - Iron has 4 major roles: 1. **Oxygen transport** - Needed for production of hemoglobin (red blood cells), myoglobin (muscle cells), and cytochromes (most body cells) 2. Cell division - Required by an enzyme needed for DNA production 3. Immune system - Needed for production of lymphocytes (a type of white blood cell). Enables neutrophils (another type of white blood cell) to destroy bacteria 4. Nervous system - Needed to help maintain the myelin sheath that covers parts of certain nerve cells, needed for the production of neurotransmitters (eg, dopamine, epinephrine, and norepinephrine that regulate br)