IB Sports, exercise and health science A.2.2.3 Micronutrients and Their Roles in the Body Notes

Micronutrients enable energy transfer and tissue synthesis

1. Unlike macronutrients (such as proteins, fats, and carbohydrates), micronutrients do not provide energy (calories) but are crucial for numerous metabolic processes.
2. Micronutrients are required in small amounts. Despite being needed in smaller quantities, they are vital for good health.
3. These nutrients facilitate critical functions such as immune defense, cell function, and energy metabolism.

Micronutrients are divided into vitamins and minerals

Vitamins

1. Fat-soluble vitamins: These are stored in the body's fat and liver. Examples include vitamins A, D, E, and K.
2. Water-soluble vitamins: These are not stored in the body and are excreted in urine. Examples include vitamin C and the B-vitamins (B1, B2, B3, B6, B12, folate, etc.).

Minerals

1. Major minerals: Required in larger amounts, including calcium, phosphorus, magnesium, sodium, potassium, and chloride.
2. Trace minerals: Required in smaller amounts but still crucial for health, including iron, zinc, copper, iodine, and selenium.

Micronutrients enable energy transfer, tissue maintenance, and regulation

Facilitate Energy Transfer

1. Micronutrients, particularly B vitamins, are essential for converting food into usable energy.
2. They act as coenzymes in metabolic pathways such as glycolysis, the citric acid cycle, and oxidative phosphorylation.

Support Tissue Synthesis and Maintenance

1. Vitamins like Vitamin A and C, as well as minerals such as calcium, are involved in tissue growth and repair.
2. Different vitamins support tissue growth and repair (for example collagen synthesis and epithelial health), but specific vitamin functions are not assessed.

Maintain Bodily Functions

1. Micronutrients regulate various body functions, including immune response, bone health, blood clotting, and fluid balance.

Key Micronutrients and Their Roles

Iron

1. Body iron distribution: About 66% of the body's iron sits inside haemoglobin in red blood cells. Most of the rest is in myoglobin inside muscle fibres.
2. Iron is a crucial mineral involved in the transport of oxygen throughout the body. It is a key component of haemoglobin, a protein found in red blood cells, and myoglobin, a protein in muscle cells.
3. Iron binds to oxygen in the lungs, allowing haemoglobin to transport it to tissues, and myoglobin stores oxygen in muscles, releasing it during physical activity.