Micronutrients: Videos & Practice Problems

Water-soluble vitamins, such as B-complex and C, dissolve in water and are not stored in the body for long periods. Excess amounts are excreted through urine, so they need to be consumed regularly. In contrast, fat-soluble vitamins (A, D, E, and K) dissolve in fat and are stored in the body's fatty tissues and liver. Because they are stored, consuming them in excessive amounts can lead to toxicity. Both types of vitamins play essential roles in various physiological functions, but their solubility determines how they are absorbed, stored, and excreted by the body.

Vitamins and minerals are considered micronutrients because they are required by the body in much smaller amounts compared to macronutrients like carbohydrates, proteins, and fats. Despite their small required quantities, they are essential for numerous physiological processes, such as enzyme function, bone health, and cellular repair. Unlike macronutrients, they do not provide energy but are crucial for maintaining overall health and supporting bodily functions.

Vitamins are organic compounds containing carbon, while minerals are inorganic elements found on the periodic table. Vitamins are categorized into water-soluble (B and C) and fat-soluble (A, D, E, K) groups, whereas minerals are divided into major minerals (needed in amounts >100 mg/day) and trace minerals (<100 mg/day). Vitamins often act as coenzymes or antioxidants, while minerals play roles in structural functions (e.g., calcium in bones) and maintaining ion balance (e.g., sodium and potassium). Both are essential for health but differ in their chemical nature and roles in the body.

A varied diet is the best source of vitamins and minerals because it ensures a balanced intake of all essential nutrients. Different foods provide different vitamins and minerals, so consuming a wide range of fruits, vegetables, whole grains, proteins, and dairy helps meet the body's diverse nutritional needs. While supplements can help in specific cases, such as deficiencies, they may lead to imbalances or excessive intake if not carefully managed. A natural, varied diet also provides additional benefits like fiber and phytonutrients that supplements lack.

Excessive intake of fat-soluble vitamins (A, D, E, and K) can lead to toxicity because these vitamins are stored in the body's fat tissues and liver rather than excreted in urine. For example, too much vitamin A can cause hypervitaminosis A, leading to symptoms like nausea, dizziness, and even liver damage. Similarly, excessive vitamin D can result in hypercalcemia, causing kidney damage and calcium deposits in tissues. While toxicity is rare and usually requires very high doses, it underscores the importance of consuming these vitamins in appropriate amounts.

Trace minerals are minerals required by the body in amounts less than 100 mg per day. Examples include iron, fluoride, iodine, and molybdenum. Despite their small required quantities, they are vital for various physiological functions. For instance, iron is essential for oxygen transport in blood, iodine supports thyroid function, and fluoride strengthens teeth. A deficiency in trace minerals can lead to health issues, such as anemia (iron deficiency) or goiter (iodine deficiency), highlighting their importance in maintaining overall health.