Journal of Nutrition Science Research
Open Access

While macronutrients provide the energy our bodies need, micronutrients-vitamins and minerals-are equally vital for maintaining health, supporting metabolism, and preventing disease. Required in smaller amounts, these nutrients act as cofactors, antioxidants, and structural components critical to numerous physiological functions. Deficiencies or imbalances in micronutrients can lead to serious health consequences, yet many populations worldwide still suffer from inadequate intake. Understanding the roles of key vitamins and minerals, their food sources, and how to ensure sufficient intake is essential for optimal nutrition and well-being [1-4].

Vitamins: The Organic Micronutrients

Vitamins are organic compounds classified into two groups: fat-soluble (A, D, E, and K) and water-soluble (B-complex and C). Each vitamin performs unique roles, often acting as coenzymes to enable enzymatic reactions that sustain metabolism, immune function, growth, and repair.

Fat-Soluble Vitamins: These vitamins dissolve in fats and are stored in the body’s fatty tissues and liver. Vitamin A is essential for vision, immune function, and cell growth. Vitamin D regulates calcium absorption, supporting bone health and immune regulation. Vitamin E acts as a powerful antioxidant protecting cells from oxidative damage. Vitamin K is crucial for blood clotting and bone metabolism. Because fat-soluble vitamins are stored, excessive intake can sometimes cause toxicity, so balance is important.

Water-Soluble Vitamins: These vitamins dissolve in water and are generally not stored in large amounts, requiring regular dietary intake. The B-complex vitamins-including B1 (thiamine), B2 (riboflavin), B3 (niacin), B6, B12, folate, and others—play critical roles in energy metabolism, red blood cell production, and nervous system health. Vitamin C supports collagen synthesis, immune defense, and acts as an antioxidant [5].

Deficiencies in vitamins can cause distinct diseases: vitamin A deficiency leads to vision problems and increased infection risk; vitamin D deficiency causes rickets or osteomalacia; B12 deficiency can result in anemia and neurological impairments; and vitamin C deficiency leads to scurvy.

Minerals: The Inorganic Micronutrients

Minerals are inorganic elements essential for structural, regulatory, and catalytic roles in the body. They are categorized as macro minerals (required in larger amounts) and trace minerals (needed in minute quantities).

Macro minerals: Calcium is vital for bone structure, muscle contraction, and nerve transmission. Magnesium supports hundreds of enzymatic reactions, including energy production and muscle function. Potassium and sodium regulate fluid balance, nerve impulses, and muscle contractions. Phosphorus is key for bone health and energy metabolism.

Trace Minerals: Iron is necessary for oxygen transport via haemoglobin and energy metabolism. Zinc supports immune function, wound healing, and DNA synthesis. Iodine is critical for thyroid hormone production, which regulates metabolism. Selenium acts as an antioxidant, protecting cells from damage. Other trace minerals include copper, manganese, chromium, and fluoride, each contributing to specific physiological processes [6, 7].

Mineral deficiencies vary by population and geography. Iron deficiency is the most common worldwide, leading to anaemia and impaired cognitive function. Iodine deficiency can cause goiter and developmental delays. Calcium and magnesium deficiencies weaken bones and muscles.

Food Sources and Bioavailability

Micronutrients come from diverse food sources. Fat-soluble vitamins are abundant in fatty fish, dairy, eggs, and leafy greens. Water-soluble vitamins are found in fruits, vegetables, whole grains, legumes, and animal products. Minerals are widely distributed in meats, dairy, nuts, seeds, vegetables, and fortified foods [8-10].

Bioavailability—the proportion of a nutrient absorbed and utilized-can vary based on food preparation, presence of enhancers or inhibitors, and individual health status. For example, vitamin C enhances iron absorption, while phytates in grains can inhibit mineral uptake. Cooking methods and food combinations can therefore influence micronutrient status.

Ensuring Adequate Micronutrient Intake

Achieving adequate micronutrient intake requires a varied and balanced diet rich in fruits, vegetables, whole grains, lean proteins, and healthy fats. Populations at risk—such as pregnant women, young children, the elderly, and those with limited diets—may require supplementation or fortified foods to meet their needs.

Public health strategies like food fortification (iodized salt, vitamin D–fortified milk) have been effective in reducing deficiencies on a large scale. However, excessive supplementation can lead to toxicity; thus, intake should be monitored carefully.

Conclusion

Micronutrients, though required in small amounts, are indispensable for life and health. Vitamins and minerals support countless biochemical reactions, structural functions, and immune defences. Inadequate intake can result in severe health consequences, highlighting the need for balanced diets and, when necessary, targeted interventions. Awareness of micronutrient roles, sources, and requirements empowers individuals and health professionals to promote nutritional adequacy and enhance quality of life.