Issue 03 — Vitamins & Minerals

The Role of Micronutrients: Vitamins and Minerals Beyond the Basics

A structured overview of key vitamins and minerals, their documented functions in physiological processes, and the primary food sources through which they are obtained.

Colourful nutrient-rich foods including leafy greens, orange sweet potato, blueberries, walnuts, and avocado arranged on a dark background

What Are Micronutrients?

Micronutrients are dietary compounds required by the body in relatively small amounts but necessary for the regulation of a broad range of physiological processes. Unlike macronutrients — proteins, carbohydrates, and fats — micronutrients do not provide energy directly, yet they are indispensable for the metabolic pathways that make energy available and for the structural integrity of tissues.

Micronutrients are broadly categorised into vitamins and minerals. Vitamins are organic compounds, meaning they contain carbon, and are obtained from food because the human body cannot synthesise them in sufficient quantities. Minerals are inorganic elements derived from soil and water and absorbed by plants and animals.

Fat-Soluble Vitamins

Fat-soluble vitamins — A, D, E, and K — are absorbed alongside dietary fats and stored in the body's fatty tissues and liver. This storage capacity means deficiency may develop gradually, but also that excessive intake over time can accumulate in tissues.

Vitamin A Supports normal vision, immune function, and cell differentiation. Found in liver, dairy, eggs, and as provitamin A carotenoids in orange and dark green vegetables such as carrots, sweet potato, and spinach.

Vitamin D Regulates calcium absorption and phosphorus metabolism, contributing to bone mineralisation and immune function. Synthesised in skin upon exposure to ultraviolet light; dietary sources include oily fish, egg yolks, and fortified foods.

Vitamin E Functions primarily as a fat-soluble antioxidant, protecting cell membranes from oxidative processes. Rich sources include nuts, seeds, plant oils, and leafy green vegetables.

Vitamin K Essential for blood coagulation and bone protein synthesis. Found in green leafy vegetables (phylloquinone, K1) and fermented foods (menaquinones, K2).

Water-Soluble Vitamins

Water-soluble vitamins — vitamin C and the B-vitamin group — are not stored in the body to the same extent as fat-soluble vitamins. Excess amounts are generally excreted, which means regular dietary intake is important. The B vitamins are a functionally diverse group, many of which act as coenzymes in metabolic pathways.

Vitamin C (Ascorbic Acid) Involved in collagen synthesis, antioxidant activity, and the absorption of non-haem iron. Widely found in fruits and vegetables, particularly citrus fruit, berries, and peppers.

Thiamine (B1) Necessary for carbohydrate metabolism and nerve function. Present in whole grains, legumes, nuts, and pork.

Riboflavin (B2) Participates in energy metabolism and the metabolism of other B vitamins. Found in dairy, eggs, meat, and fortified cereals.

Niacin (B3) Involved in energy production via NAD and NADP coenzymes. Meat, fish, whole grains, and legumes are primary sources.

Folate (B9) Essential for DNA synthesis and cell division. Particularly important in periods of rapid cell growth. Found in dark leafy greens, legumes, and fortified foods.

Vitamin B12 (Cobalamin) Required for neurological function, red blood cell formation, and DNA synthesis. Found almost exclusively in animal-derived foods; fortified foods or supplementation are relevant considerations for those following plant-exclusive diets.

Fat-Soluble A, D, E, K

Water-Soluble C, B1, B2, B3, B5, B6, B7, B9, B12

Macro Minerals Ca, Mg, Na, K, P, S, Cl

Trace Minerals Fe, Zn, I, Se, Cu, Mn, Cr

Best Food Variety Whole, minimally processed foods

B12 Note Plant-exclusive diets require careful consideration of B12 sources

Key Minerals

Minerals are divided into macrominerals — required in larger amounts — and trace minerals, required in smaller quantities but no less essential.

Calcium The most abundant mineral in the body, concentrated in bones and teeth. Participates in muscle contraction and nerve signalling. Sources include dairy, fortified plant milks, tofu, and some leafy greens.

Iron A component of haemoglobin, transporting oxygen in the blood. Haem iron (from animal sources) is more bioavailable than non-haem iron (from plant sources). Vitamin C consumed alongside iron-rich plant foods enhances absorption.

Magnesium Involved in over 300 enzymatic reactions including energy production, protein synthesis, and nerve function. Found in nuts, seeds, whole grains, and dark leafy vegetables.

Zinc Participates in immune function, protein synthesis, and wound healing. Present in meat, shellfish, legumes, nuts, and seeds. Phytates in plant foods may reduce zinc bioavailability.

Iodine Essential for the synthesis of thyroid hormones, which regulate metabolism. Found in seafood, dairy, and iodised salt. Plant-exclusive diets may need to consider iodine sources carefully.

Selenium An antioxidant mineral that contributes to thyroid hormone metabolism and DNA synthesis. Brazil nuts are among the richest dietary sources; content in other foods varies with soil selenium levels.

Educational Context

This overview of vitamins and minerals is intended to describe the general roles and dietary sources of these nutrients. It does not constitute health advice, nor does it address individual nutritional needs or circumstances. The absence of a micronutrient in this summary does not imply it is unimportant. A varied, whole food dietary pattern is broadly described in nutritional science as supportive of adequate micronutrient intake.

Not a medical product. Always consult a healthcare professional before making any dietary changes.