Micronutrient Quick-Reference: Vitamins and Minerals at a Glance

What Are Micronutrients and Why Do They Matter?

Unlike macronutrients such as carbs, protein, and fat, micronutrients - vitamins and minerals - are needed only in small amounts. That word "small," however, is misleading: deficiencies in these compounds can disrupt virtually every system in the body, from immune defense to bone strength to energy metabolism.

Vitamins are organic molecules; minerals are inorganic elements. Both categories are considered essential because the body either cannot produce them at all or cannot produce enough to meet its needs. That makes dietary intake - and occasionally supplementation under medical guidance - the primary supply route.

This reference guide is organized to help you quickly locate key vitamins and minerals, understand what each one does, identify food sources, and recognize when intake may be falling short. It is general health information, not personalized medical advice. If you suspect a deficiency, consult a qualified healthcare professional for testing and guidance.

Key Vitamins: Functions, Food Sources, and Deficiency Signs

Vitamins are divided into two groups based on how the body stores them.

Fat-Soluble Vitamins (A, D, E, K)

These dissolve in fat and can be stored in body tissues, which means both deficiency and excessive intake are concerns.

• Vitamin A - Supports vision (especially night vision), immune function, and cell growth. Found in liver, dairy, eggs, and as beta-carotene in orange and dark-green vegetables. Deficiency can impair night vision and immune response.
• Vitamin D - Critical for calcium absorption, bone health, and immune modulation. Synthesized in skin upon sun exposure; dietary sources include fatty fish, egg yolks, and fortified foods. Deficiency is widespread and linked to bone loss and fatigue.
• Vitamin E - Acts as an antioxidant, protecting cell membranes from oxidative damage. Found in nuts, seeds, and vegetable oils. Isolated deficiency is uncommon in healthy adults but can occur with fat-malabsorption conditions.
• Vitamin K - Essential for blood clotting and bone metabolism. Vitamin K1 is abundant in leafy greens; K2 is found in fermented foods and some animal products. Deficiency increases bleeding risk.

Water-Soluble Vitamins (C and B-complex)

These are not stored in large amounts, making regular dietary intake important.

• Vitamin C - Supports collagen synthesis, immune function, and iron absorption. Citrus, bell peppers, strawberries, and broccoli are rich sources. Deficiency leads to scurvy, characterized by fatigue and impaired wound healing.
• B vitamins (B1, B2, B3, B5, B6, B7, B9, B12) - Collectively support energy metabolism, red blood cell production, and nervous system function. Whole grains, legumes, meat, dairy, and leafy greens supply most of the group. Vitamin B12 is found almost exclusively in animal products, making it a key concern for those following plant-based diets. See our plant-based eating guide for strategies around this nutrient.

Essential Minerals: What They Do and Where to Find Them

Minerals are classified as major minerals (required in larger amounts) or trace minerals (required in tiny amounts but still essential).

Major Minerals

• Calcium - The most abundant mineral in the body; foundational for bone and tooth strength, muscle contraction, and nerve signaling. Dairy, fortified plant milks, tofu made with calcium sulfate, and leafy greens are good sources. Long-term deficiency contributes to osteoporosis.
• Magnesium - Involved in over 300 enzyme reactions, including energy production and protein synthesis. Found in nuts, seeds, legumes, and whole grains. Low intake is associated with muscle cramps, fatigue, and elevated blood pressure.
• Potassium - Regulates fluid balance and supports heart and muscle function. Bananas, potatoes, beans, and leafy greens are reliable sources. Deficiency (hypokalemia) can cause weakness and irregular heart rhythm.
• Sodium - Works with potassium to maintain fluid balance and nerve transmission. Most US diets supply more than adequate amounts; excessive intake is associated with elevated blood pressure in susceptible individuals.

Key Trace Minerals

• Iron - Essential for oxygen transport via hemoglobin. Red meat, poultry, lentils, and fortified cereals are common sources. Iron-deficiency anemia is one of the most common nutritional deficiencies worldwide, particularly in women of reproductive age.
• Zinc - Supports immune function, wound healing, and DNA synthesis. Found in meat, shellfish, legumes, and seeds. Deficiency can impair immune response and slow wound healing.
• Iodine - Required for thyroid hormone production, which regulates metabolism. Iodized salt, seafood, and dairy are primary sources. Deficiency causes goiter and thyroid dysfunction.
• Selenium - Acts as an antioxidant cofactor and supports thyroid function. Brazil nuts, seafood, and whole grains are good sources.

When reading packaged foods, the % Daily Value column on a nutrition label can help you gauge how a given food contributes to your micronutrient intake. Our guide on reading a nutrition label explains how to interpret those figures without getting overwhelmed.

Getting the full spectrum of micronutrients doesn't require expensive specialty foods. A diverse diet built around vegetables, fruits, whole grains, legumes, and modest amounts of animal products (or fortified alternatives) covers the majority of needs for most healthy adults. For practical strategies, see eating well on a budget.

This article is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. If you have concerns about your nutrient intake or health status, please consult a qualified healthcare provider.