Micronutrients: The Vitamins and Minerals Your Body Can't Make Itself

What Are Micronutrients?

Micronutrients are vitamins and minerals that the body requires in relatively small amounts but cannot synthesize in sufficient quantities on its own. Unlike macronutrients such as carbs, proteins, and fats, micronutrients don't supply calories. Instead, they serve as co-factors and structural components for nearly every physiological process — from energy metabolism and immune defense to bone formation and DNA repair.

The term essential in nutrition means the body cannot make enough of a nutrient on its own, so it must come from food. All vitamins are essential. Most minerals are as well, though the body can recycle some (like iron) more efficiently than others.

Vitamins: Fat-Soluble vs. Water-Soluble

Vitamins divide into two categories based on how the body absorbs and stores them:

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

These dissolve in dietary fat and are stored in fatty tissue and the liver. Because the body can accumulate reserves, deficiency develops slowly — but excessive intake from supplements can reach toxic levels over time.

• Vitamin A: Supports vision (especially in low light), immune function, and cell differentiation. Found in liver, dairy, eggs, and as provitamin A carotenoids in orange and dark-green produce.
• Vitamin D: Regulates calcium absorption and plays a role in immune signaling. Synthesized in skin exposed to UVB sunlight; dietary sources include fatty fish, egg yolks, and fortified foods.
• Vitamin E: Acts as a fat-soluble antioxidant protecting cell membranes. Concentrated in nuts, seeds, and vegetable oils.
• Vitamin K: Essential for blood clotting and bone metabolism. K1 comes primarily from leafy greens; K2 is found in fermented foods and some animal products.

Water-Soluble Vitamins (C and the B Vitamins)

These don't accumulate significantly in the body, so regular dietary intake matters more. Excesses are generally excreted in urine, though very high supplement doses of certain B vitamins can still cause harm.

• Vitamin C: Antioxidant, collagen synthesizer, and immune supporter. Citrus, bell peppers, kiwi, and broccoli are reliable sources.
• B vitamins (B1, B2, B3, B5, B6, B7, B9, B12): This group fuels energy metabolism, supports red blood cell production, and maintains nervous system function. B12 is found almost exclusively in animal products, making it a key consideration for people following plant-based diets. Folate (B9) is critical before and during pregnancy. See our nutrition glossary for plain-language definitions of related terms.

Key Minerals and Their Roles

Minerals are inorganic elements absorbed from soil and water through plant and animal foods. They fall broadly into macrominerals (needed in larger amounts, such as calcium, magnesium, and potassium) and trace minerals (needed in smaller quantities, such as iron, zinc, and selenium).

Bioavailability — how much of a mineral the body actually absorbs — varies with food source and preparation. For example, iron from animal foods (heme iron) is absorbed more readily than iron from plant foods (non-heme iron), though pairing non-heme sources with vitamin C can improve uptake.

Getting Enough: Practical Guidance

Dietary diversity is the most practical strategy for meeting micronutrient needs without relying heavily on supplements. Each food group contributes a distinct nutritional profile, which is why public health dietary guidelines consistently emphasize variety across fruits, vegetables, whole grains, proteins, and dairy or fortified alternatives.

Certain populations face higher risk of specific shortfalls:

• Vitamin D: People with limited sun exposure, darker skin tones, or older adults may need dietary or supplemental support — consult a healthcare provider for personalized guidance.
• Iron and B12: Those following vegetarian or vegan diets should pay particular attention to these, and B12 supplementation is widely recommended for vegans.
• Folate: People who are pregnant or planning to become pregnant are typically advised to supplement, in addition to consuming folate-rich foods.
• Calcium: Needs increase with age, particularly for postmenopausal women.

For a broader view of how micronutrients fit into overall nutrition, the Nutrition Basics hub covers foundational concepts including how macronutrients and micronutrients work together for everyday health.

This article is for general informational purposes only and does not constitute medical or dietary advice. For guidance tailored to your individual health needs, consult a registered dietitian or qualified healthcare professional.