Understanding Micronutrients
An overview of essential vitamins and minerals, their classifications, general functions within the body, and common food sources.
What Are Micronutrients?
Micronutrients are vitamins and minerals required in smaller quantities than macronutrients, yet they are critical for metabolic processes, immune function, and overall health.
Vitamins: Essential Organic Compounds
Vitamins are organic compounds produced by plants or animals. The body cannot synthesize most vitamins, so they must be obtained from food. Vitamins are classified based on their solubility.
Fat-Soluble Vitamins
Fat-soluble vitamins dissolve in dietary fat and are stored in body fat. They include:
| Vitamin | General Functions | Food Sources |
|---|---|---|
| Vitamin A | Vision, immune function, skin health | Sweet potatoes, carrots, spinach, kale, liver |
| Vitamin D | Calcium absorption, bone health, immune support | Fatty fish, egg yolks, mushrooms, fortified milk |
| Vitamin E | Antioxidant protection, cell health | Nuts, seeds, vegetable oils, leafy greens |
| Vitamin K | Blood clotting, bone mineralization | Leafy greens, broccoli, Brussels sprouts, cabbage |
Water-Soluble Vitamins
Water-soluble vitamins dissolve in water and are not stored in the body. They must be replenished regularly through diet.
| Vitamin Group | General Functions | Food Sources |
|---|---|---|
| Vitamin B Complex | Energy metabolism, nervous system function, DNA synthesis | Whole grains, legumes, meat, fish, eggs, dairy, leafy greens |
| B1 (Thiamine) | Carbohydrate metabolism, nerve function | Whole grains, pork, sunflower seeds, legumes |
| B6 (Pyridoxine) | Protein metabolism, neurotransmitter synthesis | Chickpeas, bananas, salmon, chicken, potatoes |
| B12 (Cobalamin) | Red blood cell formation, nervous system health | Fish, meat, poultry, eggs, dairy, fortified plant foods |
| Vitamin C | Immune function, collagen synthesis, antioxidant | Citrus fruits, berries, peppers, broccoli, tomatoes |
Minerals: Inorganic Elements
Minerals are inorganic elements that play essential roles in bone health, fluid balance, enzyme function, and energy production.
Macrominerals
Macrominerals are needed in larger quantities (though still considered "micro" compared to macronutrients).
| Mineral | General Functions | Food Sources |
|---|---|---|
| Calcium | Bone and teeth structure, muscle contraction, nerve function | Dairy, leafy greens, fortified plant milks, legumes |
| Magnesium | Muscle and nerve function, energy production, bone health | Leafy greens, nuts, seeds, whole grains, legumes |
| Phosphorus | Bone and teeth structure, energy metabolism | Meat, fish, dairy, nuts, seeds, whole grains |
| Potassium | Fluid balance, muscle contraction, heart function | Bananas, potatoes, spinach, legumes, avocados |
| Sodium | Fluid balance, nerve transmission, muscle contraction | Sea vegetables, naturally occurring in foods, salt |
Trace Minerals
Trace minerals are needed in very small amounts but are equally important for health.
| Mineral | General Functions | Food Sources |
|---|---|---|
| Iron | Oxygen transport, energy production, immune function | Red meat, poultry, fish, legumes, leafy greens, nuts |
| Zinc | Immune function, protein synthesis, wound healing | Meat, shellfish, legumes, nuts, seeds, whole grains |
| Copper | Energy production, collagen formation, antioxidant | Shellfish, nuts, seeds, whole grains, legumes |
| Selenium | Antioxidant protection, thyroid function, immune support | Brazil nuts, seafood, poultry, whole grains |
| Iodine | Thyroid hormone production, metabolism | Seafood, seaweed, dairy, eggs, iodized salt |
Phytonutrients and Plant Compounds
Beyond vitamins and minerals, plant foods contain thousands of bioactive compounds that support health.
Antioxidants
Compounds that neutralize free radicals, potentially reducing oxidative stress. Found in colorful fruits and vegetables, berries, nuts, and seeds.
Polyphenols
Plant compounds with potential health-supporting properties. Found in green tea, berries, red wine, olive oil, and dark chocolate.
Fiber
Indigestible carbohydrates that support digestive health and feed beneficial gut bacteria. Found in vegetables, fruits, whole grains, and legumes.
Flavonoids
A type of polyphenol with antioxidant properties. Found in citrus fruits, berries, red onions, and dark leafy greens.
Bioavailability and Food Synergy
The body's ability to absorb and utilize micronutrients depends on various factors.
Enhancement Factors
- Vitamin C enhances iron absorption from plant sources
- Healthy fats increase absorption of fat-soluble vitamins
- Whole foods provide nutrient combinations that work synergistically
- Cooking can increase bioavailability of some nutrients
Inhibition Factors
- Phytates in some seeds and grains can reduce mineral absorption
- Excessive heating may destroy some water-soluble vitamins
- Some compounds compete for absorption
- Individual digestive health affects nutrient uptake
Food-Based Approach to Micronutrients
Whole foods provide complex combinations of micronutrients along with fiber and phytonutrients. A diverse, colorful diet typically supports adequate micronutrient intake.
Dietary Diversity Strategies
- Eat a rainbow of fruits and vegetables
- Include whole grains regularly
- Consume legumes multiple times weekly
- Include nuts and seeds in meals
- Vary protein sources
Practical Considerations
- Seasonal produce maximizes nutrient density and affordability
- Local and fresh often provide higher nutrient content
- Frozen fruits and vegetables retain most nutrients
- Minimal processing preserves micronutrients
- Consistent intake is more important than perfection