The two types of micronutrients are vitamins and minerals. These are nutrients your body needs in very small amounts, unlike macronutrients (protein, carbohydrates, and fat) which you need in grams per day. Despite the tiny quantities involved, micronutrients are essential for everything from building bones to converting food into energy, and deficiencies are remarkably common. A large global study covering 2003 to 2019 found that 56% of preschool-aged children and 69% of women of reproductive age were deficient in at least one micronutrient.
Vitamins: Water-Soluble and Fat-Soluble
There are 13 essential vitamins, split into two groups based on how your body absorbs and stores them.
Four vitamins are fat-soluble: A, D, E, and K. Your body absorbs them more easily when you eat them alongside dietary fat, and it stores extras in the liver, fatty tissue, and muscles. Because they accumulate over time, it’s possible (though uncommon from food alone) to build up too much.
The remaining nine are water-soluble: vitamin C and the eight B vitamins (B-1 through B-12). Your body doesn’t store most of them. Whatever it can’t use passes out through urine, which means you need a steady daily supply. The one exception is B-12, which the liver can hold onto for years.
Most vitamins work inside your cells as helpers for enzymes. B vitamins, for example, plug into enzymes that break down food for energy, transfer amino acids between molecules, and carry chemical groups that cells need to build DNA. Vitamin C plays a different role: it acts as an antioxidant and is required to produce collagen, the structural protein in tendons, ligaments, and bone. Among the fat-soluble vitamins, A is needed to form the pigments in your eyes that detect light, D helps your body absorb calcium and phosphorus, E protects cell membranes from damage, and K is essential for blood clotting.
Minerals: Major and Trace
Minerals are inorganic elements your body can’t manufacture. Like vitamins, they split into two subcategories.
Major minerals (also called macrominerals) are the ones you need in larger amounts: calcium, phosphorus, magnesium, sodium, potassium, chloride, and sulfur. Calcium and phosphorus make up most of your bone structure. Sodium and potassium regulate fluid balance and nerve signaling. Magnesium supports hundreds of enzyme reactions throughout the body.
Trace minerals are needed in much smaller quantities but are no less important. This group includes iron, zinc, copper, iodine, manganese, cobalt, fluoride, and selenium. Iron carries oxygen in your blood. Zinc supports immune function and wound healing. Iodine is required to make thyroid hormones. Some trace minerals, like zinc and copper, work directly inside enzymes as cofactors, essentially acting as the metal “key” that lets the enzyme do its job.
Where You Get Them
No single food covers all 13 vitamins and every essential mineral, but certain foods are especially dense in micronutrients.
For water-soluble vitamins, good sources include meat, poultry, and fish (B-3, B-6, B-12), eggs and whole grains (B-7), legumes and leafy greens like spinach (B-9), and citrus fruits, bell peppers, and strawberries (vitamin C). Because these vitamins aren’t stored long-term, eating a variety of these foods regularly matters more than loading up occasionally.
Fat-soluble vitamins come from a different set of foods. Vitamin A is found in liver, eggs, sweet potatoes, carrots, and spinach. Vitamin D is in fatty fish and fortified milk, though your skin also produces it from sunlight. Nuts, seeds, and vegetable oils supply vitamin E, while dark leafy greens like kale, broccoli, and cabbage are rich in vitamin K.
For major minerals, dairy products are the most reliable source of calcium. Potassium is widespread in fruits, vegetables, meat, and legumes. Magnesium concentrates in spinach, seeds, legumes, and whole grains. Trace minerals tend to come from protein-rich foods: red meat and legumes for iron, seafood and nuts for zinc, iodized salt for iodine.
How Much You Need
Recommended amounts for each micronutrient vary by age and sex. These guidelines, called Recommended Dietary Allowances, are set at levels sufficient to meet the needs of 97 to 98% of healthy people in a given group. A 30-year-old woman, for instance, needs more iron than a 30-year-old man, and a teenager needs more calcium than a middle-aged adult.
The NIH Office of Dietary Supplements publishes interactive tables where you can look up specific numbers for your demographic. In general, though, a diet that includes vegetables, fruits, whole grains, lean protein, and dairy (or fortified alternatives) covers most bases without supplementation.
What Deficiency Looks Like
Because micronutrients are involved in so many body processes, deficiencies tend to show up in broad, overlapping ways. Low iron causes fatigue, pale skin, and difficulty concentrating. Insufficient vitamin D leads to weakened bones and muscle pain. Too little vitamin C causes slow wound healing and, in severe cases, bleeding gums. Zinc deficiency impairs taste, slows healing, and weakens immune response.
Mild deficiencies are easy to miss because the symptoms are vague: tiredness, brain fog, frequent colds. They’re also surprisingly common even in wealthy countries, particularly for iron, vitamin D, and magnesium. People at higher risk include those with restricted diets (vegan, very low-calorie, or limited food access), pregnant women, older adults, and anyone with a condition that impairs nutrient absorption, such as celiac disease or inflammatory bowel disease.
A standard blood panel can check levels of several key micronutrients, and correcting a deficiency is usually straightforward through dietary changes or targeted supplementation.