| Total essential vitamins | 13 (4 fat-soluble, 9 water-soluble) (National Institutes of Health, Office of Dietary Supplements) |
| Major minerals recognized | 7 (calcium, phosphorus, magnesium, sodium, potassium, chloride, sulfur) (Institute of Medicine, Dietary Reference Intakes) |
| Most common US deficiency | Vitamin D, followed by iron and magnesium (NHANES national nutrition survey data) |
| Groups at highest deficiency risk | Older adults, pregnant people, vegans/vegetarians, and those with limited sun exposure (NIH Office of Dietary Supplements) |
| Best general dietary pattern | Varied whole-foods diet including vegetables, fruits, legumes, whole grains, and lean protein (Dietary Guidelines for Americans) |
Why Micronutrients Matter
Macronutrients — proteins, carbohydrates, and fats — get most of the nutrition spotlight, but micronutrients do the foundational work that keeps every body system running. See our introduction to macronutrients if you want to understand the big picture first.
Vitamins and minerals are required in comparatively small amounts, yet they regulate metabolism, support immune function, enable nerve signaling, and build tissue. Deficiencies in even one can have cascading effects — and most shortfalls develop quietly over months before producing obvious symptoms.
This reference guide cuts through the noise by presenting the most clinically recognized vitamins and minerals in plain language: what each does, where to find it in food, and what populations are most at risk for falling short. It is designed as a lookup tool, not a supplement prescription. Always consult a qualified healthcare professional before changing your diet to address a suspected deficiency.
| Total essential vitamins | 13 (4 fat-soluble, 9 water-soluble) (National Institutes of Health, Office of Dietary Supplements) |
| Major minerals recognized | 7 (calcium, phosphorus, magnesium, sodium, potassium, chloride, sulfur) (Institute of Medicine, Dietary Reference Intakes) |
| Most common US deficiency | Vitamin D, followed by iron and magnesium (NHANES national nutrition survey data) |
| Groups at highest deficiency risk | Older adults, pregnant people, vegans/vegetarians, and those with limited sun exposure (NIH Office of Dietary Supplements) |
| Best general dietary pattern | Varied whole-foods diet including vegetables, fruits, legumes, whole grains, and lean protein (Dietary Guidelines for Americans) |
Essential Vitamins: Functions and Food Sources
Vitamins are organic compounds the body cannot synthesize in adequate quantities on its own. They fall into two broad categories: fat-soluble (A, D, E, K), which are stored in body fat and liver, and water-soluble (C and the eight B vitamins), which are not stored in meaningful amounts and must be replenished regularly through food.
Micronutrient
Vitamins and minerals required by the body in small amounts to support normal physiological function. Unlike macronutrients, they provide no calories but are essential for health.
Fat-soluble vitamin
Vitamins (A, D, E, K) that dissolve in fat, are absorbed through the gut with dietary fat, and can be stored in body tissue. Excess accumulation is possible, making very high supplemental doses a potential concern.
Water-soluble vitamin
Vitamins (C and the B-complex) that dissolve in water and are not stored in significant amounts, meaning regular dietary intake is necessary. Excess is generally excreted in urine.
Bioavailability
The proportion of a nutrient that is actually absorbed and used by the body after consumption. It varies by food form, preparation method, and what other foods are eaten alongside it.
Trace mineral
A mineral the body requires in very small amounts — typically less than 100 mg per day — such as iron, zinc, selenium, and iodine. They are no less critical than major minerals despite the smaller quantities needed.
Dietary Reference Intake (DRI)
A set of reference values established by health authorities to quantify the amounts of nutrients needed to meet the needs of healthy individuals. Includes Recommended Dietary Allowances (RDAs) and Tolerable Upper Intake Levels (ULs).
Fat-Soluble Vitamins
- Vitamin A: Supports vision in low light, skin integrity, and immune response. Found in liver, dairy, eggs, and as provitamin A carotenoids in orange and dark-green vegetables such as sweet potatoes and spinach.
- Vitamin D: Regulates calcium absorption and plays a role in immune and muscle function. Synthesized via sun exposure; dietary sources include fatty fish, egg yolks, and fortified dairy. Deficiency is widespread, especially in northern latitudes and among people with limited sun exposure.
- Vitamin E: Acts as an antioxidant protecting cell membranes from oxidative damage. Found in nuts, seeds, vegetable oils, and leafy greens.
- Vitamin K: Essential for blood clotting (K1) and bone metabolism (K2). Leafy greens such as kale and collards are rich in K1; fermented foods and some animal products provide K2.
Water-Soluble Vitamins
- Vitamin C: Antioxidant; required for collagen synthesis, iron absorption, and immune function. Found in citrus, bell peppers, strawberries, and broccoli.
- B1 (Thiamine): Energy metabolism; supports nerve function. Sources include whole grains, pork, and legumes.
- B2 (Riboflavin): Cellular energy production and antioxidant activation. Found in dairy, eggs, lean meats, and fortified cereals.
- B3 (Niacin): DNA repair, skin health, and energy conversion. Sources: poultry, fish, peanuts, and whole grains.
- B6 (Pyridoxine): Amino acid metabolism and neurotransmitter synthesis. Found in poultry, fish, potatoes, and bananas.
- B9 (Folate): Critical for DNA synthesis and cell division; especially important before and during pregnancy. Leafy greens, legumes, and fortified grains are primary sources.
- B12 (Cobalamin): Nerve function and red blood cell formation. Found almost exclusively in animal products; vegans and older adults are at elevated deficiency risk.
- Biotin: Fatty acid synthesis and glucose metabolism. Eggs, nuts, and salmon are good sources.
Key Minerals: What They Do and Where to Find Them
Minerals are inorganic elements that the body requires for structure (bones, teeth) and regulation (fluid balance, enzyme activity, electrical signaling). Major minerals are needed in larger amounts; trace minerals are required in smaller quantities but are no less essential.
~42%
US adults with vitamin D insufficiency
According to analysis of NHANES data published in Nutrition Research, vitamin D inadequacy is one of the most prevalent micronutrient gaps in American adults.
~10 million
Americans estimated to have iron deficiency
The Centers for Disease Control and Prevention estimates iron deficiency affects roughly 10 million people in the US, with young women and children most at risk.
48%
US adults not meeting magnesium requirements
Research using NHANES data suggests nearly half of American adults consume less magnesium than the Estimated Average Requirement from food alone.
Major Minerals
- Calcium: Bone and tooth structure, muscle contraction, nerve transmission. Dairy, fortified plant milks, leafy greens, and canned fish with soft bones.
- Magnesium: Involved in over 300 enzyme reactions, including energy production and blood pressure regulation. Found in nuts, seeds, legumes, whole grains, and dark leafy greens.
- Potassium: Fluid balance, nerve impulses, and muscle function including heart rhythm. Bananas, potatoes, avocados, beans, and dairy.
- Phosphorus: Bone structure and energy storage (ATP). Widespread in protein-rich foods: meat, fish, eggs, and legumes.
- Sodium: Fluid balance and nerve signaling. Present in most processed foods; most Americans exceed, rather than fall short of, recommended intake.
Essential Trace Minerals
- Iron: Oxygen transport via hemoglobin. Heme iron (red meat, poultry, fish) is more bioavailable; non-heme iron (legumes, fortified cereals, tofu) is enhanced by eating alongside vitamin C.
- Zinc: Immune function, wound healing, and protein synthesis. Oysters, red meat, poultry, beans, nuts, and whole grains.
- Iodine: Thyroid hormone production. Iodized salt, dairy, seafood, and seaweed.
- Selenium: Antioxidant defense and thyroid function. Brazil nuts, seafood, and whole grains.
- Copper: Iron metabolism and connective tissue formation. Organ meats, shellfish, nuts, and seeds.
For practical strategies to get more of these nutrients through everyday meals, see eating well on a tight schedule and habits worth auditing in your daily routine. Don't overlook dietary fiber — though not a vitamin or mineral, it works synergistically with many of these nutrients.
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 nutritional deficiencies or your diet, consult a registered dietitian or qualified healthcare provider.