There are 13 essential vitamins your body needs to function properly: vitamins A, C, D, E, K, and eight B vitamins (B1, B2, B3, B5, B6, B7, B9, and B12). “Essential” means your body either can’t make them at all or can’t make enough, so you need to get them from food or supplements. These 13 vitamins split into two groups based on how your body absorbs and stores them.
Fat-Soluble vs. Water-Soluble Vitamins
Four vitamins, A, D, E, and K, are fat-soluble. Your body stores them in the liver, fatty tissue, and muscles, which means you don’t necessarily need to consume them every single day. It also means they can build up to harmful levels if you take too much over time. Absorbing these four vitamins requires dietary fat. When fat intake drops below about 5 grams per day, absorption of vitamin A and related compounds drops significantly. Normal bile and pancreatic function also play a role in absorbing vitamins E and K.
The remaining nine vitamins are water-soluble: vitamin C and all eight B vitamins. Because they dissolve in water, your body doesn’t store most of them. Excess amounts pass through your urine, so you need a steady supply from your diet. The one exception is B12, which your liver can store for years.
The Four Fat-Soluble Vitamins
Vitamin A
Vitamin A supports vision, immune function, and healthy skin. It helps produce a protein in the retina that allows you to see in dim light, and it stimulates key immune cells that fight infection. Good sources include eggs, milk, carrots, mangoes, and sweet potatoes. Deficiency starts with dry eyes and night blindness and can progress to permanent vision loss. The recommended daily amount is 700 to 900 mcg for adults, depending on sex.
Vitamin D
Vitamin D raises calcium and phosphate levels in your blood so your bones can mineralize properly. It also plays a role in nerve signaling and hormone function. Your skin produces vitamin D from sunlight, but dietary sources include fatty fish, fish liver oils, and fortified milk and cereals. Adults need 600 IU daily. Without enough, adults develop soft, weak bones (osteomalacia), and children develop rickets.
Vitamin E
Vitamin E is your body’s primary fat-soluble antioxidant. It protects the fatty membranes surrounding every cell from oxidative damage, keeping them stable and fluid. You’ll find it in nuts (especially almonds and peanuts), vegetable oils, broccoli, and spinach. The RDA is 15 mg for all adults. Severe deficiency, though rare, causes coordination problems, muscle weakness, and vision loss over time.
Vitamin K
Vitamin K is essential for blood clotting. Without it, your blood doesn’t coagulate normally, which shows up as easy bruising and prolonged bleeding. Newborns are particularly vulnerable because they’re born with very little vitamin K. The best food sources are dark leafy greens like spinach and kale, along with blueberries, figs, cheese, and eggs. Vitamin K is relatively heat-stable, so cooking doesn’t destroy much of it.
The Eight B Vitamins
The B vitamins work together to help your body convert food into energy and build essential molecules. Despite their shared name, each one has a distinct job.
B1 (thiamine) helps break down glucose. It acts as a helper molecule for several enzymes involved in energy production. Pork, fish, whole grains, and fortified cereals are the richest sources. Adults need 1.1 to 1.2 mg daily.
B2 (riboflavin) supports chemical reactions that transfer energy within cells. You’ll find it in eggs, organ meats, lean meat, asparagus, and broccoli. The RDA is 1.3 mg for adults.
B3 (niacin) is involved in hundreds of energy-transfer reactions throughout the body. Your body can also make small amounts from the amino acid tryptophan. Poultry, beef, fish, nuts, and legumes are good sources. Adults need 14 to 16 mg daily.
B5 (pantothenic acid) is a building block of coenzyme A, a molecule central to energy production and the formation of hormones. It’s found widely in foods, which is how it got its name (from the Greek word for “everywhere”).
B6 (pyridoxine) helps your body process amino acids, make neurotransmitters, and release stored energy from your muscles. Fish, beef liver, potatoes, and non-citrus fruits are the richest sources. Adults need 1.3 mg daily, rising to 1.5 to 1.7 mg after age 50. Deficiency can cause anemia, nerve damage, skin inflammation, and depression.
B7 (biotin) is needed to metabolize protein, fats, and carbohydrates. Deficiency is uncommon in healthy adults because gut bacteria produce some biotin and it’s present in many foods.
B9 (folate) is critical for making DNA and RNA, which makes it especially important during periods of rapid cell growth. Broccoli, Brussels sprouts, spinach, oranges, beans, and peas are all good sources. Adults need 400 mcg daily. During pregnancy, folate deficiency raises the risk of neural tube defects, preterm delivery, and low birth weight.
B12 (cobalamin) supports red blood cell production and nervous system health. It’s found almost exclusively in animal products: meat, fish, poultry, milk, and fortified cereals. The RDA is 2.4 mcg for adults. People following strict vegan diets are at higher risk of deficiency unless they supplement or eat fortified foods. Unlike other water-soluble vitamins, B12 can be stored in the liver for years.
Vitamin C
Vitamin C is water-soluble but stands apart from the B vitamins. It’s needed to build collagen (the structural protein in skin, tendons, and blood vessels), heal wounds, form bone, boost immune function, and help your body absorb iron from plant foods. It also works as a powerful antioxidant. Citrus fruits, tomatoes, potatoes, bell peppers, and strawberries are all rich sources. Women need 75 mg daily and men need 90 mg. Prolonged deficiency causes scurvy, with symptoms like bleeding gums, bruising, impaired wound healing, and joint pain appearing within the first three months.
Vitamin C is the most fragile vitamin in the kitchen. Boiling destroys a large share of it, with some vegetables retaining as little as 0% after boiling. Steaming and microwaving preserve far more because the food has less contact with water at lower temperatures. If you want to keep vitamin C intact, cook quickly, use minimal water, and consider eating some fruits and vegetables raw.
Upper Limits and Toxicity Risk
Because fat-soluble vitamins accumulate in your body, they carry higher toxicity risk. For adults ages 19 to 70, the tolerable upper intake levels are 3,000 mcg for vitamin A (from preformed sources, not plant-based carotenoids), 50 mcg (2,000 IU) for vitamin D, and 1,000 mg for vitamin E from supplements. Exceeding these levels consistently can cause real harm: too much vitamin A can damage the liver, and too much vitamin D can raise blood calcium to dangerous levels.
Among water-soluble vitamins, the upper limits are 2,000 mg for vitamin C, 35 mg for niacin, 100 mg for B6, and 1,000 mcg for folate from supplements or fortified foods. Going over the niacin limit commonly causes flushing and skin irritation; excess B6 over long periods can cause nerve damage. Several vitamins, including K, thiamine, riboflavin, B12, pantothenic acid, and biotin, don’t have established upper limits because there isn’t enough evidence of harm at high doses. That said, the absence of a formal limit doesn’t mean unlimited amounts are safe.
Getting All 13 From Food
Most people who eat a varied diet that includes vegetables, fruits, whole grains, lean protein, and some dairy or fortified alternatives will get adequate amounts of all 13 vitamins without supplements. A few groups face higher risk of specific gaps: people who eat no animal products may fall short on B12, those with limited sun exposure often need more vitamin D, and pregnant women have increased folate needs.
Cooking methods matter more than most people realize. While vitamin K and most B vitamins hold up reasonably well to heat, vitamin C and beta-carotene (a precursor your body converts to vitamin A) can drop substantially during boiling. Microwaving and steaming generally preserve more nutrients across the board. Eating a mix of raw and lightly cooked produce is a practical way to cover your bases.