13 Essential Vitamins: What They Do and Where to Get Them
What the 13 essential vitamins are, how fat-soluble and water-soluble vitamins differ, what each vitamin does, key food sources, and when supplements may be useful.
Key takeaways
- There are 13 essential vitamins. The body needs vitamins A, C, D, E, K and eight different B vitamins.[1]
- Vitamins fall into two main groups. Vitamins A, D, E and K are fat-soluble, while the B vitamins and vitamin C are water-soluble.[3]
- Each vitamin has different roles. Vitamins contribute to processes ranging from vision and blood formation to energy metabolism and bone health.[4]
- Food is an important source. A varied diet can provide many of the vitamins the body needs.[7]
- More is not always better. High-dose supplements do not automatically provide additional benefits and can sometimes cause harm.[8]
In this article
Vitamins are micronutrients that the body needs in relatively small amounts, but they take part in many important physiological processes. Some support vision and bone health, while others are involved in blood-cell formation, nervous-system function, collagen production or energy metabolism.[2]
There are 13 vitamins considered essential. They are divided into two main groups: fat-soluble vitamins, which are absorbed along with dietary fats, and water-soluble vitamins, which dissolve in water.
That does not mean that we need 13 different supplements. For most vitamins, food remains an important source, while supplements are more useful when there is a specific nutritional or medical reason for taking them.
What Are Vitamins?
Vitamins are organic substances required for normal body function. Unlike carbohydrates, fats and proteins, they are not a direct source of energy, but they participate in processes that help the body use nutrients and maintain normal physiological functions.[1]
Each vitamin has its own roles. Vitamin A is important for vision, vitamin C is required for collagen production, vitamin D contributes to calcium absorption, and several B vitamins participate in nutrient and energy metabolism.[4]
What Are the 13 Essential Vitamins?
The 13 essential vitamins are A, C, D, E, K and eight B vitamins: B1, B2, B3, B5, B6, B7, B9 and B12. These vitamins differ in their functions, food sources, metabolism and how the body stores or eliminates them.[6]
A simple way to understand them is to divide them into two families:
| Type | Vitamins |
|---|---|
| Fat-soluble | A, D, E, K |
| Water-soluble | B1, B2, B3, B5, B6, B7, B9, B12 and C |
This classification is more than a naming system. Solubility influences how vitamins are absorbed, transported, stored and eliminated from the body.[3]
Fat-Soluble Vitamins
The four fat-soluble vitamins are A, D, E and K. Their absorption is linked to normal fat digestion, and the body can retain them to different degrees, as explained in our comparison of fat-soluble vs. water-soluble vitamins.
This is also one reason high-dose supplementation should not automatically be viewed as better. Some fat-soluble vitamins can accumulate in the body and cause adverse effects when excessive amounts are taken.[5]
| Vitamin | Why It Matters | Food Sources |
|---|---|---|
| Vitamin A | Vision, immune function, growth, cell differentiation | Liver, eggs, dairy, carrots, sweet potatoes |
| Vitamin D | Calcium absorption, bone health, muscle function | Fatty fish, egg yolk, fortified foods |
| Vitamin E | Antioxidant function | Nuts, seeds, vegetable oils |
| Vitamin K | Normal blood clotting and vitamin K-dependent proteins | Leafy green vegetables, vegetable oils |
Vitamin A
Vitamin A is important for vision, immune function, reproduction and normal cell development. It can come from preformed vitamin A in certain animal foods or from provitamin A carotenoids such as beta-carotene in plant foods.[6]
Carrots, sweet potatoes and other orange vegetables are well known for their carotenoid content. Liver, eggs and some dairy products can provide preformed vitamin A.
Vitamin D
Vitamin D contributes to calcium absorption and supports bone health and normal muscle function. Its close relationship with calcium helps explain why adequate levels of both nutrients matter for maintaining healthy bones, a connection explored in our guide to vitamin D and calcium.
Unlike most vitamins, the body can produce vitamin D in the skin after exposure to UVB radiation. Food sources include fatty fish, egg yolk and fortified foods, while vitamin D status can also depend on sun exposure, season, age and other individual factors.[6]
Vitamin E
Vitamin E refers to several related compounds, but alpha-tocopherol is the form recognized as meeting human vitamin E requirements. It has antioxidant functions and helps protect cell membranes from oxidative damage.[6]
Nuts, seeds and vegetable oils are important food sources. Almonds and sunflower seeds are two practical examples that can be included in an everyday diet.
Vitamin K
Vitamin K is required for the activation of proteins involved in normal blood clotting and bone metabolism. Vitamin K1, or phylloquinone, is found mainly in leafy green vegetables, while vitamin K2 refers to several compounds known as menaquinones.[6]
People taking vitamin K antagonist anticoagulants such as warfarin should follow their clinician’s instructions regarding vitamin K intake. In many cases, keeping intake relatively consistent is more important than completely avoiding foods that contain vitamin K.[6]
Water-Soluble Vitamins
This group includes vitamin C and the eight B vitamins. They dissolve in water and are processed differently from fat-soluble vitamins, with some important differences in how individual nutrients are stored and eliminated.[3]
However, saying that the body simply excretes every excess amount of a water-soluble vitamin is too simplistic. Vitamin B12 can be stored in substantial amounts, and high doses of some B vitamins can still cause adverse effects.[5]
| Vitamin | Why It Matters | Food Sources |
|---|---|---|
| B1 – Thiamin | Energy metabolism, nerve function | Whole grains, pork, legumes, seeds |
| B2 – Riboflavin | Energy metabolism, cellular function | Dairy, eggs, meat, almonds |
| B3 – Niacin | Energy metabolism, cellular processes | Meat, fish, poultry, peanuts |
| B5 – Pantothenic Acid | Coenzyme A formation and metabolism | Meat, eggs, mushrooms, whole grains |
| B6 | Amino acid metabolism, neurotransmitters, hemoglobin | Fish, poultry, potatoes, chickpeas |
| B7 – Biotin | Metabolism of fats, carbohydrates and amino acids | Eggs, nuts, seeds |
| B9 – Folate | DNA synthesis and cell division | Leafy greens, legumes |
| B12 – Cobalamin | Nerve function, DNA, red blood cells | Meat, fish, eggs, dairy, fortified foods |
| C | Collagen production, antioxidant function, iron absorption | Peppers, citrus fruits, kiwi, broccoli |
B Vitamins
The eight B vitamins are often grouped under the term B-complex, but they are not one single substance. They participate in different physiological processes, many of which are connected with nutrient metabolism and cellular function.
Vitamin B9, or folate, is particularly important for DNA synthesis and cell division. Folic acid is the form used in supplements and fortified foods and is especially important before pregnancy and during the early weeks of pregnancy because of its role in reducing the risk of neural tube defects.[6]
Vitamin B12 is important for nervous-system function, red blood cell formation and DNA synthesis. It occurs naturally mainly in animal-derived foods, which is why people following a vegan diet need a reliable source of B12, such as fortified foods or appropriate supplementation.[6]
Certain digestive conditions, medications and changes associated with aging can also affect B12 status. These factors help explain why vitamin B12 deficiency is not always caused by insufficient dietary intake alone.
Vitamin C
Vitamin C is required for collagen production, contributes to antioxidant functions and improves the absorption of non-heme iron from plant foods. Humans cannot produce vitamin C, so it must be obtained from food or other dietary sources.[6]
Peppers, kiwi, citrus fruits, strawberries and broccoli are good sources. Vitamin C can be affected by prolonged storage and some cooking methods, and some of it may be lost into cooking water.[7]
Can You Get All Vitamins From Food?
A varied diet can provide many of the vitamins the body needs. Fruits, vegetables, legumes, whole grains, nuts, seeds, dairy or fortified alternatives and different protein sources all contribute to micronutrient intake. However, whether you can get all your vitamins from food depends on your dietary pattern and individual nutritional needs.[7]
Different foods provide different combinations of nutrients. For example, whole grains, legumes, eggs, dairy, meat and leafy vegetables are among the important food sources of B vitamins, although no single food group supplies all eight B vitamins in equal amounts.
Obtaining vitamins from food is only part of the picture. Age, gastrointestinal conditions, surgery and certain medications can affect vitamin absorption, making individual requirements different from general recommendations.
Some dietary patterns and life stages also require additional attention. Vegan diets need a reliable source of vitamin B12, vitamin D may require an individualized approach, and folic acid has specific recommendations before and during early pregnancy.[6]
Do You Need Vitamin Supplements?
The fact that the body needs 13 vitamins does not mean that everyone needs a supplement containing all 13. For a person with an adequate diet, taking additional amounts of every vitamin does not automatically provide additional health benefits.[8]
Supplements can be useful when there is a deficiency, a restrictive diet, increased nutritional requirements or a condition that affects absorption. Choosing a supplement based on an identified need is more useful than choosing one simply because it contains a long list of vitamins.[8]
Can You Take Too Many Vitamins?
Yes. The risk differs considerably from one vitamin to another, but supplements can contain amounts far higher than those normally obtained from food.[8]
Several vitamins have a Tolerable Upper Intake Level (UL). This is the highest average daily intake unlikely to cause adverse effects for most people — not a target amount that people should try to reach.[5]
It is also useful to look at the combination of products being used. A multivitamin, a B-complex supplement and another standalone supplement can contain some of the same vitamins, so the amounts may add up.[8]
Frequently asked questions
What Are the 13 Essential Vitamins?
The 13 essential vitamins are A, C, D, E, K, B1, B2, B3, B5, B6, B7, B9 and B12. Each has different physiological roles and dietary sources.[1]
They are divided into four fat-soluble vitamins and nine water-soluble vitamins. This classification helps explain some differences in absorption, storage and metabolism.
What Are the Fat-Soluble Vitamins?
The fat-soluble vitamins are A, D, E and K. Their absorption is connected to normal fat digestion, and the body can store them to different degrees.[3]
Because some can accumulate, very high supplemental doses deserve particular attention. Being fat-soluble does not mean that larger amounts are better.
What Are the Water-Soluble Vitamins?
The eight B vitamins and vitamin C are water-soluble. This does not mean that unlimited amounts are automatically safe.[3]
Vitamin B12 can be stored in the body, while long-term high doses of certain other B vitamins may cause adverse effects. Vitamin B6, for example, can affect the nerves when taken in excessive amounts over time.[6]
Why Are There No Vitamins B4, B8, B10 or B11?
In the past, several compounds were assigned numbers within the B-vitamin family. Later research showed that some of them did not meet the criteria required to be classified as essential vitamins.[3]
The numbering system was not reorganized after those discoveries. This is why the B-vitamin family now contains several apparent gaps.
Can You Get All 13 Vitamins From Food?
For many people, a varied diet can meet requirements for most vitamins. However, there are situations in which food alone may not provide enough or where specific recommendations apply.[7]
Vitamin B12 in vegan diets, vitamin D in certain circumstances, and folic acid before and during early pregnancy are important examples. Individual health conditions can also change nutritional requirements.
Do You Need All 13 Vitamins Every Day?
The body needs adequate amounts of all essential vitamins over time. That does not mean that you must precisely meet the recommended amount of every vitamin on every single day.[5]
Diet is more useful to think about as an overall pattern than as 13 separate boxes that have to be checked daily. Adequacy over time matters more than perfect day-to-day precision.
Final thoughts
The 13 essential vitamins become easier to understand when they are divided into two broad families: the fat-soluble vitamins A, D, E and K, and the water-soluble vitamins C and the eight B vitamins.
Each vitamin has its own functions and food sources. The goal is not to consume as many vitamins as possible, but to obtain adequate amounts for normal body function.
For most people, a varied diet remains the foundation. Supplements can play an important role, but they are most useful when they address a specific nutritional need rather than simply adding more vitamins.
References
- MedlinePlus — Vitamins. medlineplus.gov
- Harvard T.H. Chan School of Public Health — Vitamins and Minerals. nutritionsource.hsph.harvard.edu
- Merck Manual — Overview of Vitamins. merckmanuals.com
- Merck Manual — Sources, Functions and Effects of Vitamins. merckmanuals.com
- National Academies — Dietary Reference Intakes. nap.nationalacademies.org
- NIH Office of Dietary Supplements — Vitamin and Mineral Fact Sheets. ods.od.nih.gov
- Better Health Channel — Vitamins and Minerals. betterhealth.vic.gov.au
- Better Health Channel — Vitamin and Mineral Supplements. betterhealth.vic.gov.au
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