What Is a Vitamin? The 13 Essential Vitamins and What Counts as One
What counts as a vitamin, the 13 essential vitamins with a plain role summary and UK adult amounts, and why choline, carnitine and minerals are not on the list.
Content last updated . This page has not been medically reviewed.
What "counts" as a vitamin
The sources read here define the group by what vitamins do and by the list of 13, not by a single chemical feature. A few documented points help explain why the list looks the way it does:- Some cannot be made by humans. Vitamin C is called a "true vitamin" in one narrative review because humans cannot make it. [3]
- Some can be made in part. Vitamin D is made by the body after skin is exposed to sun. [2] Bacteria in the large intestine make vitamin K. [4] Bowel bacteria also make B6 and biotin, though the NHS says it is not clear whether extra biotin is needed from the diet. [5]
- "Vitamin-like" nutrients exist. MedlinePlus names choline and carnitine as vitamin-like nutrients that the body needs. [2] Choline is not a B vitamin: see Choline.
- Minerals are a separate group. The NHS covers vitamins and minerals together but lists calcium, iodine, iron and others separately from the vitamins. [1] See Vitamins vs Minerals.
Proper evidence not found for one agreed rule beyond these lists: the MedlinePlus and NHS vitamin overviews and the NIDDK digestion page read for this page do not state one.
The 13 essential vitamins at a glance
Amounts are the UK figures the NHS gives for adults 19 to 64 (pages last reviewed August 2020). Other countries set different figures; see Vitamin Intake References Compared.| Vitamin | What it does | UK adults, NHS 2020 | Profile |
|---|---|---|---|
| Vitamin A (retinol) | Helps your immune system and your eyesight in dim light, and keeps your skin and the linings of your body healthy [6] | 700 µg men, 600 µg women a day [6] | More about Vitamin A (retinol) → |
| Vitamin D | Helps your body use calcium and phosphate, which keeps bones, teeth and muscles healthy [7] | 10 micrograms a day for ages 1 and over [7] | More about Vitamin D → |
| Vitamin E | Looks after your skin, eyes and immune defense, and works as an antioxidant [8][9] | 4 mg men, 3 mg women a day [8] | More about Vitamin E → |
| Vitamin K | Helps your blood clot and wounds heal [10] | About 1 microgram per kilogram of body weight a day [10] | More about Vitamin K → |
| Vitamin C | Protects your cells and supports skin, blood vessels, bones, cartilage and wound healing [11] | 40 mg a day [11] | More about Vitamin C → |
| Thiamin (B1) | Helps release energy from food and supports your nervous system [5] | 1 mg men, 0.8 mg women a day [5] | More about Thiamin (B1) → |
| Riboflavin (B2) | Supports skin, eyes and nerves, and helps release energy from food [5] | 1.3 mg men, 1.1 mg women a day [5] | More about Riboflavin (B2) → |
| Niacin (B3) | Helps release energy from food and supports your nerves and skin [5] | 16.5 mg men, 13.2 mg women a day [5] | More about Niacin (B3) → |
| Pantothenic acid (B5) | Helps release energy from the food you eat [5] | No amount set in the UK [5] | More about Pantothenic acid (B5) → |
| Vitamin B6 | Helps your body use and store energy from protein and carbohydrates, and make hemoglobin [5] | 1.4 mg men, 1.2 mg women a day [5] | More about Vitamin B6 → |
| Biotin (B7) | Helps your body make fatty acids [5] | No amount stated on the NHS page [5] | More about Biotin (B7) → |
| Folate (B9) | Supports healthy red blood cells; folic acid before pregnancy lowers the risk of neural tube defects [5] | 200 micrograms of folate a day [5] | More about Folate (B9) → |
| Vitamin B12 | Supports red blood cells and the nervous system, and works together with folate [5] | About 1.5 micrograms a day [5] | More about Vitamin B12 → |
Notes on the table: the NHS vitamin D figure of 10 micrograms equals 400 IU on the NHS conversion (1 microgram = 40 IU), and the NHS says that includes pregnant and breastfeeding women. [7] The NHS gives the folate figure for adults and separately recommends 400 micrograms of folic acid for people who are pregnant or could become pregnant, until 12 weeks of pregnancy; this is official UK advice, not personal advice. [5] The US uses different Recommended Dietary Allowances; MedlinePlus defines an RDA as the level enough to meet the needs of nearly all (97% to 98%) healthy people. [2]
Fat-soluble or water-soluble
Vitamins A, D, E and K are fat-soluble; vitamin C and all the B vitamins are water-soluble. [2] That affects storage and excess. Read Fat-Soluble vs Water-Soluble Vitamins.Frequently asked questions
How many essential vitamins are there?
MedlinePlus lists 13: vitamins A, C, D, E, K and eight B vitamins (thiamin, riboflavin, niacin, B6, B12, pantothenic acid, biotin and folate). [2]
Is choline a vitamin?
MedlinePlus names choline as a vitamin-like nutrient, not as one of the 13 essential vitamins. [2]
Can the body make any vitamins?
Partly. The body makes vitamin D after skin is exposed to sun, [2] and bowel bacteria produce some vitamin K, B6 and biotin. [4][5] Food is still the main source for most vitamins.
Are minerals vitamins?
No. The NHS covers vitamins and minerals in one guide and lists minerals such as calcium, iodine and iron alongside, not among, the vitamins. [1]
Do all countries use the same amounts?
No. For example, the NHS gives 40 mg of vitamin C a day for UK adults 19 to 64, [11] while MedlinePlus lists US RDAs of 90 mg for men and 75 mg for women aged 19 and older. [12]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety and who should ask first
References
- NHS (UK). Vitamins and minerals: Overview. Page last reviewed 3 August 2020. Read 2026-10-22.
- MedlinePlus, U.S. National Library of Medicine. Vitamins (encyclopedia article, reviewed 1/21/2025). Read 2026-10-22.
- Van der Velden U. Vitamin C and Its Role in Periodontal Diseases: The Past and the Present, a Narrative Review. Oral Health Prev Dent. 2020. Read 2026-10-22.
- NIDDK, U.S. National Institutes of Health. Your Digestive System & How it Works. Last reviewed December 2017. Read 2026-10-22.
- NHS (UK). Vitamins and minerals: B vitamins and folic acid. Page last reviewed 3 August 2020. Read 2026-10-22.
- NHS (UK). Vitamins and minerals: Vitamin A. Page last reviewed 3 August 2020. Read 2026-10-22.
- NHS (UK). Vitamins and minerals: Vitamin D. Page last reviewed 3 August 2020. Read 2026-10-22.
- NHS (UK). Vitamins and minerals: Vitamin E. Page last reviewed 3 August 2020. Read 2026-10-22.
- MedlinePlus, U.S. National Library of Medicine. Vitamin E (encyclopedia article, reviewed 1/21/2025). Read 2026-10-22.
- NHS (UK). Vitamins and minerals: Vitamin K. Page last reviewed 3 August 2020. Read 2026-10-22.
- NHS (UK). Vitamins and minerals: Vitamin C. Page last reviewed 3 August 2020. Read 2026-10-22.
- MedlinePlus, U.S. National Library of Medicine. Vitamin C (encyclopedia article, reviewed 1/21/2025). Read 2026-10-22.