Last reviewed on 11 September 2026.
NNWA publishes the name and qualifications of everyone who writes and checks its material. You can see the full teaching team on the faculty page.
Here is that list, with each vitamin's chemical name, its main job, a sign of running short, and Indian foods that supply it.
What are the 13 vitamins?
There are thirteen: vitamins A, D, E and K, which dissolve in fat, and vitamin C plus eight B vitamins, which dissolve in water. The B group is thiamin (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5), pyridoxine (B6), biotin (B7), folate (B9) and cobalamin (B12). Each is an organic compound the body needs in tiny amounts and cannot make in sufficient quantity, so it must come from food, from sunlight in the case of vitamin D, or, for a few people, from supplements.
Where does the word vitamin come from?
The Polish-born biochemist Casimir Funk coined "vitamine" in 1912, from "vital amine", because he believed these substances were all amines, a type of nitrogen compound. Funk was trying to isolate the substance in rice bran that prevents beriberi, later identified as thiamin. As more were discovered, it became clear that many are not amines at all, and in 1920 the British biochemist Jack Drummond suggested dropping the final "e". The shorter spelling has stood ever since.
Which vitamins are fat-soluble and which are water-soluble?
A, D, E and K are fat-soluble; C and the eight B vitamins are water-soluble. Fat-soluble vitamins are absorbed along with dietary fat, travel in the blood with fats and are stored in the liver and fatty tissue. Water-soluble vitamins dissolve in the watery parts of food and blood, are stored in small amounts, and any surplus is mostly passed in urine. Vitamin B12 is the notable exception, because the liver holds a store that can last a few years.
| Fat-soluble | Water-soluble | |
|---|---|---|
| Which ones | A, D, E and K | C and the eight B vitamins |
| How they are absorbed | Along with the fat in a meal | Dissolved in the watery part of food and blood |
| Storage | Held in the liver and fatty tissue | Kept in small amounts only |
| Surplus | Builds up, so high doses can do harm | Mostly passed out in urine |
B12 is the exception on the right-hand side, because the liver holds a store that can last a few years.
Why does solubility matter for toxicity?
Because stored vitamins can build up to harmful levels, while most water-soluble surpluses are simply excreted. Too much vitamin A over time can damage the liver and, in pregnancy, the unborn baby, and too much vitamin D raises blood calcium to dangerous levels. Nearly all such cases come from supplements, not food. Water-soluble does not always mean harmless, though: high-dose vitamin B6 taken for months can damage nerves, and very large doses of niacin can harm the liver. A sensible rule is that any dose far above the daily requirement needs a clear medical reason.
What is vitamin A called chemically, and what does it do?
Vitamin A is retinol in its preformed state, and it lets the eyes adapt to dim light and keeps the linings of the eyes, gut and airways healthy. Night blindness is the first sign of deficiency, and in children it can progress to eye damage and more severe infections. Retinol comes from liver, egg yolk, milk, ghee and fish; beta-carotene, which the body converts, comes from carrot, pumpkin, mango, papaya and dark greens such as drumstick leaves. India's child dosing programme is covered in the post on vitamin A deficiency and food sources.
What are vitamins D and E called chemically?
Vitamin D is calciferol (D3 is cholecalciferol, D2 ergocalciferol) and vitamin E is tocopherol. Vitamin D helps the gut absorb calcium and keeps bones mineralised; deficiency causes rickets in children and soft, aching bones in adults. Skin makes it in sunlight, and food sources are limited to oily fish, egg yolk and fortified milk or oil, which is why deficiency is so common, as the post on vitamin D deficiency in India explains. Vitamin E protects cell membranes from oxidation. Deficiency is rare and mostly seen with fat malabsorption, causing nerve and muscle problems. Almonds, sunflower seeds, groundnuts and vegetable oils are good sources.
What are the chemical names of vitamin K?
Vitamin K1 is phylloquinone and K2 is a family called menaquinones; both activate the proteins that make blood clot, along with some bone proteins. Deficiency causes easy bruising and bleeding; it is uncommon in healthy adults but a real danger for newborns, which is why babies are given an injection at birth. Phylloquinone comes from green leafy vegetables such as spinach, methi and mustard greens, and menaquinones from fermented foods, cheese and egg yolk. The newborn dose and the warfarin question are covered in the post on vitamin K functions and deficiency.
What is the chemical name of vitamin C?
Ascorbic acid. Vitamin C is needed to make collagen, the protein framework of skin, gums, blood vessels and scar tissue, and it helps the gut absorb iron from plant foods. Deficiency causes scurvy, with bleeding gums, bruising and slow healing. Amla and guava are among the richest foods anywhere, and capsicum, citrus fruit, papaya and green leafy vegetables are good too. It is easily destroyed by heat and long cooking, so some raw fruit or salad each day is the reliable way to cover it.
What do thiamin (B1) and riboflavin (B2) do?
Thiamin (B1) helps the body turn carbohydrate into energy and keeps nerves and heart muscle working. Deficiency causes beriberi, and in heavy drinkers a serious brain disorder called Wernicke's encephalopathy. Whole grains, pulses and groundnuts are good sources; polishing rice removes much of it, while parboiling drives some into the grain before milling. Riboflavin (B2) is part of the enzymes that release energy from food. A shortfall shows as cracks at the corners of the mouth and a sore, magenta-coloured tongue. Milk, curd, eggs and green leafy vegetables supply it.
Niacin and pantothenic acid: vitamins B3 and B5
Niacin (B3), which includes nicotinic acid and nicotinamide, is central to energy metabolism, and the body can also make some from the amino acid tryptophan. Deficiency causes pellagra, remembered by the three Ds: dermatitis, diarrhoea and dementia. It was historically common where maize or jowar made up most of the diet. Groundnuts, pulses, fish, chicken and whole grains are good sources. Pantothenic acid (B5) forms part of coenzyme A, used in releasing energy from fat and carbohydrate. Its name comes from the Greek for "from everywhere", and deficiency is almost unknown because nearly every food contains some.
Pyridoxine and biotin: vitamins B6 and B7
Pyridoxine (B6) takes part in more than a hundred enzyme reactions, mostly in protein metabolism, and helps make haemoglobin and brain chemicals. Deficiency can cause anaemia, a scaly rash, a sore mouth, confusion and low mood; chickpeas, bananas, potatoes, fish and chicken are good sources. Biotin (B7) helps enzymes that process fat, carbohydrate and protein. True deficiency is rare and shows as thinning hair and a red, scaly rash around the eyes, nose and mouth; egg yolk, groundnuts and soybeans supply it. High-dose biotin supplements can distort thyroid and heart blood tests, so tell the laboratory if you take them.
Folate and cobalamin: vitamins B9 and B12
Folate (B9), called folic acid in its synthetic form, is needed to make DNA and new cells. Deficiency causes megaloblastic anaemia, and low levels around conception raise the risk of neural tube defects in the baby, which is why folic acid is advised before and in early pregnancy. Green leafy vegetables, pulses such as rajma and chana, and liver are good sources. Cobalamin (B12) keeps nerves healthy and helps form red blood cells; deficiency causes anaemia, tingling, numbness and memory problems. It comes only from animal foods such as milk, curd, paneer, eggs, fish and meat, which leaves many Indian vegetarians short, as the post on vitamin B12 for vegetarians explains.
Why do the B vitamin numbers skip?
Because several substances were given B numbers during the early rush of discoveries and later dropped. B4, B8, B10 and B11 were each named at some point, then found not to be essential in the human diet or to be forms of something already on the list; adenine is often cited as the old B4 and para-aminobenzoic acid as B10. Other letters went the same way: vitamin H turned out to be biotin and vitamin G riboflavin. Names such as "vitamin B17" for amygdalin, a compound from apricot kernels that releases cyanide, have no scientific standing at all.
How are vitamins different from minerals?
Vitamins are organic compounds made by living things, while minerals are elements such as iron, calcium and zinc that come ultimately from soil and water. Vitamins can be broken down by heat, light and air during storage and cooking, while minerals cannot be destroyed, only lost into cooking water or bound up so that less is absorbed. Both are micronutrients needed in small amounts. How they fit alongside protein, carbohydrate, fat, fibre and water is set out in the post on types of nutrients.
Can an Indian vegetarian diet provide all 13 vitamins?
Mostly yes, with two regular gaps. A varied diet of cereals, pulses, vegetables, fruit, nuts and dairy covers A, E, K, C and most of the B vitamins. B12 is the weak point for vegetarians who take little dairy, and vitamin D depends more on sunlight and fortified foods than on the plate. Anyone starting out in nutrition learns this map first, and NNWA's Introduction to Nutrition course covers macronutrients, micronutrients, balanced plates and reading labels over two to three weeks at a beginner level, for 2,999 rupees, reduced from 4,999, with an NNWA certificate.
The whole list, briefly
The 13 vitamins are A, D, E and K, which are fat-soluble and stored, and C with the eight B vitamins, which are water-soluble and mostly not. Each has a chemical name, a job and a deficiency disease, and a varied Indian diet covers nearly all of them. The two worth watching are B12 and D.
Working through the list for your own plate
The list is easier to use than to memorise. Taken in this order it stops being a set of names.
Start with the two groups
Four that dissolve in fat and are stored, nine that dissolve in water and mostly are not. That split explains both how you take them in and how a dose goes wrong.
Learn each one by its job and its deficiency
Thiamin with nerves and heart muscle, vitamin C with collagen, vitamin K with clotting. The deficiency sign is the quickest handle on what the vitamin does.
Attach Indian foods to each
Amla and guava for C, drumstick leaves and carrot for A, milk and curd for riboflavin, pulses and greens for folate. A chemical name with no food attached is not usable advice.
Mark your own likely gaps
For most Indian vegetarians those are B12 and vitamin D. A varied plate covers nearly everything else without anyone counting.
Take any high dose to a doctor first
An amount far above the daily requirement needs a clear medical reason, and biotin supplements can distort thyroid and heart blood tests, so tell the laboratory if you take them.