What are essential vitamins?

Essential vitamins are organic compounds needed for the normal functioning of the human body. Because the body cannot synthesize them sufficiently, they must be obtained through diet or synthetic sources. There are 13 essential vitamins, divided into water-soluble (vitamin C and eight B-complex vitamins) and fat-soluble vitamins (vitamins A, D, E, and K). Water-soluble vitamins are generally not stored and must be consumed regularly, while fat-soluble vitamins are stored in the liver and fatty tissues. Each vitamin has specific roles, such as vitamin A for vision, B vitamins for energy metabolism, vitamin C as an antioxidant, and vitamin D for bone health.

Why does the human body need vitamins?

Vitamins are essential for the human body because they facilitate metabolic processes and assist in energy-yielding reactions. Since the body cannot synthesize them in sufficient amounts, they must be obtained through diet or synthetic sources. Vitamins are micronutrients that are not energy sources, but they are needed in small amounts for survival. There are 13 essential vitamins, divided into water-soluble (vitamin C and eight B-complex vitamins) and fat-soluble vitamins (vitamins A, D, E, and K). Each plays a key role, from vision and immune function (Vitamin A) to blood clotting (Vitamin K). Deficiencies in any of these vitamins can lead to specific health problems.

How do we get essential vitamins in our diet?

Essential vitamins, crucial for normal growth and health, can't be sufficiently synthesized by the body, so they must be obtained through diet or synthetic sources. Vitamins are found in all living organisms, but they are not equally distributed in nature. Both plants and animals are important natural vitamin sources for humans. Since vitamins are not equally distributed in foodstuffs, the more restricted the diet of an individual, the more likely it is that he will lack adequate amounts of one or more vitamins. The 13 vitamins that humans need are divided into water-soluble (vitamin C and the B-complex vitamins) and fat-soluble vitamins (vitamins A, D, E, and K).

What are the main types of vitamins (such as water-soluble and fat-soluble)?

Vitamins are essential nutrients that the body requires in small quantities for normal health and growth. Because the body cannot synthesize them in sufficient amounts, they must be obtained through diet or synthetic sources. Vitamins are divided into two main types: water-soluble and fat-soluble. Water-soluble vitamins, including vitamin C and the B vitamins (such as thiamin, riboflavin, niacin, vitamin B6, vitamin B12, folic acid, pantothenic acid, and biotin), dissolve in water, influencing their absorption, excretion, and storage in the body. Fat-soluble vitamins (A, D, E, and K) are structurally related and require bile salts for efficient absorption in the intestine. They are transported by lymph to the blood, stored in the liver and fatty tissues, and excessive intake can lead to toxicity.

What are some symptoms of vitamin deficiencies?

Vitamin deficiencies can result in a range of symptoms, depending on the specific vitamin lacking. Vitamin A deficiency can cause night blindness and, if severe, may lead to xerophthalmia, a condition that can result in blindness. A deficiency in vitamin C can cause scurvy, with symptoms including bleeding gums, slow wound healing, and internal bleeding. Thiamin (vitamin B1) deficiency can lead to nerve and heart muscle impairment. Niacin deficiency can cause skin lesions, nervous system issues, and gastrointestinal problems. Vitamin D deficiency can result in weakened bones, known as rickets in children and osteomalacia in adults. It's important to note that multiple vitamin deficiencies can occur simultaneously.

How can a balanced diet help prevent vitamin deficiencies and keep us healthy?

A balanced diet is crucial for preventing vitamin deficiencies and maintaining overall health. Essential vitamins cannot be synthesized by the body in sufficient amounts and must be obtained through diet or synthetic sources. These vitamins facilitate metabolic processes, support growth, and ensure normal bodily functions. Inadequate intake of vitamins can lead to deficiency diseases, with symptoms ranging from mild to severe. A balanced diet that includes a variety of foods can help ensure you get enough of each essential vitamin , reducing the risk of deficiencies and promoting optimal health.

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What are essential vitamins?
Essential vitamins are organic compounds needed for the normal functioning of the human body. Because the body cannot synthesize them sufficiently, they must be obtained through diet or synthetic sources.

There are 13 essential vitamins, divided into water-soluble (vitamin C and eight B-complex vitamins) and fat-soluble vitamins (vitamins A, D, E, and K). Water-soluble vitamins are generally not stored and must be consumed regularly, while fat-soluble vitamins are stored in the liver and fatty tissues. Each vitamin has specific roles, such as vitamin A for vision, B vitamins for energy metabolism, vitamin C as an antioxidant, and vitamin D for bone health.
4 Britannica Sources
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Why does the human body need vitamins?
Vitamins are essential for the human body because they facilitate metabolic processes and assist in energy-yielding reactions. Since the body cannot synthesize them in sufficient amounts, they must be obtained through diet or synthetic sources.

Vitamins are micronutrients that are not energy sources, but they are needed in small amounts for survival. There are 13 essential vitamins, divided into water-soluble (vitamin C and eight B-complex vitamins) and fat-soluble vitamins (vitamins A, D, E, and K). Each plays a key role, from vision and immune function (Vitamin A) to blood clotting (Vitamin K). Deficiencies in any of these vitamins can lead to specific health problems.
4 Britannica Sources
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How do we get essential vitamins in our diet?
Essential vitamins, crucial for normal growth and health, can't be sufficiently synthesized by the body, so they must be obtained through diet or synthetic sources.

Vitamins are found in all living organisms, but they are not equally distributed in nature. Both plants and animals are important natural vitamin sources for humans. Since vitamins are not equally distributed in foodstuffs, the more restricted the diet of an individual, the more likely it is that he will lack adequate amounts of one or more vitamins.

The 13 vitamins that humans need are divided into water-soluble (vitamin C and the B-complex vitamins) and fat-soluble vitamins (vitamins A, D, E, and K).
3 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
What are the main types of vitamins (such as water-soluble and fat-soluble)?
Vitamins are essential nutrients that the body requires in small quantities for normal health and growth. Because the body cannot synthesize them in sufficient amounts, they must be obtained through diet or synthetic sources. Vitamins are divided into two main types: water-soluble and fat-soluble.

Water-soluble vitamins, including vitamin C and the B vitamins (such as thiamin, riboflavin, niacin, vitamin B6, vitamin B12, folic acid, pantothenic acid, and biotin), dissolve in water, influencing their absorption, excretion, and storage in the body.

Fat-soluble vitamins (A, D, E, and K) are structurally related and require bile salts for efficient absorption in the intestine. They are transported by lymph to the blood, stored in the liver and fatty tissues, and excessive intake can lead to toxicity.
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1. essential vitamins
2. vitamin: Basic properties
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What are some symptoms of vitamin deficiencies?
Vitamin deficiencies can result in a range of symptoms, depending on the specific vitamin lacking. Vitamin A deficiency can cause night blindness and, if severe, may lead to xerophthalmia, a condition that can result in blindness. A deficiency in vitamin C can cause scurvy, with symptoms including bleeding gums, slow wound healing, and internal bleeding. Thiamin (vitamin B1) deficiency can lead to nerve and heart muscle impairment. Niacin deficiency can cause skin lesions, nervous system issues, and gastrointestinal problems. Vitamin D deficiency can result in weakened bones, known as rickets in children and osteomalacia in adults. It's important to note that multiple vitamin deficiencies can occur simultaneously.
6 Britannica Sources
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How can a balanced diet help prevent vitamin deficiencies and keep us healthy?
A balanced diet is crucial for preventing vitamin deficiencies and maintaining overall health. Essential vitamins cannot be synthesized by the body in sufficient amounts and must be obtained through diet or synthetic sources. These vitamins facilitate metabolic processes, support growth, and ensure normal bodily functions.

Inadequate intake of vitamins can lead to deficiency diseases, with symptoms ranging from mild to severe. A balanced diet that includes a variety of foods can help ensure you get enough of each essential vitamin, reducing the risk of deficiencies and promoting optimal health.
4 Britannica Sources
Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

There are 13 essential vitamins necessary for the normal health and growth of the human body. Given that vitamins cannot usually be synthesized by the body in sufficient amounts, they must be obtained from the diet or from some synthetic source. They are traditionally separated into two groups: water-soluble vitamins and fat-soluble vitamins. The following table lists the common and chemical names of the essential vitamins, along with their main biological functions and deficiency symptoms.

Water-soluble vitamins
vitamin	alternative names/forms	biological function	symptoms of deficiency
thiamin	vitamin B₁	component of a coenzyme in carbohydrate metabolism; supports normal nerve function	impairment of the nerves and heart muscle wasting
riboflavin	vitamin B₂	component of coenzymes required for energy production and lipid, vitamin, mineral, and drug metabolism; antioxidant	inflammation of the skin, tongue, and lips; ocular disturbances; nervous symptoms
niacin	nicotinic acid, nicotinamide	component of coenzymes used broadly in cellular metabolism, oxidation of fuel molecules, and fatty acid and steroid synthesis	skin lesions, gastrointestinal disturbances, nervous symptoms
vitamin B₆	pyridoxine, pyridoxal, pyridoxamine	component of coenzymes in metabolism of amino acids and other nitrogen-containing compounds; synthesis of hemoglobin, neurotransmitters; regulation of blood glucose levels	dermatitis, mental depression, confusion, convulsions, anemia
folic acid	folate, folacin, pteroylglutamic acid	component of coenzymes in DNA synthesis, metabolism of amino acids; required for cell division, maturation of red blood cells	impaired formation of red blood cells, weakness, irritability, headache, palpitations, inflammation of mouth, neural tube defects in fetus
vitamin B₁₂	cobalamin, cyanocobalamin	cofactor for enzymes in metabolism of amino acids (including folic acid) and fatty acids; required for new cell synthesis, normal blood formation, and neurological function	smoothness of the tongue, gastrointestinal disturbances, nervous symptoms
pantothenic acid		as component of coenzyme A, essential for metabolism of carbohydrate, protein, and fat; cofactor for elongation of fatty acids	weakness, gastrointestinal disturbances, nervous symptoms, fatigue, sleep disturbances, restlessness, nausea
biotin		cofactor in carbohydrate, fatty acid, and amino acid metabolism	dermatitis, hair loss, conjunctivitis, neurological symptoms
vitamin C	ascorbic acid	antioxidant; synthesis of collagen, carnitine, amino acids, and hormones; immune function; enhances absorption of nonheme iron (from plant foods)	swollen and bleeding gums, soreness and stiffness of the joints and lower extremities, bleeding under the skin and in deep tissues, slow wound healing, anemia

Fat-soluble vitamins
vitamin	alternative names/forms	biological function	symptoms of deficiency
vitamin A	retinol, retinal, retinoic acid, beta-carotene (plant version)	normal vision, integrity of epithelial cells (mucous membranes and skin), reproduction, embryonic development, growth, immune response	ocular disturbances leading to blindness, growth retardation, dry skin, diarrhea, vulnerability to infection (see vitamin A deficiency)
vitamin D	calciferol, calatriol (1,25-dihydroxy vitamin D₁ or vitamin D hormone), cholecalciferol (D₃; plant version), ergocalciferol (D₂; animal version)	maintenance of blood calcium and phosphorus levels, proper mineralization of bones	defective bone growth in children, soft bones in adults deficiency
vitamin E	alpha-tocopherol, tocopherol, tocotrienol	antioxidant; interruption of free radical chain reactions; protection of polyunsaturated fatty acids, cell membranes	peripheral neuropathy, breakdown of red blood cells
vitamin K	phylloquinone, menaquinone, menadione, naphthoquinone	synthesis of proteins involved in blood coagulation and bone metabolism	impaired clotting of the blood and internal bleeding

The Editors of Encyclopaedia Britannica This article was most recently revised and updated by Melissa Petruzzello.

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