Water soluble vitamin C is a type of vitamin. Vitamin C is an important micronutrient in our body. Water soluble vitamin c means it dissolves in water. The water soluble vitamin C are: ascorbic acid or simply just ascorbate,ascorbic acid or sodium ascorbate and acerola cherry powder
Water-soluble vitamins cannot be dissolved in water, although they can dissolve in fat or oil. For example, vitamin C is a water-soluble vitamin. Water soluble vitamins include ascorbic acid, niacin and pyridoxine.
vitamin that dissolves in water
Water soluble vitamins are found in non fat milk and fruit juices.
Water-soluble vitamins are ones that dissolve in water and are excreted by the body without being stored in the body. Water-soluble vitamins are available in food, mainly through milk and milk products.
water soluble
A vitamin that dissolves in water is called a water-soluble vitamin. The list of such vitamins includes vitamin A, E, B1, B2, B6 and C. These nutrients are crucial for the functioning of the body and cannot be produced by your body on its own. They are required at certain stages of life; they may not be good for you if they’re not present in your diet.
There are a lot of vitamins that can be taken orally. That’s the name in which I’ve chosen to refer to them in this article. Here is the list of water-soluble vitamins.
vitamin c water soluble
Nine water-soluble vitamins are found in the human diet:
Vitamin B1 (thiamine)
Vitamin B2 (riboflavin)
Vitamin B3 (niacin)
Vitamin B5 (pantothenic acid)
Vitamin B6
Vitamin B7 (biotin)
Vitamin B9
Vitamin B12 (cobalamin)
Vitamin C
Unlike the fat-soluble vitamins, water-soluble vitamins are generally not stored in the body. For this reason, you should try to get them regularly from your diet.
This article provides a detailed overview of the water-soluble vitamins — their functions, health benefits, dietary sources, recommended intake and more.
Thiamine (Vitamin B1)
Thiamine, also known as vitamin B1, was the first water-soluble vitamin to be described scientifically.
Types
Many forms of thiamine exist, including:
Thiamine pyrophosphate: Also known as thiamine diphosphate, thiamine pyrophosphate is the most abundant form of thiamine in your body. It is also the main form found in whole foods.
Thiamine triphosphate: This form is found in animal-sourced foods, but is less abundant than thiamine pyrophosphate. It is believed to represent less than 10% of the total thiamine found in animal tissues.
Thiamine mononitrate: A synthetic form of thiamine often added to animal feed or processed food.
Thiamine hydrochloride: The standard, synthetic form of thiamine used in supplements.
Role and Function
Like the other B vitamins, thiamine serves as a coenzyme in the body. This applies to all its active forms, but thiamine pyrophosphate is the most important one.
Coenzymes are small compounds that help enzymes trigger chemical reactions that otherwise wouldn’t happen on their own.
Thiamine is involved in many essential chemical reactions. For instance, it helps convert nutrients into energy and supports sugar formation.
Dietary Sources
The richest dietary sources of thiamine include nuts, seeds, whole grains, liver and pork.
The chart below shows the thiamine content of some of the best sources (1Trusted Source).
In contrast, fruits, vegetables and dairy products generally do not provide much thiamine.
Recommended Intake
The table below shows the recommended daily allowance (RDA) for thiamine.
The RDA for infants hasn’t been established. Instead, the table shows the adequate intake, marked with an asterisk. The adequate intake is like the RDA, but based on weaker evidence.
RDA (mg/day)
Infants 0–6 months 0.2*
7–12 months 0.3*
Children 1–3 years 0.5
4–8 years 0.6
9–13 years 0.9
Women 14–18 years 1.0
19+ years 1.1
Men 14+ years 1.2
Pregnancy 1.4
Lactation 1.4
*Adequate intake
Deficiency
Deficiency is uncommon, but high blood sugar levels may increase thiamine elimination via urine, raising its requirements and the risk of deficiency. In fact, thiamine levels may be reduced by 75–76% in people with type 1 and type 2 diabetes (2Trusted Source).
People with alcoholism are also at an increased risk for deficiency because of a poor diet and impaired thiamine absorption (3Trusted Source).
Serious deficiency may lead to disorders known as beriberi and Wernicke-Korsakoff syndrome.
These disorders are associated with a range of symptoms, including anorexia, weight loss, impaired neural function, mental problems, muscle weakness and heart enlargement.
Side Effects and Toxicity
Thiamine is considered safe. There are no reports of adverse effects after the intake of high amounts of thiamine from food or supplements.
This is partly because excess thiamine is quickly excreted from the body in urine.
As a result, the tolerable upper intake level for thiamine has not been established. However, this does not rule out possible symptoms of toxicity at very high intakes.
Benefits of Supplements
No good evidence shows that thiamine supplements benefit healthy people who get adequate amounts from their diets.
But for those with high blood sugar levels or a poor thiamine status, high-dose supplements may reduce blood sugar and blood pressure (4Trusted Source, 5Trusted Source).
Additionally, low thiamine intake has been associated with various other disorders, such as glaucoma, depression and fibromyalgia. However, more research is needed before strong conclusions can be made (6Trusted Source, 7Trusted Source, 8Trusted Source).
Summary of Thiamine
Thiamine, also known as vitamin B1, was the first B vitamin to be discovered.
Like the other B vitamins, thiamine acts as a coenzyme. It plays an essential role in many metabolic processes, including those that convert nutrients into energy.
The richest dietary sources of thiamine include liver, pork, seeds and whole-grain cereals. Deficiency is uncommon, but diabetes and excessive alcohol intake increase the risk. Serious deficiency may result in diseases such as beriberi and Wernicke-Korsakoff syndrome.
High-dose thiamine supplements do not seem to have any adverse effects and the tolerable upper intake level hasn’t been established. However, supplements do not appear to have any benefits for those who get adequate amounts from their diets.
Riboflavin (Vitamin B2)
Riboflavin is the only water-soluble vitamin used as a food coloring. In fact, it is named for its color — the Latin word flavus means “yellow.”
Types
In addition to riboflavin, dietary substances known as flavoproteins release riboflavin during digestion.
Two of the most common flavoproteins are flavin adenine dinucleotide and flavin mononucleotide. They are found in a wide range of foods.
Role and Function
Riboflavin functions as a coenzyme in various chemical reactions.
Like thiamine, it is involved in the conversion of nutrients into energy. It is also required in the conversion of vitamin B6 to its active form, and in the conversion of tryptophan to niacin (vitamin B3).
Dietary Sources
The chart below shows the riboflavin content of some of its richest dietary sources (1Trusted Source).
Yeast extract spread is also exceptionally rich in riboflavin, containing around 18 mg in every 100 grams. Other good sources of riboflavin include eggs, leafy vegetables, broccoli, milk, legumes, mushrooms and meat.
Additionally, riboflavin is often added to processed breakfast cereals and is used as a yellow-orange food coloring.
Recommended Intake
The table below shows the RDA or adequate intake for riboflavin. These values represent the daily intake sufficient to meet the requirements of most people.
RDA (mg/day)
Infants 0–6 months 0.3*
7–12 months 0.4*
Children 1–3 years 0.5
4–8 years 0.6
9–13 years 0.9
Women 14–18 years 1.0
19+ years 1.1
Men 14+ years 1.3
Pregnancy 1.4
Lactation 1.6
*Adequate intake
Deficiency
Riboflavin deficiency is very rare in developed countries. However, a poor diet, old age, lung diseases and alcoholism may increase the risk.
Severe deficiency results in a condition known as ariboflavinosis, which is characterized by a sore throat, inflamed tongue, anemia, as well as skin and eye problems.
It also impairs the metabolism of vitamin B6 and the conversion of tryptophan to niacin.
Side Effects and Toxicity
High intake of dietary or supplemental riboflavin has no known effects of toxicity.
Absorption becomes less efficient at higher doses. Also, very small amounts are stored in body tissues and excess riboflavin is flushed out of the body with urine.
As a result, the safe upper intake level of riboflavin has not been established.
Benefits of Supplements
In most cases, riboflavin supplements do not have any benefits for people who already get enough from food.
Yet, low-dose riboflavin supplements may potentially reduce blood pressure and lower the risk of heart disease in people who are genetically predisposed to them. It’s thought to do this by decreasing high homocysteine levels in those with two copies of the gene MTHFR 677TT (9Trusted Source, 10Trusted Source, 11Trusted Source).
Higher doses of riboflavin, such as 200 mg twice a day, may also reduce migraines (12Trusted Source, 13Trusted Source).
Summary of Riboflavin
Riboflavin, also known vitamin B2, is a coenzyme with various essential functions. For instance, it is required for converting nutrients to energy.
Found in various foods, its richest sources include liver, meat, dairy products, eggs, leafy vegetables, almonds and legumes.
Deficiency is virtually unknown among healthy people in Western countries, although diseases and poor lifestyle habits may increase the risk.
High-dose riboflavin supplements are not known to have any adverse effects, but they usually only benefit those who are deficient. However, evidence suggests they may reduce migraines or lower the risk of heart disease in genetically susceptible people.
Niacin (Vitamin B3)
Niacin, also known as vitamin B3, is the only B vitamin your body can produce from another nutrient — the amino acid tryptophan.
Types
Niacin is a group of related nutrients. The most common forms are:
Nicotinic acid: The most common form in supplements. Also found in both plant- and animal-sourced foods. High-dose nicotinic acid supplements may cause a condition called niacin flush.
Nicotinamide (niacinamide): Found in supplements and foods.
The compound nicotinamide riboside also has vitamin B3 activity. It is found in trace amounts in whey protein and baker’s yeast (14Trusted Source, 15Trusted Source, 16Trusted Source).
Role and Function
All dietary forms of niacin are eventually converted into nicotinamide adenine dinucleotide (NAD+) or nicotinamide adenine dinucleotide phosphate (NADP+), which act as coenzymes.
Like the other B vitamins, it functions as a coenzyme in the body, playing an essential role in cellular function and acting as an antioxidant.
One of its most important roles is to drive a metabolic process known as glycolysis, the extraction of energy from glucose (sugar).
Dietary Sources
Niacin is found in both plants and animals. The chart below shows the niacin content of a few of its best sources (1Trusted Source).
Yeast extract spread is exceptionally rich in niacin, providing around 128 mg in every 100 grams.
Other good sources include fish, chicken, eggs, dairy products and mushrooms. Niacin is also added to breakfast cereals and flour.
Additionally, your body can synthesize niacin from the amino acid tryptophan. Scientists have estimated that 60 mg of tryptophan can be used to create 1 mg of niacin (17Trusted Source).
Recommended Intake
The table below shows the RDA or adequate intake for niacin. These values are the estimated amount of niacin that most people (97.5%) need to get from their diets every day.
It also shows the tolerable upper intake limit (UL), which is the highest daily intake considered safe for most people.
RDA (mg/day) UL (mg/day)
Infants 0–6 months 2* –
7–12 months 4* –
Children 1–3 years 6 10
4–8 years 8 15
9–13 years 12 20
Women 14+ years 14 30
Men 14+ years 16 30
Pregnancy 18 30–35
Lactation 17 30–35
*Adequate intake
Deficiency
Niacin deficiency, known as pellagra, is uncommon in developed countries.
The main symptoms of pellagra include inflamed skin, mouth sores, diarrhea, insomnia and dementia. Like all deficiency diseases, it is fatal without treatment.
Fortunately, you can easily get all the niacin you need from a varied diet.
Deficiency is much more common in developing countries where people commonly follow diets that lack diversity.
Cereal grains are especially low in available niacin, since most of it is bound to fiber in the form of niacytin.
However, your body can synthesize it from the amino acid tryptophan. As a result, severe niacin deficiency can often be avoided on a high-protein diet (17Trusted Source).
Side Effects and Toxicity
Naturally occurring niacin from food does not appear to have any adverse effects.
However, high supplemental doses of niacin may cause niacin flush, nausea, vomiting, stomach irritation and liver damage.
Niacin flush is a side effect of immediate-release nicotinic acid supplements. It is characterized by a flush in the face, neck, arms and chest (18Trusted Source, 19Trusted Source).
Liver damage is associated with the long-term use of very high doses (3–9 grams per day) of sustained-release or slow-release nicotinic acid (20Trusted Source, 21Trusted Source, 22Trusted Source).
Additionally, taking niacin supplements for a long time may increase insulin resistance and raise blood sugar levels (23Trusted Source, 24Trusted Source).
Nicotinic acid may also increase the circulating levels of uric acid, worsening symptoms in people who are predisposed to gout (25Trusted Source).
Benefits of Supplements
Nicotinic acid supplements at doses ranging from 1,300–2,000 mg per day are commonly used to normalize blood lipid levels (26Trusted Source, 27Trusted Source).
They bring down high levels of “bad” low-density-lipoprotein (LDL) cholesterol, while raising levels of “good” high-density-lipoprotein (HDL) cholesterol when they are low. Triglyceride levels may also drop in those taking supplements.
Some studies also suggest nicotinic acid reduces heart disease risk, but its benefits are controversial and study results have been inconsistent (28Trusted Source, 29Trusted Source).
Preliminary evidence also indicates that niacin supplements may improve cognition, but further studies are needed before strong claims can be made (30Trusted Source).
Summary of Niacin
Niacin, also known as vitamin B3, is a group of two related compounds — niacinamide and nicotinic acid. They serve many vital functions in the body.
Niacin is found in many different foods, such as liver, fish, poultry, eggs, dairy products, sunflower seeds and peanuts, to name few. Additionally, it is commonly added to processed food like flour and breakfast cereals.
Deficiency is rare in Western nations. People who eat low-protein diets that lack diversity are at an increased risk.
High-dose nicotinic acid supplements are commonly used to normalize blood lipid levels, although some scientists doubt the vitamin’s benefits for heart health.
But supplements may also have some negative side effects, such as liver damage, reduced insulin sensitivity and niacin flush.
Pantothenic Acid (Vitamin B5)
Pantothenic acid is found in virtually all food. Appropriately, its name is derived from the Greek word pantothen, which means “from every side.”
Types
There are multiple forms of pantothenic acid or compounds that release the active form of the vitamin when digested. In addition to free pantothenic acid, these include:
Coenzyme A: A common source of this vitamin in foods. It releases pantothenic acid in the digestive tract.
Acyl carrier protein: Like coenzyme A, acyl carrier protein is found in foods and releases pantothenic acid during digestion.
Calcium pantothenate: The most common form of pantothenic acid in supplements.
Panthenol: Another form of pantothenic acid often used in supplements.
Role and Function
Pantothenic acid plays a key role in a wide range of metabolic functions.
It is required for the formation of coenzyme A, which is necessary for the synthesis of fatty acids, amino acids, steroid hormones, neurotransmitters and various other important compounds.
Dietary Sources
Pantothenic acid is found in virtually all food.
The chart below shows some of its best dietary sources (1Trusted Source).
Other rich sources include yeast extract spread, shiitake mushrooms, caviar, kidneys, chicken, beef and egg yolks.
Several plant foods are also good sources. In addition to those mentioned above, these include root vegetables, whole grains, tomatoes and broccoli.
Like many other B vitamins, pantothenic acid is often added to breakfast cereals.
Recommended Intake
The table below shows the adequate intake (AI) of pantothenic acid for most people. The RDA has not been established.
AI (mg/day)
Infants 0–6 months 1.7
7–12 months 1.8
Children 1–3 years 2
4–8 years 3
9–13 years 4
Adolescents 14–18 years 5
Adults 19+ years 5
Pregnancy 6
Lactation 7
Deficiency
Pantothenic acid deficiency is rare in industrialized countries. In fact, this vitamin is so widespread in foods that deficiency is virtually unheard of, except in severe malnutrition.
However, its requirements may be higher in people with diabetes and those who regularly consume excessive amounts of alcohol.
Studies in animals show that pantothenic acid deficiency has an adverse impact on most organ systems. It is associated with numerous symptoms, including numbness, irritability, sleep disturbances, restlessness and digestive problems (31Trusted Source).
Side Effects and Toxicity
Pantothenic acid does not appear to have any adverse effects at high doses. The tolerable upper limit has not been established.
However, large doses like 10 grams per day may cause digestive discomfort and diarrhea.
In mice, the lethal dose was estimated to be around 4.5 grams for each pound of body weight (10 grams per kg), an amount equivalent to 318 grams for a 154-pound (70-kg) human (32Trusted Source).
Benefits of Supplements
Studies have not provided any good evidence of benefits from pantothenic acid supplements in people who get adequate amounts from their diets.
While people take supplements to treat various disorders, including arthritis, dry eyes and skin irritation, there is no strong evidence for its effectiveness in the treatment of any of these disorders (33).
Summary of Pantothenic Acid
Pantothenic acid, also known as vitamin B5, plays various important roles in metabolism.
Almost all food contains this vitamin. The best sources include liver, sunflower seeds, mushrooms, root vegetables and whole grains.
Since pantothenic acid is so widespread in foods, deficiency is virtually unknown and is usually only associated with severe malnutrition.
Supplements are safe and do not have any adverse effects. However, very high doses may cause diarrhea and other digestive issues.
Although some people regularly take pantothenic acid supplements, there is currently no strong evidence for their effectiveness in the treatment of diseases in those who get adequate amounts from food.
Vitamin B6
Vitamin B6 is a group of nutrients that are required for the synthesis of pyridoxal phosphate, a coenzyme involved in more than 100 different metabolic processes.
Types
Like the other B vitamins, vitamin B6 is a family of related compounds, such as:
Pyridoxine: This form is found in fruits, vegetables and grains, as well as supplements. Processed foods may also contain added pyridoxine.
Pyridoxamine: Used until recently in dietary supplements in the US. However, the FDA now considers pyridoxamine a pharmaceutical drug. Pyridoxamine phosphate is a common form of vitamin B6 in animal-sourced foods.
Pyridoxal: Pyridoxal phosphate is the main type of vitamin B6 in animal-sourced foods.
In the liver, all dietary forms of vitamin B6 are converted into pyridoxal 5-phosphate, the active form of the vitamin.
Role and Function
Like other B vitamins, vitamin B6 acts as a coenzyme in numerous chemical reactions.
It is involved in red blood cell formation as well as energy and amino acid metabolism. It is also required for the release of glucose (sugar) from glycogen, the molecule the body uses to store carbs.
Vitamin B6 also supports the formation of white blood cells and helps the body synthesize several neurotransmitters.
Dietary Sources
Vitamin B6 is found in a wide variety of foods. The chart below shows some of its richest sources and their content (1Trusted Source).
Other good sources include tuna, pork, turkey, bananas, chickpeas and potatoes. Vitamin B6 is also added to breakfast cereals and soy-based meat substitutes.
The availability of this vitamin is generally higher in animal-sourced foods, compared to plant foods (34Trusted Source).
Recommended Intake
The table below shows the RDA for vitamin B6. The RDA is the daily intake estimated to be sufficient for most people.
The RDA hasn’t been established for infants, so the adequate intake (AI) is presented instead.
RDA (mg/day) UL (mg/day)
Infants 0–6 months 0.1* –
7–12 months 0.3* –
Children 1–3 years 0.5 30
4–8 years 0.6 40
9–13 years 1.0 60
Women 14–18 years 1.2 80
19–50 years 1.3 100
51+ years 1.5 100
Men 14–18 years 1.3 80
19–50 years 1.3 100
51+ years 1.7 100
Pregnancy 1.9 80–100
Lactation 2.0 80–100
*Adequate intake
Deficiency
Vitamin B6 deficiency is rare. People with alcoholism are at the greatest risk (35Trusted Source).
The main symptoms include anemia, skin rashes, convulsions, confusion and depression.
Deficiency has also been associated with an increased risk of cancer (36Trusted Source, 37Trusted Source).
Side Effects and Toxicity
Naturally occurring vitamin B6 from food does not seem to have any adverse effects.
In contrast, very large supplemental doses of pyridoxine — 2,000 mg per day or more — are linked to sensory nerve damage and skin lesions (38Trusted Source).
High intake of pyridoxine supplements may also suppress milk production in breastfeeding women (39Trusted Source).
Benefits of Supplements
Large doses of pyridoxine have been used to treat carpal tunnel syndrome and premenstrual syndrome.
However, its benefits are controversial. No strong evidence proves that pyridoxine supplements are an effective treatment for these conditions (40Trusted Source, 41Trusted Source).
Because of the adverse health effects of high-dose pyridoxine supplements, they should only be taken under medical supervision.
Summary of Vitamin B6
Vitamin B6 is a group of nutrients that are required for the formation of pyridoxal phosphate, a coenzyme that plays a vital role in numerous metabolic pathways.
The richest dietary sources are liver, salmon, sunflower seeds and pistachio nuts, to name a few.
Deficiency is rare, although regularly drinking high amounts of alcohol may raise the risk.
High supplemental doses may cause nerve damage and skin lesions, but getting vitamin B6 from food doesn’t appear to have any negative effects.
While adequate vitamin B6 intake is healthy, no good evidence demonstrates that vitamin B6 supplements are useful in the treatment of diseases.
Biotin (Vitamin B7)
People often take biotin supplements to nourish their hair, nails and skin, although strong evidence for these benefits is lacking. In fact, it was historically called vitamin H after the German word haut, meaning “skin” (42Trusted Source).
Types
Biotin is either found in its free form or bound to proteins.
When proteins that contain biotin are digested they release a compound called biocytin. The digestive enzyme biotinidase then breaks biocytin into free biotin and lysine, an amino acid.
Role and Function
Same as all B vitamins, biotin functions as a coenzyme. It is required for the function of five carboxylases, enzymes involved in several fundamental metabolic processes.
For instance, biotin serves an essential role in fatty acid synthesis, glucose formation and amino acid metabolism.
Dietary Sources
Compared to the other B vitamins, biotin doesn’t have as much research behind its content in food.
Animal-sourced foods rich in biotin include organ meats, fish, meat, egg yolk and dairy products. Good plant sources include legumes, leafy greens, cauliflower, mushrooms and nuts.
Your gut microbiota also produces small amounts of biotin.
Recommended Intake
The table below shows the adequate intake (AI) for biotin. The AI is similar to the RDA, but is based on weaker research.
AI (mcg/day)
Infants 0–6 months 5
7–12 months 6
Children 1–3 years 8
4–8 years 12
9–13 years 20
Adolescents 14–18 years 25
Adults 19+ years 30
Pregnancy 30
Lactation 35
Deficiency
Biotin deficiency is relatively uncommon.
The risk is greatest among infants who are fed formula low in biotin, people taking antiepileptic medications, infants with Leiner’s disease or people who are genetically predisposed to deficiency (43Trusted Source, 44Trusted Source).
Untreated biotin deficiency can cause neurological symptoms, such as seizures, intellectual disability and loss of muscle coordination (45Trusted Source).
Deficiency has also been reported in animals fed high amounts of raw egg whites. Egg whites contain a protein called avidin, which prevents the absorption of biotin (46Trusted Source).
Side Effects and Toxicity
Biotin does not have any known adverse effects at high doses and the tolerable upper limit has not been established.
Benefits of Supplements
Limited evidence suggests that biotin supplements may improve health in those who otherwise get adequate amounts from their diets.
For instance, studies suggest biotin may improve symptoms in people with multiple sclerosis (MS) (47Trusted Source, 48Trusted Source).
Observational studies also indicate that biotin supplements may improve brittle nails in women. However, higher quality studies are needed before any claims can be made (49Trusted Source, 50Trusted Source).
Summary of Biotin
Biotin, also known as vitamin B7, is a coenzyme required for many key metabolic processes.
It is found in a wide range of foods. Good sources include organ meats, egg yolk, meat, legumes, cauliflower, mushrooms and nuts.
Deficiency is uncommon and adverse effects are unknown, even at high supplemental doses. Further studies need to establish the tolerable upper intake level.
Limited evidence supports the use of biotin supplements among people who already get adequate amounts from their diets. However, a few studies suggest they may improve the symptoms of MS and strengthen brittle nails.
Vitamin B9
Vitamin B9 was first discovered in yeast, but later isolated from spinach leaves. For this reason, it was given the names folic acid or folate, words derived from the Latin word folium, meaning “leaf.”
Types
Vitamin B9 comes in several different forms, including:
Folate: A family of vitamin B9 compounds that naturally occurs in foods.
Folic acid: A synthetic form commonly added to processed foods or sold as a supplement. Some scientists are concerned that high-dose folic acid supplements may cause harm.
L-methylfolate: Also known as 5-methyltetrahydrofolate, L-methylfolate is the active form of vitamin B9 in the body. As a supplement, it is thought to be healthier than folic acid.
Role and Function
Vitamin B9 acts as a coenzyme and is essential for cell growth, DNA formation and amino acid metabolism.
It is very important during periods of rapid cell division and growth, such as in infancy and pregnancy.
Additionally, it is required for the formation of red and white blood cells, so deficiency may lead to anemia.
Dietary Sources
The chart below presents a few foods that are great sources of vitamin B9 (1Trusted Source).
Other good sources include leafy greens, legumes, sunflower seeds and asparagus. Yeast extract spread is exceptionally rich in vitamin B9, providing around 3,786 mcg per 100 grams.
Folic acid is also frequently added to processed food products.
Recommended Intake
The table below shows the recommended daily allowance (RDA) for vitamin B9. It also presents the daily tolerable upper limit (UL), which is the amount considered safe for most people.
The RDA for infants hasn’t been established. Instead, the table shows the adequate intake values.
RDA (mcg/day) UL (mcg/day)
Infants 0–6 months 65* –
7–12 months 80* –
Children 1–3 years 150 300
4–8 years 200 400
9–13 years 300 600
14–18 years 400 800
Adults 19+ years 400 1,000
Pregnancy 600 800–1,000
Lactation 500 800–1,000
*Adequate intake
Deficiency
Vitamin B9 deficiency rarely occurs on its own. It is usually associated with other nutrient deficiencies and a poor diet.
Anemia is one of the classic symptoms of vitamin B9 deficiency. It is indistinguishable from the anemia associated with vitamin B12 deficiency (51Trusted Source).
Lack of vitamin B9 may also lead to birth defects of the brain or neural chord, collectively known as neural tube defects (52Trusted Source).
Side Effects and Toxicity
No serious adverse effects of high vitamin B9 intake have been reported.
Yet, studies show that high-dose supplements may mask vitamin B12 deficiency. Some even suggest that they may worsen the neurological damage associated with vitamin B12 deficiency (53Trusted Source, 54Trusted Source).
Additionally, some scientists are concerned that a high intake of folic acid — a synthetic form of vitamin B9 — may cause health problems.
Benefits of Supplements
There is not much evidence that folic acid supplements benefit healthy people who are following a balanced diet.
A few studies suggest that supplements may reduce the risk of heart disease, improve blood sugar control and slightly reduce the symptoms of depression (55Trusted Source, 56Trusted Source, 57Trusted Source, 58Trusted Source).
However, the benefits of taking vitamin B9 supplements may only be seen in those who are low in the vitamin to begin with.
Summary of Vitamin B9
Like all other B vitamins, vitamin B9 acts as a coenzyme. It is essential for cell growth and various key metabolic functions.
It is found in both plants and animals. Rich sources include liver, legumes and leafy greens.
Deficiency in vitamin B9 is uncommon. The main symptom is anemia, but in pregnant women, low levels also raise the risk of birth defects. High intake doesn’t have any serious adverse effects.
For those who get enough vitamin B9 from their diet, the benefits of supplements are unclear. But studies suggest they may reduce the risk of heart disease and lower blood sugar levels.
Vitamin B12 (Cobalamin)
Vitamin B12 is the only vitamin that contains a metallic element, namely cobalt. For this reason, it is often referred to as cobalamin.
Types
There are four main types of vitamin B12 — cyanocobalamin, hydroxocobalamin, adenosylcobalamin and methylcobalamin (59Trusted Source).
All of them can be found in supplements, although cyanocobalamin is the most common. It is considered ideal for supplements due to its stability, but is only found in trace amounts in food.
Hydroxocobalamin is the most common naturally occurring form of vitamin B12, and is widely found in animal-sourced foods.
The other natural forms methylcobalamin and adenosylcobalamin have become popular as supplements in recent years.
Role and Function
Like all other B vitamins, vitamin B12 acts as a coenzyme.
Adequate intake helps maintain brain function and development, neurological function, and the production of red blood cells.
It is also required for converting protein and fat into energy and is essential for cell division and DNA synthesis.
Dietary Sources
Animal-sourced foods are virtually the only dietary sources of vitamin B12. These include meat, dairy products, seafood and eggs.
The chart below shows some of its richest sources and their content (1Trusted Source).
Other rich sources include other types of liver, heart, octopus, oysters, herring and tuna.
However, tempeh and a few algae, such as nori seaweed, may also contain small amounts of vitamin B12. Whether these foods can provide sufficient amounts on their own is a matter of debate (60Trusted Source, 61Trusted Source, 62Trusted Source).
Other algae, like spirulina, contain pseudovitamin B12, a group of compounds that are similar to vitamin B12, but unusable by the body (63Trusted Source).
Recommended Intake
The table below shows the RDA for vitamin B12. As usual, the RDA hasn’t been established for infants, so the adequate intake (AI) is presented instead.
RDA (mcg/day)
Infants 0–6 months 0.4*
7–12 months 0.5*
Children 1–3 years 0.9
4–8 years 1.2
9–13 years 1.8
Adolescents 14–18 years 2.4
Adults 19+ years 2.4
Pregnancy 2.6
Lactation 2.8
*Adequate intake
Deficiency
Vitamin B12 is stored in the liver, so even if you aren’t getting enough of it, it may take a long time for deficiency symptoms to develop.
Those who are at the greatest risk of deficiency are those who never or rarely eat animal-sourced foods. This includes vegetarians and vegans (64Trusted Source).
Deficiency may also develop in older people. In fact, many require regular vitamin B12 injections.
Vitamin B12 absorption depends on a protein produced by the stomach called intrinsic factor. As people age, the formation of intrinsic factor may reduce or stop altogether (65Trusted Source).
Other risk groups include those who have had weight loss surgery or suffer from Crohn’s disease or celiac disease (66Trusted Source, 67Trusted Source, 68Trusted Source, 69Trusted Source).
Deficiency may cause various health problems, such as anemia, appetite loss, sore tongue, neurological problems and dementia (70Trusted Source).
Side Effects and Toxicity
Only a small proportion of vitamin B12 can be absorbed from the digestive tract. The amount absorbed depends on the production of intrinsic factor in the stomach.
As a result, no adverse effects have been linked with high intake of vitamin B12 in healthy people. The tolerable upper intake level has not been established.
Benefits of Supplements
While vitamin B12 supplements benefit people at risk of deficiency, less is known about their effects among those who get adequate amounts from their diets.
One small study suggests that taking 1,000 mcg per day may improve verbal learning in people recovering from strokes, but more research is needed (71Trusted Source).
Additionally, injections of hydroxocobalamin are used to treat cyanide poisoning, usually in combination with sodium thiosulfate (72Trusted Source).
Summary of Vitamin B12
Vitamin B12 functions as a coenzyme and plays a vital role in many metabolic pathways. It also helps maintain neurological function and the formation of red blood cells.
It is found in virtually all animal-sourced foods, but is absent from plant foods.
As a result, vegans are at risk of deficiency or poor vitamin B12 status. Older people are also at risk because of impaired absorption. Anemia and impaired neurological function are classic deficiency symptoms.
High supplemental intake doesn’t have any known adverse effects. No strong evidence shows that they have benefits either, at least not in those who get adequate amounts from their diets.