Vitamins are often classified according to their solubility. Most of them dissolve in water and are called water-soluble vitamins. On the contrary, there are only four fat-soluble vitamins because they dissolve in oil.
The B vitamins are soluble in water and are found through the diet. They are the following:
- Vitamin B1 (thiamine)
- Vitamin B2 (riboflavin)
- Vitamin B3 (niacin)
- Vitamin B5 (pantothenic acid)
- Vitamin B6 (pyridoxine)
- Vitamin B7 (biotin)
- Vitamin B9 (folate)
- Vitamin B12 (cobalamin)
Unlike fat-soluble vitamins, water-soluble vitamins are generally not stored in the body. For this reason, you should try to obtain them regularly through diet.
Discover the guide to the 8 water-soluble complex vitamins , how they work, dietary sources, the recommended intake and their possible side effects.
Definitive guide to water-soluble vitamins
1.Vitamin B1 or Thiamine
Like other B vitamins, thiamine serves as a coenzyme in the body. Coenzymes are small compounds that help enzymes trigger chemical reactions that would not otherwise occur on their own. It helps convert nutrients into energy and sugar formation.
Functions of Thiamine
1.2 Sources and recommended intake
The richest dietary sources of thiamine include nuts, seeds, whole grains, liver and pork. In contrast, fruits, vegetables and dairy products generally do not provide much thiamine.
The recommended daily intake ranges from 1 to 1.2 milligrams (mg) for adults.
1.3 Deficiency and side effects
Deficiency is rare, but high blood sugar can increase the elimination of thiamine through urine, raising the risk of deficiency. In fact, thiamine levels can be reduced by 75-76% in people with type 1 and type 2 diabetes.
People with alcohol problems also have a higher risk of lacking this type of vitamin. There are no reports of adverse effects from ingesting high amounts of thiamine from food or supplements.
2.Vitamin B2 or Riboflavin
Riboflavin is the only water-soluble vitamin used as a food coloring. It is involved in the conversion of nutrients into energy. It is also necessary for the conversion of vitamin B6 to its active form, and in the transformation of tryptophan into niacin.
2.2 Source and intake
Good sources of riboflavin include eggs, broccoli, milk, legumes, mushrooms and meat. Also the yeast extract is exceptionally rich in riboflavin. The intake for adults ranges from 1 to 1.3 milligrams.
2.3 Deficiency and side effects
The riboflavin deficiency is rare in developed countries. However, a poor diet, old age, lung diseases and alcoholism can increase the risk.
The deficiency can cause a condition known as arriboflavinosis, a condition characterized by sore throat, swollen tongue, anemia and skin problems. On the other hand, the high intake of riboflavin through the diet or with supplements has no known effects.
From what sources can we obtain Riboflavin
3.Vitamin B3 or Niacin
Niacin, also known as vitamin B3, is the only vitamin B that the body can produce from another nutrient, the amino acid tryptophan. It plays an essential role in cellular function and acts as an antioxidant.
Another important function is to boost a metabolic process known as glycolysis, the extraction of energy from glucose.
3.2 Sources and intake
Niacin is found in both plants and animals. The yeast extract is rich in niacin, providing about 128 mg per 100 grams. Other sources include fish, chicken, eggs, dairy products and mushrooms.
Scientists have estimated that 60 mg of tryptophan can be used to create 1 mg of niacin. A daily intake of 30 mg is recommended for adults.
3.4 Deficiencies and side effects
Niacin deficiency is known as pellagra , and is rare in developed countries. The main symptoms include skin inflammation, diarrhea, insomnia and dementia.
Niacin of natural origin from food does not seem to have any adverse effects. However, high doses can cause nausea, vomiting, stomach irritation, insulin resistance and liver damage.
It is required for the formation of coenzyme A, necessary for the synthesis of fatty acids, amino acids and neurotransmitters.
4.2 Sources and intake
It is found in the extract of yeast, kidneys, chicken, veal, grains, broccoli and egg yolk. An intake of 5 mg per day is recommended for adults.
4.3 Deficiency and side effects
This vitamin is so widespread in food that its lack is practically unknown. However, its lack can cause irritability, sleep disturbances, restlessness and digestive problems. It does not seem to have any adverse effect at high doses.
Vitamin B6 is a group of nutrients necessary for the synthesis of pyridoxal phosphate , a coenzyme involved in more than 100 different metabolic processes.
It is involved in the formation of red blood cells, as well as in the energy and amino acid metabolism. It is also required for the release of glucose from glycogen, the molecule that the body uses to store carbohydrates.
5.2 Sources and intake
It is present in a wide variety of foods such as tuna, pork, turkey, bananas, chickpeas and potatoes. Its availability is greater in foods of animal origin. A daily intake of 80 to 100 mg in adults is suggested.
To Deficiency and side effects
The vitamin B6 deficiency is rare, but people with alcohol problems are at greatest risk. The main symptoms are anemia, rashes, convulsions, confusion and depression.
Vitamin B6 in food does not seem to have any adverse effects. However, very large doses are related to damage of the sensory nerve and skin lesions.
Symptoms of deficiency of water-soluble vitamins
6.Vitamin B7 or Biotin
It is required for carboxylases , enzymes involved in several fundamental metabolic processes. For example, biotin plays an essential role in the synthesis of fatty acids, the formation of glucose and the metabolism of amino acids.
6.2 Sources and intake
The foods rich in animal biotin include organ meats, fish, meat, egg yolk and dairy products. It can also be found in legumes, green vegetables, cauliflower, mushrooms and nuts.
The gut microbiota also produces small amounts of biotin. A daily intake of 30 micrograms (mcg) per day in adults is recommended.
6.3 Deficiency and side effects
Deficiency is relatively uncommon. The risk is higher in babies fed formula low in biotin and people taking antiepileptic drugs.
Untreated deficiency can cause neurological symptoms, mental retardation and loss of muscle coordination. It has no known adverse effects and the tolerable upper limit has not been established.
7.Vitamin B9 or Folate
Folate acts as a coenzyme and is essential for cell growth, the formation of DNA and the metabolism of amino acids. It is very important during periods of rapid cell division and growth, such as in childhood and pregnancy. In addition, it is required for the formation of red and white blood cells, so that its deficiency can cause anemia.
7.2 Sources and intake
The best sources of folate include green leafy vegetables, legumes, sunflower seeds and asparagus. The yeast extract can provide around 3,786 mcg per 100 grams.
A daily intake of 1000 mcg of folate in adults is recommended.
7.3 Deficiency and side effects
Folate deficiency is rare, but anemia is one of the classic symptoms of a lack of vitamin B9. It can also lead to congenital defects of the brain and neural tube.
No serious adverse effects of high intake of vitamin B9 have been reported, but at high doses it can mask vitamin B12 deficiency.
It is the only vitamin that contains a metallic element, cobalt.
Adequate intake helps maintain the function and development of the brain and the production of red blood cells. It is also necessary to convert proteins and fats into energy.
8.2 Sources and intake
Foods of animal origin are practically the only dietary sources of vitamin B12. These include meat, dairy products, seafood and eggs. It is recommended that adults consume 2.4 mcg per day.
8.1 Deficiency and side effects
Those who are most at risk of deficiency are those who never or rarely consume foods of animal origin, such as vegetarians and vegans. It can also develop in older people.
The deficiency can cause various health problems, such as anemia, loss of appetite, neurological problems and dementia. On the other hand, no adverse effects have been related to high intakes of vitamin B12 in healthy people.
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