Nepedia
Back to Discover
Advanced Reader
🧬

B vitamins

life science Maturity 11-13 Next article →

B vitamins are a chemically diverse class of water-soluble compounds. These vitamins are essential for life because they support cell metabolism and the synthesis of red blood cells. Metabolism is the set of chemical processes that turn nutrients into energy. Because they dissolve in water, any excess B vitamins are generally excreted by the body.

Vitamin B precursors
Vitamin B precursors

Each B vitamin performs a specific job within the body. Some act as coenzymes, which are molecules that help enzymes trigger chemical reactions. Others act as precursors. A precursor is a starting material used to build a more complex molecule. For example, vitamin B2 is a precursor for coenzymes called FAD and FMN. These are necessary for flavoprotein enzyme reactions and the activation of other vitamins.

There are eight primary B vitamins, often taken together as a vitamin B complex. Vitamin B1, known as thiamine, acts as a coenzyme in the catabolism of sugars and amino acids. It helps release energy from carbohydrates and supports nerve function. Vitamin B2, or riboflavin, is involved in the electron transport chain and the citric acid cycle. Vitamin B3, or niacin, is a precursor to coenzymes called NAD and NADP. These coenzymes are vital for transferring energy during the metabolism of glucose, fat, and alcohol.

Niacin structure
Niacin structure

Other vitamins in the group serve specialized biological roles. Vitamin B5, or pantothenic acid, is a precursor to coenzyme A. This molecule is needed to metabolize many different substances, including fatty acids and carbohydrates. Vitamin B6, also called pyridoxine, serves as a cofactor in many enzymatic reactions, especially in amino acid metabolism. Vitamin B7, or biotin, is a coenzyme for carboxylase enzymes. These enzymes are required for the synthesis of fatty acids and a process called gluconeogenesis.

Biotin structure JA
Biotin structure JA

Two vitamins are particularly critical for growth and cell division. Vitamin B9, known as folate, is a precursor needed to make, repair, and methylate DNA. It is especially important during infancy and pregnancy when cells divide rapidly. Folate also aids in erythropoiesis, which is the production of red blood cells.

Folic acid
Folic acid

Vitamin B12, or cobalamin, is involved in the metabolism of all animal cells. It is essential for DNA synthesis, fatty acid metabolism, and the production of blood cells in the bone marrow.

Cobalamin skeletal
Cobalamin skeletal

Deficiencies in these vitamins can lead to serious health issues. A lack of thiamine can cause beriberi, a disease that affects the nervous system and the heart. A deficiency in niacin can cause pellagra, which may lead to dermatitis, diarrhea, and dementia. Folate deficiency in pregnant women is linked to neural tube defects, such as spina bifida. Because B12 is mostly found in animal products, those on a vegan diet may face deficiency risks. This is because B12 is not abundantly available from plant products.

Thiamin
Thiamin

We find B vitamins in many different types of food. They are abundant in meat, eggs, and dairy products. You can also find them in leafy green vegetables, beans, and whole grains. Because processing carbohydrates like white flour removes these vitamins, many countries use enrichment. This means thiamine, riboflavin, niacin, and folic acid are added back to the flour. Some people, such as athletes or the elderly, may use dietary supplements to ensure they meet their energy and absorption needs.

531 words

Where will your curiosity go next?

Keep exploring at your chosen reading level.

🖼️ Images & Media (9)
File:Thiamin.svg
Thiamin.svg
File:Riboflavin.svg
Riboflavin.svg
File:Niacin structure.svg
Niacin structure.svg
File:(R)-Pantothenic acid Formula V.1.svg
(R)-Pantothenic acid Formula V.1.svg
File:Pyridoxal-phosphate.svg
Pyridoxal-phosphate.svg
File:Biotin structure JA.png
Biotin structure JA.png
File:Folic acid.svg
Folic acid.svg
File:Cobalamin skeletal.svg
Cobalamin skeletal.svg
File:Vitamin B precursors.png
Vitamin B precursors.png
More to explore

✨ What else?

Related topics you might enjoy

🔬 Go deeper

More advanced topics to explore

🪜 Step back

Simpler topics to build understanding

What is Nepedia?

A free, ad-free encyclopedia for children. Every article is written at five reading levels, so the same page works for a five-year-old and a fifteen-year-old — use the level switcher above to see this one change. No account needed to read.