Research Watch
Vitamins and minerals

B vitamins: Sources, benefits, and functions

Medically reviewed byLiza Nagarkoti, B.Sc. Nursing, M.A. Food & Nutrition, Health Officer & Clinical Researcher
Published September 9, 2023Updated February 28, 2026

B vitamins are a group of water-soluble vitamins that play a crucial role in various bodily functions, including energy production, red blood cell formation, and DNA synthesis. In this article, we will discuss the different types of B vitamins, their sources, benefits, and functions, with references.

Types and Sources of B Vitamins

There are eight types of B vitamins, each with its own specific function. Here are the different types of B vitamins and their sources:

Thiamine (B1): Found in whole grains, pork, and legumes.

Riboflavin (B2): Found in milk, eggs, and green vegetables.

Niacin (B3): Found in meat, poultry, fish, and whole grains.

Pantothenic Acid (B5): Found in meat, poultry, whole grains, and vegetables.

Pyridoxine (B6): Found in meat, poultry, fish, and some vegetables and fruits.

Biotin (B7): Found in egg yolks, liver, and some vegetables.

Folate (B9): Found in green vegetables, legumes, and fortified grains.

Cobalamin (B12): Found in animal products such as meat, fish, and dairy.

Benefits and Functions of B Vitamins

B vitamins play a crucial role in various bodily functions, including:

Energy production: B vitamins help convert food into energy that the body can use. Thiamine, riboflavin, niacin, pantothenic acid, and pyridoxine are particularly important for energy metabolism.

Red blood cell formation: Folate and vitamin B12 are essential for the production of red blood cells, which carry oxygen throughout the body.

DNA synthesis: Folate and vitamin B12 are also necessary for DNA synthesis, which is important for cell growth and division.

Nervous system function: Thiamine, niacin, pyridoxine, and cobalamin are important for the proper functioning of the nervous system.

Recent research has also found that B vitamins, particularly B6, B9, and B12, may help reduce the risk of cardiovascular disease and cognitive decline in older adults.

Deficiency Symptoms of B Vitamins

Deficiency of B vitamins can lead to various health problems. Here are some symptoms of B vitamin deficiencies:

Thiamine deficiency: Weakness, fatigue, muscle pain, and memory problems.

Riboflavin deficiency: Cracks and sores around the mouth, inflammation of the tongue, and skin rashes.

Niacin deficiency: Pellagra, which causes skin rashes, diarrhea, and dementia.

Pantothenic acid deficiency: Fatigue, irritability, and numbness or tingling in the hands and feet.

Pyridoxine deficiency: Anemia, depression, confusion, and skin rashes.

Biotin deficiency: Hair loss, skin rashes, and brittle nails.

Folate deficiency: Anemia, fatigue, and birth defects in pregnant women.

Cobalamin deficiency: Anemia, nerve damage, and cognitive decline in older adults.

Conclusion

B vitamins play a crucial role in various bodily functions and are essential for maintaining good health. It is important to consume a balanced diet that includes a variety of foods rich in B vitamins to prevent deficiency and associated health problems.

References (10)
  1. National Institutes of Health. Vitamin B6. https://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/. Accessed May 9, 2023.
  2. National Institutes of Health. Vitamin B12. https://ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/. Accessed May 9, 2023.
  3. National Institutes of Health. Thiamin. https://ods.od.nih.gov/factsheets/Thiamin-HealthProfessional/. Accessed May 9, 2023.
  4. National Institutes of Health. Riboflavin. https://ods.od.nih.gov/factsheets/Riboflavin-HealthProfessional/. Accessed May 9, 2023.
  5. National Institutes of Health. Niacin. https://ods.od.nih.gov/factsheets/Niacin-HealthProfessional/. Accessed May 9, 2023.
  6. National Institutes of Health. Pantothenic Acid. https://ods.od.nih.gov/factsheets/PantothenicAcid-HealthProfessional/. Accessed May 9, 2023.
  7. National Institutes of Health. Vitamin B6. https://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/. Accessed May 9, 2023.
  8. National Institutes of Health. Biotin. https://ods.od.nih.gov/factsheets/Biotin-HealthProfessional/. Accessed May 9, 2023.
  9. National Institutes of Health. Folate. https://ods.od.nih.gov/factsheets/Folate-HealthProfessional/. Accessed May 9, 2023.
  10. MedlinePlus. Vitamin B Complex. https://medlineplus.gov/druginfo/natural/313.html. Accessed May 9, 2023.
About the Reviewer
Medically Reviewed By
Liza Nagarkoti
Liza Nagarkoti, B.Sc. Nursing, M.A. Food & Nutrition
Health Officer & Clinical Researcher

Specializing in Emergency Care, Maternal Health, and Therapeutic Nutrition

See full bio & reviewed articles