Vitamin B Complex

Vitamin B Foods

Written by Esther Diong, MSc (Nutrition) on 25 April 2021
Medically Reviewed by Dr. K on 26 April 2021

Vitamin B Complex

Vitamin B complex is a series of micronutrients that is required by the body for daily cellular activities. It is composed of eight B vitamins:

Vitamin Functions Food Sources
B1 (thiamine) Thiamine helps to convert nutrients into energy Pork, sunflower seeds and wheat germ
B2 (Riboflavin) Riboflavin helps to convert food into energy and also acts as an antioxidant Organ meats, beef and mushrooms
B3 (Niacin) Niacin plays a role in cellular signalling, metabolism and DNA production and repair. Chicken, tuna and lentils
B5 (Pantothenic Acid) Pantothenic acid helps the body to obtain energy from food and is also involved in the production of hormone and cholesterol. Liver, fish, yogurt and avocado
B6 (Pyridoxine)  Pyridoxine is involved in amino acid metabolism, red blood cell production and neurotransmitters creation. Chickpeas, salmon and potatoes
B7 (Biotin)  Biotin is essential for carbohydrate and fat metabolism and regulates gene expression. Yeast, eggs, salmon, cheese and liver
B9 (Folic Acid) Folate is needed for cell growth, amino acid metabolism, the formation of red and white blood cells and proper cell division Leafy greens, liver and beans or in supplements as folic acid
B12 (Cobalamin) B12 is vital for neurological function, DNA production and red blood cell development. Meats, eggs, seafood and dairy

Although these vitamins have similar characteristics, they have unique functions and are needed in different amounts by the body. Majority of the population are able to consume adequate amounts of vitamin B complex through diet as they are found in a wide variety of food. B vitamins are water-soluble, which means excess vitamin B is not stored in the body, hence, it is necessary to have adequate amounts from one’s diet. 

How much vitamin B complex do you need?

The recommended daily amount of each B vitamins are:

Vitamin RDI for Women RDI for Men
B1 1.1 mg 1.2 mg
B2 1.1 mg 1.3 mg
B3 14 mg 16 mg
B5 5 mg (RDA not established) 5 mg (RDA not established)
B6 1.3 mg 1.3 mg
Biotin 30 mcg (RDA not established) 30 mcg (RDA not established)
Folic Acid 400 mcg 400 mcg
B12 2.4 mcg 2.4 mcg

Older adults and women who are pregnant require higher amounts of B vitamins.

Certain underlying health conditions may reduce the body’s ability to absorb vitamin B properly. For example:

  • Coeliac Disease
  • HIV
  • Crohn’s Disease
  • Alcohol Dependence
  • Kidney Conditions
  • Rheumatoid Arthritis
  • Ulcerative Colitis
  • Inflammatory Bowel Disease

Vitamin B Foods

How can you tell if you’re deficient?

The majority of the population would get sufficient B vitamins by eating a balanced diet. However, the chance of deficiency is still possible. These are some symptoms of B vitamins deficiency:

  • Skin Rashes
  • Cracks Around The Mouth
  • Scaly Skin On The Lips
  • Swollen Tongue
  • Fatigue
  • Weakness
  • Anaemia
  • Confusion
  • Irritability Or Depression
  • Nausea
  • Abdominal Cramps
  • Diarrhea
  • Constipation
  • Numbness Or Tingling In The Feet And Hands

If you’re experiencing any of these symptoms and aren’t sure why make an appointment to see your doctor. Although it’s possible that you’re experiencing a vitamin B deficiency, these symptoms also overlap with many other underlying conditions. Your doctor can make a diagnosis and advise you on any next steps.

Can being deficient increase your risk of certain conditions?

Long term untreated deficiency could increase the risks of developing:

  • Anaemia
  • Digestive Issues
  • Skin Conditions
  • Infections
  • Peripheral Neuropathy
  • Vitamin B-12 deficiency, in particular, may increase the risk of neuropsychiatric disorders.
  • Babies born to women who were deficient in folic acid during pregnancy are more likely to have birth defects.
Talk to your healthcare provider about supplements

Do talk to your healthcare provider before adding any supplements to your routine. Some supplements may interact with certain underlying conditions and medications, hence it is important to keep your healthcare provider informed.


Referenced on 24.4.2021:

  2. Stover P. J. (2010). Vitamin B12 and older adults. Current opinion in clinical nutrition and metabolic care13(1), 24–27.
  4. Bellows L, et al. (2012). Water-soluble vitamins: B-complex and vitamin C.
  5. Folic acid and pregnancy. (2014).
  6. Gao Y, et al. (2016). New perspective on impact of folic acid supplementation during pregnancy on neurodevelopment/autism in the offspring children — A systematic review. DOI:
  7. Hall-Flavin DK. (2016). Vitamin B-12 and depression: Are they related?
  8. Mayo Clinic Staff. (2016). Vitamin deficiency anemia.
  9. Mayo Clinic Staff. (2017). Peripheral neuropathy.
  10. Mayo Clinic Staff. (2017). Vitamin B-12.
  11. Oh RC, et al. (2003). Vitamin B-12 deficiency.
  12. Stover PJ. (2010). Vitamin B12 and older adults.
  13. Vitamin B complex. (n.d.).
  14. Vitamins and minerals. (2017).

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