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Vitamin B-complex

Used for: Vitamin B-complex deficiency
Chinese name:

What is Vitamin B-complex for?

Vitamin B-complex is an umbrella term for the eight essential B vitamins needed in our bodies. The B-complex includes:

  • Vitamin B1 (Thiamin): essential in converting nutrients (carbohydrates) into energy, and in the synthesis of neurotransmitters, fatty acids and hormones
  • Vitamin B2 (Riboflavin): acts as an antioxidant, converts nutrients into energy, and helps in converting Vitamin B3 and B6 to be used by the body
  • Vitamin B3 (Niacin): converts nutrients into energy, involves in cellular signalling, metabolism, DNA production and repair
  • Vitamin B5 (Pantothenic acid): converts nutrients into energy, involves in coenzyme, hormone and cholesterol production
  • Vitamin B6 (Pyridoxine): facilitates over 100 enzyme reactions, involves in amino acid metabolism, red blood cell production, and brain development
  • Vitamin B7 (Biotin): essential for carbohydrate and fat metabolism, regulates gene expression and cellular communication
  • Vitamin B9 (Folic acid): necessary for cell growth, proper cell division, formation of red and white blood cells, and the metabolism of vitamins and amino acids
  • Vitamin B12 (Cobalamin): crucial for brain and neurological function, fat and protein metabolism, DNA synthesis, and formation of red blood cells

These vitamins have different functions individually, as well as working together in the body to sustain bodily functions, including but not limited to maintaining energy levels, brain and nerve functions, cell metabolism, growth of skin/nails/hair, and overall health.


Most people can obtain enough B vitamins by eating a balanced diet, however, in some individuals, it is still possible to be deficient. Signs and symptoms of vitamin B deficiency include skin rashes, scaly skin, swollen tongue, fatigue, weakness, anaemia, confusion, abdominal cramps, diarrhoea or constipation, numbness or tingling in the feet and hands.

How to use it?

Vitamin B-complex is available in many formulations, such as tablets, capsules or oral solutions. For specific dosages, please refer to specific product labels.


Healthy children and adults do not need supplements as they can obtain enough from a normal diet. However, people with Vitamin B-complex deficiency may take Vitamin B-complex supplements.

For women, the recommended daily intake is:

  • B1: 1.1 mg
  • B2: 1.1 mg
  • B3: 14 mg
  • B5: 5 mg (RDA not established)
  • B6: 1.3 mg
  • Biotin (B7): 30 mcg (RDA not established)
  • Folic acid (B9): 400 mcg
  • B12: 2.4 mcg

For men, the recommended daily intake is:

  • B1: 1.2 mg
  • B2: 1.3 mg
  • B3: 16 mg
  • B5: 5 mg (RDA not established)
  • B6: 1.3 mg
  • Biotin (B7): 30 mcg (RDA not established)
  • Folic acid (B9): 400 mcg
  • B12: 2.4 mcg

What are the side effects of Vitamin B-complex?

Vitamin B-complex is water-soluble and is unlikely to cause serious side effects. However, taking excessive supplements may cause bright yellow urine, vomiting, skin flushing, light sensitivity, high blood sugar levels or even liver damage.

Who should not take Vitamin B-complex?

  • Patients who are allergic to any component of the formulation

Pharmacist Tips:

  • Although you should obtain enough vitamin B from your diet, your body may require supplementation if you are over 50-year-old, pregnant, or have a vegetarian/vegan diet.
  • It is always best to consult your doctor or pharmacist before starting any supplement, especially if you already take medication, have health concerns, or are pregnant.

Common dosing schedule:

  • Please refer to specific product instructions.

Some common medications Vitamin B-complex may interact with:

Please notify your doctor or pharmacist if you are taking the above medication, dosage adjustments might be needed.


What are the other sources of Vitamin B-complex?

Most people should obtain adequate amounts of Vitamin B-complex from a healthy diet. A wide variety of food sources contain B Vitamins, such as milk and dairy products, meat, fish, shellfish, vegetables, whole grains and cereals, nuts and seeds, fruits, soy products and beans.

Where to buy Vitamin B-complex in Hong Kong?

In Hong Kong, Vitamin B-complex is an over-the-counter medicine and can be purchased without a prescription from any retail outlet in Hong Kong. This includes grocery stores, convenience stores, medicine shops, and pharmacies. It can also be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.


For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at https://www.drugoffice.gov.hk

Need more information?

For detailed information about the use of Vitamin B-complex in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.

Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.

Brands in Hong Kong
Doctor’s Choice
Available dosage
  • (Tablets)
Drug class
Sub class
Vitamins (Water Soluble)
Other drugs in same class
Vitamin B1/Thiamine
Used for: Thiamoine deficiency
Chinese name:
Vitamin B12
Used for: Peripheral neuropathy, Vitamin B12 deficiency
Chinese name:
Vitamin C (Ascorbic Acid)
Used for: Prevention and treatment of scurvy, Prevention of common cold, Vitamin C deficiency
Vitamin B5 (Supplement)
Used for: Vitamin B5 deficiency
Chinese name:
Vitamin B7 (Supplement)
Used for: Dietary supplementation
Chinese name: