Medicines & Supplements A to Z > Vitamin C

Vitamin C

Last updated on June 27, 2019.

Overview   |   Dosage   |   Side Effects   |   Where To Buy  

GENERIC NAMES: Ascorbic acid, Vitamin C


COMMON BRANDS IN HONG KONG: Ceelin, Chewette C, Vitamin C Jamieson, Vitamin C Sunward, Redoxan (Vitamin C, Zinc)

What is Vitamin C for?

Vitamin C is an antioxidant that prevents damage caused by free radicals. It is also responsible for the growth, development and repair of all body tissues and involved in different body functions like the production of collagen, which helps with wounds healing and maintain the functions of cartilage, bones and teeth, as well as absorption of iron and maintenance of immune system. Since your body cannot produce Vitamin C, you must obtain it from a diet that is rich in Vitamin C such as vegetables and citrus fruits. You may also get Vitamin C dietary supplements. In clinical practice, Vitamin C is most often used to treat the common cold and taking together with oral iron supplements to enhance their absorption into the body. 

How to use it?

Vitamin C can be taken orally. The usual adult dose is 500 mg 2 times per day. If you are using Vitamin C to help with iron absorption, you may take 250 mg with each dose of iron.

Does Vitamin C have side effects?

Vitamin C is a very safe water soluble vitamin. Rarely however, flushing, nausea and vomiting, diarrhoea, or headache may occur. 

Where to buy Vitamin C in Hong Kong?

In Hong Kong, Vitamin C is an over-the-counter medicine which 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

For detailed information about the use of Vitamin C 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.