How long should I stop taking vitamin c? What is the dosage?

22.03.23 115

Vitamin C is a mineral that is beneficial for humans, but the more it is used, the better for health. So how long should I stop taking Vitamin C? What are the dosage limits and recommended doses? Let’s answer the above questions with Solife in the following article!

1. The use of vitamin C

Vitamin C is a vitamin that the body needs to form blood vessels, cartilage, muscle, and collagen in bones and is present in many of the following metabolic processes:

  • Participate in the metabolism of protid, lipid, glucide,…
  • Participating in the synthesis of substances such as adrenocortical hormones, catecholamines,..
  • Is a reaction catalyst that converts Fe+++ to Fe++ so that iron can be absorbed in the duodenum. That’s why vitamin C deficiency also leads to iron-deficiency anemia
  • Helps increase resistance, the body’s immune system by creating interferon and reducing the body’s sensitivity to histamine.
  • Combined with vitamin A and vitamin E, it participates in the antioxidant process, neutralizing free radicals produced by metabolic reactions, thereby preserving cell membranes.


Vitamin C deficiency can lead to a number of diseases such as anemia, bleeding gums, bruising and slow wound healing. Especially in people with gastrointestinal problems and cancer, vitamin C deficiency reduces iron absorption from the digestive tract.

However, the body cannot produce vitamin C on its own, so you need to get enough vitamin C through your diet. Additionally, vitamin C is also available as capsules and chewable tablets.

Read more: What are the top 12 foods contain Vitamin C?

2. Limited Dosage of Vitamin C

According to nutritionists, the maximum limit of vitamin C that the body can accept is 2,000mg for people over 19 years old. The same applies to pregnant and lactating women.


For young children and infants, specific daily vitamin C limits are:

  • Children 1-3 years old: 400mg
  • Children 4 – 8 years old: 650mg
  • Children 9-13 years old: 1,200mg
  • Teenagers 14-18 years old: 1,800mg

There are also limited doses of vitamin C for specific exceptions. However, the exception limit dose is usually applied only with the consent of medical professionals.

3. Recommended Dosage of Vitamin C

The recommended daily dose of vitamin C for people in each specific age group is as follows:

  • Children from 1 to 3 years old: 15mg
  • Children from 4 to 8 years old: 25mg
  • Children from 9 to 13 years old: 45mg
  • Teenagers 14-18 years old: 75mg (for men) and 65mg (for women)
  • Adults over 19 years: 90mg (for men) and 75mg (for women)

There are some special cases that need vitamin C supplementation such as:

  • Smokers should add 35mg/day more than the recommended dose
  • Pregnant women should supplement with 85mg of vitamin C daily
  • Breastfeeding women should supplement with 120mg of vitamin C daily

To date, there have been no studies on the dosage of vitamin C for children under 1 year of age. Experts have given estimates:

  • Children under 6 months: 40mg
  • Children 7 – 12 months: 50mg

However, the body does not absorb all the vitamin C that is taken into the body. If the amount of vitamin C taken per day is 30-180mg, only 70-80% of that vitamin C is absorbed by the body. The absorption rate of vitamin C is only about 50% if a person takes more than 1g of vitamin C per day. Unabsorbed vitamin C is excreted in the urine.

4. How long should vitamin C be taken?

Taking vitamin C is used in many different cases and depending on the purpose of use, the recommended dosage and frequency of vitamin C for how long is recommended as follows:

  • Take vitamin C to treat the common cold: 200mg – 3grams taken daily for 3 to 5 days or longer.
  • Take vitamin C for antioxidants: 200 – 1,000 milligrams of vitamin C taken daily for 4 weeks to 1 year; 300 – 3,000 milligrams of vitamin C intravenously as a single dose or injection for 8 weeks.
  • Take vitamin C to prevent breast cancer: 500 milligrams of vitamin C taken daily.
  • Take vitamin C to prevent cancer: 120-2,000 milligrams of vitamin C taken daily for 6 to 8 years.
  • Taking vitamin C to prevent colds for people working in harsh environments: 200 milligrams of vitamin C taken daily for 14 days.
  • Take vitamin C to prevent common colds: 30-3,000 milligrams of vitamin C taken daily during winter for 2 to 8 weeks.
  • Take vitamin C to boost fertility: 750 milligrams of vitamin C taken daily for 6 months.
  • People with heart disease: 2 grams of vitamin C taken before surgery, then 1 gram daily for 5 days.
  • People with high blood pressure: 60-4,000 milligrams of vitamin C taken daily for 6-16 weeks.
  • People with kidney disease: 3 grams of vitamin C taken before detox procedures, then 2 grams in the evening and again in the morning; 100-200 milligrams of vitamin C taken daily.
  • People with for liver disease: 120-3000 milligrams of vitamin C taken daily for 1 day to 6 months.


  • People with prostate cancer: 500 milligrams of vitamin C by mouth daily for about 8 years.
  • People with anemia: 200-300 milligrams of vitamin C intravenously 3 times per week, for 3-6 months.
  • Taking vitamin C to prevent gout: 500 – 1,500 milligrams of vitamin C per day from foods or from dietary supplements.
  • Taking vitamin C with people with metabolic disorders: 100 milligrams of vitamin C taken daily.
  • Take vitamin C to treat rickets: You can inject or take vitamin C to treat rickets. For oral administration: 100 – 250 milligrams of vitamin C taken 4 times daily for one week. Then take 1-2 grams per day for 2 days, followed by 500 milligrams per day for 1 week. The treatment should be strictly supervised by medical professionals.


Hopefully the above article of Solife has helped you solve the question of how long to stop taking vitamin C. Taking vitamin C in the right way and at the right dose not only helps strengthen resistance but also helps prolong youth thanks to its high anti-aging ability. Therefore, consult your doctor for how long before using vitamin C supplements to ensure your health.

Trần Hoàng Uyên (Senior Manager Pharmaceutical company) là chuyên gia cấp cao với nhiều năm kinh nghiệm trong lĩnh vực dược phẩm. Tốt nghiệp cử nhân chuyên ngành Quản lý dược I tại Trường Đại học Y dược TP. Hồ Chí Minh và hiện đang công tác tại công ty dược phẩm. Với hơn 10 năm kinh nghiệm làm việc trong ngành dược, chị Hoàng Uyên là chuyên gia cộng tác tham vấn y khoa cho danh mục blog cũng như các nội dung liên quan trên Solife. (Tran Hoang Uyen (Senior Manager Pharmaceutical company) is a senior specialist with many years of experience in the Pharmaceutical field. She graduated Bachelor of Pharmacy Management I at the University of Medicine and Pharmacy at Ho Chi Minh City and is currently working for a pharmaceutical company. With more than 10 years of experience working in the pharmaceutical industry, Ms. Hoang Uyen is a medical consultant collaborator for content on Solife's website.)