Recommended Dose Of Vitamin C And Notes When Taking It

21.02.23 216

Vitamin C is an essential vitamin and plays an important role in the body, because it contributes to the formation of blood vessels, cartilage, muscle and collagen in bones. However, not every vitamin C intake is good, but we need to pay special attention to the recommended dose of vitamin C for the body to be effective when supplementing. In this article, Solife informs you about the dosage and notes when taking vitamin C.

1. The use of vitamin C for the body

The use of vitamin C for the body is really great and extremely valuable. It contributes to the proper functioning of bones, muscles, blood vessels and connective tissues. Therefore, you need to supplement with adequate amounts of vitamin C for your body and achieve the following benefits:

Strengthening resistance: Supplementing with vitamin C will help the body to have a good resistance, can fight cold diseases, help time to heal faster.

Increases iron absorption: Vitamin C helps the body to increase iron absorption in both children and adults.

Reduce the risk of vision loss in old age: People at risk of macular degeneration should take a combination of vitamins E, C, zinc, beta-carotene to prevent vision loss in old age.


Preventing arrhythmias: To prevent this type of heart rhythm before and after surgery, doctors often recommend that patients take vitamin C before and after a few days.

Prevent respiratory infections: For people who exercise at high intensity and heavy like athletes, it is recommended to take vitamin C to prevent respiratory infections.

Sun protection for the skin: The combination of taking and applying vitamins C and E will help the skin be able to withstand the harmful effects of direct sunlight, helping the skin to prevent sunburn and tanning.

Anti-aging: On the market, there are many cosmetic brands that produce skin creams containing Vitamins E, C that are used to slow down the aging process of the skin.

2. Effective dosage of vitamin C

2.1 Recommended dose of vitamin C

Different subjects will correspond to the recommended doses of vitamin C. Here is a table of dosages recommended by experts:

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


Besides, there are some cases where there will be different recommended dosages corresponding to health conditions such as:

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

However, the amount of vitamin C when ingested into the body will not be completely absorbed. The body will absorb 70-80% of vitamin C when supplementing with 30-180 mg/day. The remaining amount of vitamin C will be excreted in the urine.

2.2 Dosage limits when taking vitamin C

According to medical experts, for people 19 years and older, the dose limit is 2,000 mg. The same applies to pregnant and lactating women. But for children and infants, there will be limits as follows:

  • 400 mg for infants 1 year to 3 years old.
  • 650 mg for children 4 to 8 years old
  • 1,200 mg for children 9 to 13 years old
  • 1,800 mg for adolescents aged 14 to 18 years

In addition, there will be exceptions, the limit may be increased or decreased depending on the health status of the user. These cases will usually be consulted and approved by a new doctor.

3. Is taking an overdose of vitamin C harmful?

Although vitamin C is an essential substance, if used in excess (beyond the limit dose) for a long time will cause you to face many side effects that are dangerous to your body’s health. The following are the harmful effects of taking an overdose of vitamin C:

Having problems with the digestive system

When supplementing with more than you can receive, the most obvious sign is that you will experience digestive system problems such as stomach cramps, nausea and diarrhea, dizziness, headache, heartburn Because when taken in excess will make the digestive system disorder leading to improper absorption of vitamin C. This is also the reason that we should not take vitamin C at night.


Kidney stones

Kidney stones Vitamin C added to the body will metabolize and produce oxalate compounds, which are then excreted in the urine. However, taking an overdose of vitamins will cause the amount of oxalate in the body to increase, which can bind with minerals and form crystals that remain in the body and cause kidney stones.

Causing iron retention

One of the uses of Vitamin C is to enhance the body’s ability to absorb iron. However, if you add too much vitamin C, it will lead to an excess of iron and cause many harms to the body.

People who already have high iron levels should be aware and should not take an overdose of vitamin C, it can cause iron poisoning when absorbed too much. In addition, excess iron can damage organs such as the heart, liver, pancreas, thyroid, and central nervous system of the body.

Heart-related disease

Some studies have concluded that taking an overdose of vitamin C has the potential to increase the risk of heart disease for the body, especially those with underlying conditions.

4. Notes when taking vitamin C you need to know

In addition to the recommended dose of vitamin C, you should know the following notes to help your body achieve good results during vitamin C supplementation:

  • Drink plenty of water when taking vitamin C supplements: The vitamin is a water-soluble substance. Therefore, it is necessary to drink a lot of water when supplementing with vitamin C to help the absorption and elimination of vitamin C take place smoothly and effectively.
  • Supplement as directed: Because vitamin C supplements come in many forms and types, you need to be especially careful to use them exactly as directed on the label, label or doctor’s words.
  • Take the right dose of vitamin C allowed and recommended: Not every vitamin C intake is good, you should take the correct dose recommended to avoid facing harmful side effects to the body.
  • Drink at the right time: Note that vitamin C should not be taken on an empty stomach and late at night.
  • Avoid long-term vitamin C overdose: Avoid this without your doctor’s approval. If you have accidentally used an overdose for a long time, do not stop taking it suddenly, but reduce the dose gradually.

In addition, if your body condition becomes abnormal after using vitamin C, you need to immediately go to the nearest medical center for timely examination, advice and treatment.


Must recognize the extremely good effects that vitamin C brings to our body. However, should not be used indiscriminately, but should be used in accordance with the recommended oral dose of vitamin C corresponding to each subject to avoid experiencing side effects. Besides, it is also necessary to know the notes when taking vitamin C to help the body achieve the best absorption efficiency. Finally, if you have any questions or concerns for Solife, please contact us immediately!


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.)