An Introduction to Dosing With Vitamin C
The recommended
vitamin C dose can vary, depending on several factors. Pregnant and breastfeeding women need higher doses, as do people who smoke.
Vitamin C Doses and Recommended Dietary Allowances
The Institute of Medicine has developed two different dosing guidelines for vitamin C, the RDA (recommended dietary allowance) and UL (tolerable upper limit).
The RDA is the intake recommended for the average person, and the UL is the maximum that can be taken without significant side effects or toxicity. Refer to the following table for RDA and UL values for vitamin C:
|
Age
|
Vitamin C RDA
|
Vitamin C UL
|
|
1-3 years
|
15 mg per day
|
400 mg per day
|
|
4-8 years
|
25 mg per day
|
650 mg per day
|
|
9-13 years
|
45 mg per day
|
1200 mg per day
|
|
14-18 years
|
Females
|
65 mg per day
|
1800 mg per day
|
|
Males
|
75 mg per day
|
|
19 years and older
|
Females
|
75 mg per day
|
2000 mg per day
|
|
Males
|
90 mg per day
|
|
Pregnant women
|
18 years and under
|
80 mg per day
|
1800 mg per day
|
|
19 years and older
|
85 mg per day
|
2000 mg per day
|
|
Breastfeeding women
|
18 years and under
|
115 mg per day
|
1800 mg per day
|
|
19 years and older
|
120 mg per day
|
2000 mg per day
|
For smokers, an additional 35 mg of vitamin C over the usual RDA is recommended.
Many people may be able to meet their RDA for vitamin C through food, since many foods naturally contain it. Also, additional vitamin C is often added to various foods and beverages. However, vitamin C content decreases when foods and beverages are cooked or stored. Frozen orange juice (the concentrated kind that is mixed with water) usually contains more active vitamin C than ready-to-drink orange juice. With time, the vitamin C in ready-to-drink orange juice oxidizes and becomes much more difficult to absorb.
