Vitamin C is a water-soluble nutrient with many vital functions in your body.
It helps strengthen your immune system, aids collagen production and wound healing, and acts as an antioxidant to protect your cells from free radical damage.
Vitamin C is also known as L-ascorbic acid or simply ascorbic acid.
Unlike other animals, humans cannot synthesize vitamin C on their own. Therefore, you must get enough of it from foods or supplements to maintain good health.
This article explains the recommended dosage of vitamin C for optimal health.
What’s the recommended daily intake of vitamin C?
The Institute of Medicine (IOM) has developed a set of reference values for specific nutrient intake levels, including vitamin C.
One set of guidelines is the recommended dietary allowance, which considers the average daily nutrient intake from foods and supplements.
The recommended dietary allowance for specific gender and age groups should meet the nutrient needs of 97–98% of healthy individuals.
Here is the recommended dietary allowance for vitamin C:
- Kids (1–3 years): 15 mg
- Kids (4–8 years): 25 mg
- Adolescents (9–13 years): 45 mg
- Teens (14–18 years): 65–75 mg
- Adult women (aged 19 and older): 75 mg
- Adult men (aged 19 and older): 90 mg
- Pregnant women (aged 19 and older): 85 mg
- Breastfeeding women (aged 19 and older): 120 mg
In addition to the recommended dietary allowance recommendations for vitamin C, the Food and Drug Administration (FDA) has issued a recommended daily value.
The daily value was developed for food and supplement labels. It helps you determine the percentage of nutrients in a single serving of food compared with the daily requirements.
The recommended daily value for vitamin C for adults and children aged four and above is 60 mg, regardless of gender. However, in January 2020, this will increase to 90 mg.
Summary: The recommended dietary allowance for Vitamin C ranges from 15–75 mg for children, 75 mg for adult women, 90 mg for adult men, and 85–120 mg for women who are pregnant or breastfeeding.
Vitamin C benefits
Vitamin C is essential for overall health and wellness; the nutrient may particularly benefit certain conditions.
The vitamin is beneficial for immune health and supports your immune system’s cellular function.
Vitamin C supplements may help prevent infection, while a vitamin deficiency makes you more susceptible to infection.
For example, some research suggests that although regular vitamin C intake likely won’t prevent you from catching a cold, it may reduce the duration or severity of cold symptoms.
A review of 31 studies found that consuming 1–2 grams of vitamin C daily reduced cold duration by 18% in children and 8% in adults.
In addition, it’s known that vitamin C increases iron absorption. Thus, individuals with iron deficiency might benefit from increasing their vitamin C intake.
Summary: Regularly getting 1–2 grams of vitamin C daily may reduce the duration of common cold symptoms and boost your immune system. It might also help prevent iron deficiency anemia.
Best food sources of vitamin C
Typically, the best sources of vitamin C are fruits and vegetables.
It’s important to note that vitamin C in food is easily destroyed by heat, but since many good nutrient sources are fruits and vegetables, eating some of those raw foods is an easy way to reach the recommended intake.
For example, a 1/2-cup (75-gram) serving of raw red pepper provides 158% of the recommended dietary allowance set by the IOM.
The table below displays the vitamin C content and contribution to the recommended daily value for some of the best food sources of the nutrient.
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This table is based on the current 60-mg recommendation, but since any food providing 20% or more of the daily value for vitamin C is considered a high source, many of these foods will still be great sources after the daily value recommendation was changed to 90 mg in January 2020.
Great food sources of vitamin C include:
- Red pepper, 1/2 cup (75 grams): 95 mg (158% of the daily value)
- Orange juice, 3/4 cup (177 ml): 93 mg (155% of the daily value)
- Kiwifruit, 1/2 cup (90 grams): 64 mg (107% of the daily value)
- Green pepper, 1/2 cup (75 grams): 60 mg (100% of the daily value)
- Broccoli, cooked, 1/2 cup (78 grams): 51 mg (85% of the daily value)
- Strawberries, fresh, 1/2 cup (72 grams): 49 mg (82% of the daily value)
- Brussels sprouts, cooked, 1/2 cup (81 grams): 48 mg (80% of the daily value)
Summary: The best food sources of vitamin C are fruits and vegetables. The nutrient is easily destroyed by heat, so consuming these foods raw might maximize your nutrient intake.
Best vitamin C supplements
When looking for a vitamin C supplement, you might see the nutrient in a couple of different forms:
- ascorbic acid
- mineral ascorbates, such as sodium ascorbate and calcium ascorbate
- ascorbic acid with bioflavonoids
Choosing a supplement with ascorbic acid is usually a good choice, as it has a high level of bioavailability, meaning your body absorbs it quickly.
Additionally, given that most multivitamins contain ascorbic acid, choosing a multivitamin will boost your vitamin C intake and other nutrients.
To ensure you’re receiving adequate amounts of vitamin C from the supplement you choose, look for a supplement that provides between 45–120 mg of this vitamin, depending on your age and sex.
Summary: Vitamin C supplements come in various forms. Choose a supplement with ascorbic acid to make it easier for your body to absorb the nutrient.
Can you take too much vitamin C?
Although vitamin C has a low toxicity risk in healthy individuals, consuming too much of it can cause adverse gastrointestinal side effects, including cramps, nausea, and diarrhea.
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Additionally, since a high vitamin C intake increases the body’s absorption of non-heme iron, consuming too much vitamin C could cause problems for people with hemochromatosis, a condition in which the body retains too much iron.
Because of the potential side effects of excessive vitamin C, the IOM has established the following tolerable upper intake levels for the vitamin:
- Kids (1–3 years): 400 mg
- Kids (4–8 years): 650 mg
- Adolescents (9–13 years): 1,200 mg
- Teens (14–18 years): 1,800 mg
- Adults (aged 19 and older): 2,000 mg
Summary: To avoid gastrointestinal side effects, keep your vitamin C intake within the tolerable upper intake levels established by the IOM. Individuals with hemochromatosis should be particularly cautious when taking vitamin C supplements.
Vitamin C is a water-soluble and essential antioxidant that plays many roles in your body and supports wound healing, collagen formation, and immunity.
The recommended dietary allowance for vitamin C is 45–120 mg, depending on age and sex.
Vitamin C supplements should meet the recommended dietary allowance and stay well below the established tolerable upper intake levels — 400 for young children, 1,200 mg for kids aged 9–13, 1,800 mg for teens, and 2,000 mg for adults.
Consuming various vitamin-C-rich fruits and vegetables can also go a long way in supporting optimal health and wellness.