Vitamin C benefits and dosage

While most people think of vitamin C as simply an immune-boosting nutrient, as an essential antioxidant vitamin C benefits all aspects of your health and wellness—including your brain health.

Whether you're struggling to get enough vitamin C in your diet, or you're trying to navigate the many vitamin C supplement options available, the following supplement guide will outline everything you need to know about vitamin C benefits, including:

• The vital functions that vitamin C supports in your body

• How vitamin C benefits your brain health, immune system, and other aspects of your wellness

• How to know if you're not getting enough vitamin C

• What to eat to boost your dietary intake of vitamin C

• What to look for in your vitamin C supplements (hint: not all supplements are created equal!)

Vitamin C dosage

Before we get into the benefits of vitamin C, let's look at how much you should be getting in a day (it's likely more than you think!).

Is it okay to take vitamin C everyday?

Yes! The Nutrient Reference Value (NRV—formerly RDA) for adults is 80 mg of vitamin C a day.

Is 100mg of vitamin C too much?

No—it might even be necessary!

Lifestyle plays a role. For example, smokers expose their bodies to additional oxidative stress and need 125 mg/day for men and 110 mg/day for women. There may be additional vitamin C benefits for women who are pregnant or breastfeeding if they wish to take extra too.

The tolerable upper limit for vitamin C is approximately 2,000 mg a day, and you may experience gastrointestinal discomfort like bloating, gas or loose stools if you exceed this limit. 

However, unlike vitamin A and other fat-soluble vitamins, vitamin C is water-soluble and your body will simply excrete anything it doesn’t use via your urine.

Vitamin C benefits

Because you need vitamin C for the proper functioning of your body’s systems at a cellular level, vitamin C benefits play out in numerous aspects of your daily life.

What is vitamin C good for?

Vitamin C has a crucial, foundational role in several aspects of your bodily functions:

• It helps you to metabolise nutrients such as protein and collagen, and also improves the absorption of iron and other vitamins and minerals.

• It has well-known antioxidant properties, and may even regenerate the antioxidant properties of other nutrients (such as vitamin E).

• It keeps your body healthy on a cellular level, protecting molecules and cells from damage.

• It significantly improves immune function, hence its popularity during cold and flu season.

Benefits of vitamin C for the brain 

When you eat vitamin C-rich foods, or take a vitamin C supplement, the antioxidant accumulates in your central nervous system, and especially within your brain’s neurons. 

Vitamin C benefits for skin

We've covered the brain, but what does vitamin C do for your face?

You'll be glad to know it works its magic here too. Vitamin C improves skin strength, and may even have anti-wrinkle and anti-ageing benefits in your skin.

Low levels of Vitamin C

Vitamin C deficiencies are shockingly common in Europe and North America. Depending on factors like your diet, age and even your socioeconomic status, as many as 1 in 5 men and 1 in 9 women don't get enough vitamin C (L-ascorbic acid).

Vitamin C food sources

Unlike many animals and vertebrae, we humans can't synthesise (i.e. make our own) vitamin C. That's why nutritionists and dietitians refer to it an "essential vitamin." Thankfully, this water-soluble nutrient is found in numerous foods.

While vitamin C is found in small amounts in some animal products, such as fish roe and liver, you need to eat a diet that's high in plant-based foods in order to get enough vitamin C.

Some of the best vitamin C-rich foods include:

• Citrus fruits, such as oranges, grapefruit and kiwis

• Strawberries

• Broccoli

• Tomatoes

• Bananas

• Apples

• Spinach

Vitamin C supplements

If you aren’t getting enough vitamin C, or you’re experiencing mental fog, mood changes and other symptoms of low vitamin C, you may benefit from taking a vitamin C supplement.

There are many different forms of vitamin C available in supplements, including synthetic L-ascorbic acid and natural L-ascorbic acid. Research has found no evidence that one version of vitamin C is better or worse than another, and all have high bioavailability (your body’s ability to absorb and use vitamin C. 

What are vitamin C supplements for?

Vitamin C supplements are valuable when your diet is lacking the right amount of vitamin C, or when your body is undergoing extra stress and needs additional vitamin C to support your brain health, immune health, etc. 

When taking regularly, vitamin C supplements ensure that the body’s immune system can function healthily, may lower susceptibility to infections, and may reduce severity of symptoms when you’re sick. A regular vitamin C supplementation routine may also contribute to lowering your blood pressure and reducing risks of developing cardiovascular disease.

Do vitamin C supplements work?

Research suggests that supplementing your vitamin C carries the same benefits as consuming vitamin C through your food. For instance, taking vitamin C supplements has been shown to reduce the severity of the common cold and improve overall cognitive function.

What other vitamins and minerals should I take with vitamin C?

Your body can readily absorb vitamin C on its own, so you don’t need to take other vitamins or minerals to enhance your absorption of vitamin C. While limited animal studies have suggested that taking flavonoids (the compounds found in many fruits and vegetables) may enhance vitamin C’s bioavailability, studies on people haven’t shown any improvement.

However, taking vitamin C with iron is a perfect match because vitamin C may improve your absorption of iron. 

Who should take a vitamin C supplement?

Everyone may benefit from taking vitamin C supplements, especially those who are at a higher risk of having low levels of vitamin C. High-risk groups include:

• People who drink high amounts of alcohol

• Those who smoke

• Individuals with eating disorders

• People who follow extremely restrictive diets that eliminate entire food groups, especially if those restrictions involve avoiding fruits and vegetables

How long does a vitamin C supplement take to start working?

Vitamin C is a water-soluble vitamin. Thus, it’s absorbed very quickly (often within three to six hours of taking the supplement).

Is taking a Vitamin C supplement safe?

Yes, taking a vitamin C supplement is safe, and there’s no research indicating otherwise.

Unlike fat-soluble vitamins, excess vitamin C is not stored in your body and won’t build up to dangerous levels. Any extra vitamin C that you take, and that your body doesn’t use right away, is excreted in your urine.