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Vitamin C benefits, dosage, and deficiency

Known for it's immunity boosting properties, Vitamin C is a powerful nutrient. Explore it's benefits in this guide. 

ingredients 07 vitamin-C illustration
Sophie Medlin
Sophie Medlin
Head of Nutritional Research
June 30, 2022
9 min read

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!)

Article breakdown

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

Within your central nervous system and brain, vitamin C:

  • Works as a neuromodulator, meaning it helps your cells to properly use important neurological chemicals like dopamine.

  • Helps with neuronal maturation, which is the complex process of generating brain cells and creating/maintaining your neural connections.

  • Protects your brain cells and nervous system tissue from damage caused by free radicals.

  • Reduces brain inflammation.

By supporting these important elements and processes in your brain, vitamin C may lead to benefits like:

  • Improved moods: Studies have found that high vitamin C levels in your blood correlate with lower levels of depression, anger, etc.

  • Protection against neurodegenerative diseases, such as Alzheimer's disease and multiple sclerosis.

  • Improved cognitive functioning, including enhanced memory, focus and concentration.

  • Increased mental energy, because vitamin C plays a vital role in the production of oxygenated blood cells, which in turn help guard against mental fatigue.

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Benefits of vitamin C on the body 

Beyond the brain, vitamin C is good for your general health and wellness. There are the well-known immunity benefits, of course, but also so much more:

  • Reduced risk of chronic disease: Oxidative stress is one of the underlying risk factors of numerous common diseases, and vitamin C's antioxidant properties reduce oxidative stress.

  • Enhanced cardiovascular health: More than 40 years of research has demonstrated vitamin C’s significant impact on your blood pressure, and one study even found that taking a vitamin C supplement reduced your risk of heart disease by 25 percent.

Vitamin C benefits for skin

We've covered the brain and the rest of your body, 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.

So, what are 5 benefits of vitamin C?

As you can see, there are many vitamin C benefits. To summarise, here are 5 you should be aware of:

  1. Improved immune function

  2. Improved mood and cognitive function

  3. Enhanced cardiovascular health

  4. Reduced risk of chronic disease

  5. Improved skin health

Deficiency symptoms 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).

You’ve likely heard tales of scurvy, the dreaded (and deadly) disease caused by vitamin C deficiencies that was prevalent amongst 18th-century sailors and explorers. 

Scurvy still exists today, but many people who are low on vitamin C experience far more subtle signs and symptoms:

  • Poor skin health, including dry skin, skin rashes and skin bumps.

  • Easy bruising that doesn’t go away quickly, since vitamin C is required for your connective tissues and wound healing.

  • Poor hair and fingernail health, including brittle nails or changes in hair colour.

  • Low immunity, such as constantly falling ill with whatever bug is circulating in your home, office or community.

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. For example, Heights Smart Supplement conveniently provides a full day’s worth of this vital antioxidant.

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. 

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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.

How we use vitamin C in Heights' Smart Supplement 

At Heights, we've formulated the Smart Supplement with pure ascorbic acid (vitamin C) for your benefit:

  • Each dose contains 100% of your daily requirements of vitamin C for optimal brain health and cognition.

  • The ascorbic acid is pure and quality-tested.

  • Everything is manufactured in small batches so you can rest assured that your vitamin C is safe and potent.

  • It meets many common dietary and lifestyle practices: It's gluten-free, 100% plant-based, allergen-free and contains no GMOs, contaminants, fillers or colourants.


Here's a handful of relevant scientific studies on vitamin C:

  • Smart Supplement
  • Braincare Journal
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