Updated: Nov 18
Medically reviewed by Serena Benali, Registered Dietitian. Published February 14, 2023.
Vitamin C is a popular supplement due to its powerful antioxidant properties. It is an essential nutrient that helps protect the body from free radicals and other harmful toxins. Vitamin C can help boost your immune system and increase your overall health.
As a registered dietitian, I have a big food-first philosophy. What I mean by this is that I’m a big proponent of getting all the nutrients we need from food first, and then using supplements to bridge the gap to what our body needs, if needed.
As the word suggests, supplements are meant to complete or enhance a healthful diet.
When we get a certain nutrient from food we are never just getting the nutrient in isolation, we are getting it with a host of other nutrients and benefits!
The supplement industry is huge and it continues to grow at an increasing pace each year. 47% of adult Canadians take at least one supplement daily (1).
Canadians are taking supplements but are they taking the right supplements for their unique needs and body?
We’re going to talk about vitamin C; what it does in the body, how much we need daily, what happens if you consume too much, richest food sources and we’ll see if you need this supplement.
What is vitamin C?
Also known as L-ascorbic acid, vitamin C is a powerful antioxidant. Our body cannot produce it on its own so we need to obtain it exogenously (from food or supplement).
What does vitamin C do in the body?
Vitamin C is involved in many body processes including the biosynthesis of collagen and neurotransmitters, protein metabolism, immune function, and helps with the absorption of non-heme iron (iron found in plant-based foods).
Vitamin C protects the body from cancer via its antioxidant function and reduces the risk of cardiovascular disease.
Vitamin C is found throughout the body, it is in the highest levels in white blood cells (leukocytes), eyes, adrenal glands, pituitary glands and the brain (1).
How much vitamin C do you need each day?
Children 1-3 years need 15 mg/ day
Children 4-8 years need 25 mg/ day
Males 9-13 years need 45 mg/ day
Males 14-18 years need 90 mg/ day
Males 19+ years need 90 mg/ day
Females 9-13 years need 45 mg/ day
Females 14-18 years need 65 mg/ day
Females 19+ years need 75 mg/ day
Pregnancy 85 mg/ day
Lactation 120 mg/ day
Smokers need an extra 35 mg/day due to the increased oxidative stress caused by smoking (2).
Can you have too much vitamin C?
Yes, there can always be too much of a good thing.
In large doses, our gastrointestinal tract doesn’t absorb all the vitamin C. 50% is absorbed with doses above 1g/day. What happens to the rest? It’s excreted through urine.
Your body does not store vitamin C and therefore excretes the excess vitamin C through urine. In excess, this can cause diarrhea, nausea, and gastrointestinal disturbances.
Vitamin C Deficiency
Vitamin C deficiency occurs when the body is not getting enough vitamin C to meet its daily needs. This can lead to a range of health problems, including scurvy, a condition characterized by weakness, fatigue, and gum disease. In order to avoid vitamin C deficiency, it is important to ensure that your body is receiving enough of this essential nutrient to meet its daily needs.
Signs of Deficiency
Fatigue and weakness: A lack of vitamin C can lead to feelings of fatigue and weakness.
Scurvy: This condition is caused by severe vitamin C deficiency and can result in symptoms such as bleeding gums, muscle weakness, and skin rashes.
Poor wound healing: Vitamin C plays a vital role in the production of collagen, which is necessary for the healing of wounds. A deficiency can lead to slow wound healing.
Dry and rough skin: A lack of vitamin C can cause skin to become dry and rough.
Joint and muscle pain: Vitamin C deficiency can cause joint and muscle pain, which can make it difficult to move and perform daily activities.
Anemia: A lack of vitamin C can affect the absorption of iron from plant-based foods, leading to anemia.
Mood changes: Vitamin C is essential for the production of neurotransmitters, such as serotonin, which can affect mood. A deficiency can cause mood changes and depression.
Iron-deficiency anemia and vitamin C
Iron-deficiency anemia is a common type of anemia that occurs when the body doesn't have enough iron to produce hemoglobin, which is necessary for the transportation of oxygen throughout the body. One way to prevent or treat iron-deficiency anemia is to ensure adequate intake of vitamin C, which aids in the absorption of iron from plant-based foods.
Vitamin C can enhance the absorption of non-heme iron, which is the type of iron found in plant-based foods. By pairing iron-rich foods such as spinach, lentils, or tofu with foods high in vitamin C, like citrus fruits or bell peppers, you can increase the amount of iron that your body absorbs.
Where do you get vitamin C from?
You find vitamin C in many fruits and vegetables. Some of highest source of vitamin C include:
Guava 1 fruit 125 mg
Red pepper, sweet, raw, ½ cup 95 mg
Papaya ½ fruit 93 mg
Kiwifruit, 1 medium 82 mg
Orange, 1 medium 70 mg
Broccoli, cooked, ½ cup 54 mg
Strawberries, ½ cup 52 mg
Brussels sprouts, 4 sprouts cooked, 52 mg
Grapefruit, ½ fruit 44 mg
Kale ½ cup, raw chopped, 43 mg
Pineapple ½ cup 42 mg
Mango ½ fruit 38 mg
Cauliflower, raw, ½ cup 29 mg
Cabbage, cooked, ½ cup 28 mg
Do you need a vitamin C supplement?
In supplements, you'll typically find vitamin C as ascorbic acid. Other forms include sodium ascorbate and calcium ascorbate. The bioavailability of ascorbic acid is similar to that found in vitamin C rich foods.
When it comes to the world of supplements, there is big money to be made by consumers thinking that they need them or that more is always better.
If you can include vitamin C rich foods daily you’re going to get more nutritional value from those foods than you would through a supplement. If you can get your daily vitamin C intake from food go to food first, you don't need to supplement.
If you eat and enjoy the fruits and vegetables in this list above, you’ll easily be able to get your daily dose of vitamin C.
If you have a medical condition speak to your registered dietitian as you would require personalized recommendations.
3% of Canadians are deficient in vitamin C (3). If you think you’ll have some trouble meeting your daily intake take a supplement. If you choose to go with a supplement it’s important to note that Vitamin C supplements work best when taken during the day (morning) and because it’s a water-soluble vitamin it does not need to be taken with food.
Takeaways: Do you need a vitamin C supplement?
Vitamin C is a powerful antioxidant that is involved in many body functions. Your body doesn’t store it so you need to consume it every day through food.
Vitamin C is found in high levels in many fruits and vegetables. We always want to think about food first when it comes to nutrition. If you can get your daily intake through food that’s best because you’re getting many other benefits besides the vitamin C, like other micronutrients and fibre!
Supplements are costly and not always necessary if you can meet your daily intake of vitamin C don't bother buying supplements.
Extra vitamin C in supplements is not as beneficial as vitamin C from food so think of food first and put the supplements down.
Download our FREE meal plan with simple recipes (10 ingredients or less) and meet your daily vitamin C intake - supplement free!