top of page
  • Dr. Mark Freund

All About Vitamin C

A healthy immune system is what makes the difference between getting sick, say, once a year and coming down with colds and other illnesses on a regular basis. Although many people fall into the trap of believing that an endless supply of vitamins and supplements is the gateway to a pristine immune system, just about any dietitian will tell you that you should first try boosting your immunity with solid, wholesome foods and healthy teas. Most people know a thing or two about vitamin C, like that it's in oranges or that without it, you can develop scurvy. But, what are the real benefits of Vitamin C, and how can you get them in your nutrition?

What is Vitamin C?

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.

Why Do We Need Vitamin C?

Vitamin C is a vital nutrient for health. It helps form and maintains bones, skin, and blood vessels. It is also an antioxidant. Vitamin C occurs naturally in some foods, especially fruits and vegetables.

The body needs vitamin C for various functions. Here are some of them:

  • It helps the body produce collagen, L-carnitine, and some neurotransmitters.

  • As an antioxidant, it helps remove unwanted substances known as reactive oxidative species (ROS) from the body.

  • It helps the body absorb iron.

  • It boosts the immune system.

  • It enhances wound healing.

ROS are substances such as free radicals that result from natural bodily processes, exposure to pollution, and other factors. They can lead to oxidative stress, which can, in turn, cause cell damage. Vitamin C's antioxidant activity may help reduce inflammation and lower the risk of developing various conditions, including some cancers. The body needs vitamin C to produce collagen. This is the main component of connective tissue and makes up 1–2% of muscle tissue.

Benefits of Vitamin C

Vitamin C is essential for overall health and wellness, and the nutrient may particularly benefit certain conditions. The vitamin is especially helpful for immune health, as it supports your immune system's cellular function. Here are the primary benefits of Vitamin C.

Promotes Natural Healing

Vitamin C helps the body produce collagen and is present in skin, muscle, and other tissues. People with a low intake of vitamin C may experience slower wound healing, as their bodies will be less able to produce collagen. During times of recovery, healthcare professionals may recommend supplements for people with low vitamin C levels.

Boosts Immunity

One of the main reasons people take vitamin C supplements is to boost their immunity, as vitamin C is involved in many parts of the immune system. First, vitamin C helps encourage the production of white blood cells known as lymphocytes and phagocytes, which help protect the body against infection.

immune booster and vitamin c rich foods

Also, vitamin C helps these white blood cells function more effectively while protecting them from damage by potentially harmful molecules, such as free radicals. This vitamin is an essential part of the skin's defense system. It's actively transported to the skin, where it can act as an antioxidant and help strengthen the skin's barriers.

Studies have also shown that taking vitamin C may shorten wound healing time. What's more, low vitamin C levels have been linked to poor health outcomes. For example, people who have pneumonia tend to have lower vitamin C levels, and vitamin C supplements have been shown to shorten the recovery time.

Promotes Healthy Aging

Antioxidants protect you from free radicals, which are unstable molecules that are linked to disease and aging. Vitamin C is one of the most potent antioxidants and can help increase the levels of antioxidants in your blood.

This, in turn, helps prevent many chronic diseases. Antioxidants have been shown to fight heart disease, cancer, Alzheimer's and help delay the physical effects of aging. In short, they're super important for your health, and getting as many of them in your diet or through high-quality supplementation is a really good idea.

Helps Prevents Cardiovascular Diseases

Heart disease is the leading cause of death worldwide. Many factors increase the risk of heart disease, including high blood pressure, high triglyceride or LDL (bad) cholesterol levels, and low levels of HDL (good) cholesterol.

Vitamin C may help reduce these risk factors, which may reduce heart disease risk. For example, an analysis of 9 studies with a combined 293,172 participants found that after ten years, people who took at least 700 mg of vitamin C daily had a 25% lower risk of heart disease than those who did not take a vitamin C supplement. Interestingly, another analysis of 15 studies found that consuming vitamin C from foods — not supplements — was linked to a lower risk of heart disease.

However, scientists were unsure whether people who consumed vitamin C-rich foods also followed a healthier lifestyle than people who took a supplement. Thus, it remains unclear whether the differences were due to vitamin C or other aspects of their diet. In short, it seems that taking or consuming at least 500 mg of vitamin C daily may reduce the risk of heart disease. However, if you already consume a vitamin-C-rich diet, then supplements may not provide additional heart health benefits.

Approximately one-third of American adults have high blood pressure. High blood pressure puts you at risk of heart disease, the leading cause of death globally.Studies have shown that vitamin C may help lower blood pressure in both those with and without high blood pressure. An animal study found that taking a vitamin C supplement helped relax the blood vessels that carry blood from the heart, which helped reduce blood pressure levels.

vitamin c facts and benefits

In adults with high blood pressure, vitamin C supplements reduced systolic blood pressure by 4.9 mmHg and diastolic blood pressure by 1.7 mmHg, on average. While these results are promising, it's not clear whether the effects on blood pressure are long-term. Moreover, people with high blood pressure should not rely on vitamin C alone for treatment.

Helps Prevent Iron Deficiency

Iron is an important nutrient that has a variety of functions in the body. It's essential for making red blood cells and transporting oxygen throughout the body. Vitamin C supplements can help improve the absorption of iron from the diet.

It also assists in converting iron that is poorly absorbed, such as plant-based sources of iron, into a form that is easier to absorb. This is especially useful for people on a meat-free diet, as meat is a major source of iron. In fact, simply consuming 100 mg of vitamin C may improve iron absorption by 67%. As a result, vitamin C may help reduce the risk of anemia among people prone to iron deficiency.

In one study, 65 children with mild iron deficiency anemia were given a vitamin C supplement. Researchers found that the supplement alone helped control their anemia. If you have low iron levels, consuming more vitamin-C-rich foods or taking a vitamin C supplement may help improve your blood iron levels.

Unproven Claims of Vitamin C

While vitamin C has many scientifically proven benefits, it also has many unfounded claims supported by either weak evidence or no evidence at all.

Here are some unproven claims about vitamin C:

  • Prevents the common cold. While vitamin C appears to reduce the severity of colds and recovery time by 8% in adults and 14% in children, it does not prevent them.

  • Reduces cancer risk. A handful of studies have linked vitamin C intake to a lower risk of several cancers. However, most studies have found that vitamin C does not affect the risk of developing cancer.

  • Protects against eye disease. Vitamin C has been linked to reduced risks of eye diseases like cataracts and age-related macular degeneration. However, vitamin C supplements have no effect or may even cause harm.

  • May treat lead toxicity. Although people with lead toxicity appear to have low vitamin C levels, there is no strong evidence from human studies that show vitamin C can treat lead toxicity.

Food Sources Rich In Vitamin C

If you eat a diet rich in fruits and vegetables, you're probably getting enough. But if you're not sure, it might help to add any of these foods that are rich in vitamin C to your daily menu.

Oranges and Orange Juice

One 8-ounce glass of orange juice contains 120 milligrams of vitamin C, so it only takes one serving to get a day's worth of vitamin C. Oranges and orange juice are also good sources of potassium, folate, lutein, and vitamin A. Whole oranges are also a good source of fiber, but most of the fiber is lost when you drink the juice.


Grapefruits are related to oranges, so it's no surprise they're also high in vitamin C. One-half of a grapefruit has 45 milligrams of vitamin C, plus fiber, potassium, and plenty of vitamin A. Grapefruits are fairly sour, although ruby red grapefruits tend to be sweeter. You might want to add a light sprinkle of sugar or another sweetener before you eat them. You can also slice up grapefruits and add them to salads.

Green Peppers

One medium-sized green bell pepper has 95 milligrams of vitamin C, which is enough for one full day. Green bell peppers also deliver 8% of the daily value of vitamins A and K and 15% of vitamin B6. One whole green bell pepper contains just 24 calories. Green bell peppers can be sliced or chopped and added to a salad or used as an ingredient in a variety of dishes. Choose peppers that are bright green with unblemished skin.

vitamin c rich foods


One cup of raw chopped broccoli has 81 mg of vitamin C . That's not quite as much as orange juice, but a big serving of raw broccoli provides most of the vitamin C you'll need for one day. Depending on the cooking method, the amount of vitamin C reduced will vary.

One cup of chopped cooked broccoli has about 50 milligrams of vitamin C, an amount that's still impressive. To increase the amount of available vitamin C, you can reduce cooking time. For example, just lightly steam the veggie. One cup of broccoli (either raw or cooked) has about 30 calories.10 Broccoli is also an excellent source of calcium, potassium, fiber, vitamins A and K, and lots of antioxidants.


Luscious green kiwi—or kiwifruit—is an excellent source of vitamin C.8 One small fruit has more than 60 milligrams. Kiwifruit is also rich in potassium and fiber but low in calories. One fruit has about 40 calories.11 Kiwi is tasty all on its own or mixed with other fresh fruits and nuts for a healthy fruit salad.

Brussels Sprouts

Brussels sprouts are rich in vitamin C. Even after being cooked, one cup yields more than your daily requirement of C. They're also high in most vitamins and minerals, fiber, and antioxidants. Brussels sprouts are usually cooked and served as a side dish, but you can also slice or shred raw Brussels sprouts and use them in salad and slaw recipes.

Signs of Vitamin C Deficiency

Signs of vitamin C deficiency don't show up overnight. It usually takes at least a month of consistently low vitamin C consumption (less than 10 mg/day) for deficiency symptoms to develop. However, that doesn't mean your health is not suffering. If you don't have enough vitamin C, you can't be your best you. Also, if you notice any of the following, it could be your body telling you that you need more vitamin C:

  1. Rough, bumpy skin. Collagen is a protein necessary for skin cell reproduction, and vitamin C is a major player in collagen production. When we don't get enough vitamin C, the lack of collagen causes a buildup of keratin. This results in "keratosis pilaris," in which bumpy "chicken skin" forms on the back of the upper arms, thighs, or buttocks.

  2. Bright red hair follicles. Lack of vitamin C can cause the tiny blood vessels that deliver blood to rupture, causing the hair follicles to take on a bright red color. This usually indicates severe deficiency[1].

  3. Dry, damaged skin. With enough vitamin C, skin looks plump, moist, and healthy. A lack of it can lead to dry, damaged skin.

  4. Easy bruising. The low collagen caused by vitamin C deficiency weakens blood vessels, which can rupture to form bruises. This is an early sign of a vitamin C deficiency.

  5. Slow wound healing. Vitamin C not only prevents easy bruising but helps wounds heal. Low vitamin C levels slow healing.

  6. Painful, swollen joints. Joints contain collagen-reliant tissue that can be depleted by low levels of vitamin C.

  7. Bleeding gums and tooth loss. Vitamin C helps prevent gum tissue from becoming inflamed. Without enough, your gums may bleed easily, and your teeth may be at risk.

  8. Fatigue and poor mood. Lack of energy and mood disorders can be early signs of vitamin C deficiency.

  9. Spoon-shaped fingernails with red spots or lines. Brittle, concave, spoon-shaped nails (lower in the center than the top or bottom) can mean a deficiency of iron, vitamin C, or both. The addition of reddish spots or lines usually points to vitamin C as the problem.


Here are a few common questions that most people have about vitamin C.

vitamin c supplements

How much vitamin C do I need?

While there are some guidelines for vitamin C, it’s always important to consult with a nutrition before following any recommendations since each person is unique.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 known as the Recommended Dietary Allowance (RDA) and considers average daily nutrient intake from both foods and supplements. RDA recommendations for specific gender and age groups should meet the nutrient needs of 97–98% of healthy individuals. Here are the RDAs 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) - 66-75 mg

  • Adult women (aged 19 and older) - 90 mg

  • Adult men (aged 19 and older) - 85 mg

  • Pregnant women (aged 19 and older) - 85 mg

  • Breastfeeding women (aged 19 and older) - 120 mg

In addition to the RDA recommendations for vitamin C, the Food and Drug Administration (FDA) has issued a recommended Daily Value (DV). The DV 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. On food labels, this is displayed as %DV. Currently, the recommended DV for vitamin C for adults and children aged 4 and above is 90 mg, regardless of gender.

What happens if I take too much vitamin C?

Though vitamin c is an essential nutrient for your body, you can ingest too much of it. Although you cannot technically "overdose" on vitamin C, taking more than the maximum recommended amount of 2,000mg of vitamin C per day may cause uncomfortable side effects, including:

  • Diarrhea

  • Abdominal pain

  • Heartburn (or acid reflux)

  • Hemolysis (G6PD deficiency is present)

  • Nausea (or vomiting)

  • Headaches

  • Sleeping problems

  • Skin irritation and the formation of blackheads

Because vitamin C is a water-soluble vitamin, you're less likely to experience vitamin toxicity than you would with potassium, for example. This is because water-soluble vitamins dissolve in water and are absorbed in the small intestine. In other words, your body uses what it needs from the vitamin and discards the rest through your urine.

Vitamin C is water-soluble, so it's difficult to keep it in your system. According to the National Institutes of Health, consuming vitamin C in large doses over time could cause a reduced amount of vitamin B12 and copper, an accelerated metabolism, allergic responses, and the erosion of dental enamel.

natural vitamin c and synthetic vitamins

In addition, Vitamin C may negatively interact with other medications, including, but not limited to, chemotherapy drugs and cholesterol-reducing medications. For people with hemochromatosis, for example, too much vitamin C could be harmful and even life-threatening. Hemochromatosis is a condition in which the body produces too much iron, which can be toxic and cause damage to the heart, liver, and pancreas.

Find the Right Vitamins for You

Vitamin C is an integral part of your diet. However, it's only one piece of the puzzle. There are over 31 essential vitamins and minerals that need to be supplied to your immune system and body on a regular basis. Natural Care Chiropractic offers nutrition services to help you find the right balance of nutrition so that you feel healthy, have more energy, and can be your best self. Request an appointment with our highly qualified nutritionists to learn more about how they can help you find the right vitamins based on your specific deficiencies and needs.

4 views0 comments

Recent Posts

See All


bottom of page