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A complete guide to Vitamin C

By Nutritionist Amanda Callenberg


  1. What is Vitamin C?
  2. Why is Vitamin C important?
  3. What causes us to be deficient in Vitamin C?
  4. What happens if we don't get enough Vitamin C?
  5. How much Vitamin C do we need?
  6. Where is Vitamin C found?
  7. How to make sure we get enough Vitamin C

Vitamin C benefits the body in multiple ways, from promoting a strong immune system to supporting healthy skin and bones. Many foods contain vitamin C, but due to the effects of modern day living, we are finding ourselves not getting the amount we need to meet our individual needs. Environmental toxins and air pollution that we are exposed to in the home and outdoors, life’s increased demands which leaves us in a constant state of stress, and chronic diseases are some factors that increase our body’s demand for vitamin C. The food we eat is also not of the same quality that it used to be, meaning that our nutrient requirements are always increasing, and this includes the need for vitamin C.

What is vitamin C?

Vitamin C, or L-ascorbic acid, is an essential water soluble nutrient that is naturally found in some foods. It is essential because, unlike most plants and animals, humans cannot produce it. It is a water soluble vitamin, which means the body cannot store it, so we need to get a constant supply through our diets.

Why is vitamin C important?

Vitamin C is widely recognised as a powerful antioxidant and its role in supporting the immune system. But it is also involved in many other processes and pathways in the body and affects a number of organ systems. Some of its main roles include: 

Vitamin C Antioxidant

Vitamin C is commonly known as an antioxidant. This means it is able to mop up free radicals that can cause oxidative stress and inflammation in the body. High levels of oxidative stress can be found in multiple organs including the heart, pancreas, kidney, brain and lung, and if not kept in check, can cause damage to these tissues and other tissues throughout the entire body.

Free radicals (AKA reactive oxygen species, ROS) are chemicals in the body that have been oxidised, ie., lost an electron, causing oxidative stress in the body. They are produced naturally in our cells and cause constant threat to our body. They are generated by things including metabolism of oxygen and food, exercise and exposure to environmental toxins and pollutants ie., cigarette smoke, chemicals, air pollution, radiation etc. These free radicals are missing an electron (electrons like to be in pairs) which make them unstable and highly reactive, oxidising (‘rusting’) everything that they come in contact with. They scavenge the body to find other electrons to steal so they can become a pair and stabilise.

Antioxidants, such as vitamin C, donate some of their electrons to free radicals, without turning into a free radical itself, which neutralises free radicals, acting a natural ‘off’ switch, therefore reducing the amount of oxidative stress in the body. In other words, they come in to help ‘clean up the mess’ that has been left behind from our natural bodily processes of metabolism, energy production and detoxification. Vitamin C’s antioxidant power also protects all of our cell structures, including proteins, lipids, DNA, RNA, mitochondria and cell membranes, from oxidising damage and giving our whole body a natural line of defence. If these free radicals build up in high amounts, it can damage cells and cause ageing and inflammation which can lead to chronic disease.

Vitamin C and the immune system

Vitamin C also plays an important role in immunity. It is needed for the production and modulation of immune cells that help protect the body from invading pathogens, and supports a number of other cellular functions of both the innate and adaptive immune systems. These systems help to prevent us from chronic diseases and also helps us to respond quickly to acute illnesses and infections.

Vitamin C also enhances another part of the immune system by strengthening its protective barrier function in:

  • Skin - vitamin C accumulates in the cells in the top layer of our skin (keratinocytes) preventing environmental oxidative damage
  • Lungs - vitamin C stimulates repair of the cells lining the surface of the lungs by rebuilding cellular tight-junctions, protecting it from damage.

Consuming extra vitamin C may be beneficial for those who do a lot of intense physical exercise as this causes the immune system to raise inflammation to support the repair and building of muscles.

Vitamin C and collagen formation

Vitamin C is required for the formation of collagen in the body. Collagen is the glue that ‘holds our bodies together’ and contributes to the maintenance of healthy blood vessels, skin, bones, cartilage, gums and teeth of which collagen is a vital structural component.

Vitamin C and energy production

Vitamin C is involved in the synthesis of L-carnitine which supports energy metabolism and helps to reduce fatigue and tiredness. It is also a vital nutrient for our adrenal glands which are responsible for regulating the body’s stress response. In cases of chronic stress, our adrenal hormones can become imbalanced, leading to fatigue. Vitamin C can also help to reduce the overall burden and energy demands on the body through its role in reducing oxidative stress.

Vitamin C and the nervous system

Vitamin C supports the normal functioning of the nervous system and our psychological function. It plays a role in the production of norepinephrine, our ‘get and and go’ or ‘fight or flight’ neurotransmitter. It plays a role in the production of dopamine and serotonin, important neurotransmitters that support our moods and motivation. It also protects our brains cells  from the harmful effects of oxidative stress via its antioxidant activities.

Vitamin C and iron absorption

Vitamin C helps to increase the absorption of plant sources of iron (non-heme iron).

Vitamin C and heart health

Vitamin C has been shown to improve blood flow which can reduce the risk of developing atherosclerosis and other cardiovascular conditions (a buildup of plaque in the arteries).

What causes us to be deficient in Vitamin C?

In the modern world, we are faced with many factors that leave us much more prone to having low vitamin C levels. These include:

  • Poor diet: Alcohol, refined sugar, caffeine, processed foods - can cause high urinary excretion of vitamin C or high production of free radicals, which increases our need for antioxidants
  • Toxins: environmental pollutants, cosmetics, domestic products, smoking - causes high levels of oxidative stress in the body and an increased need for antioxidants
  • Chronic illness (i.e. diabetes, autoimmune conditions) - produce high levels of free radicals and oxidative stress as well as lowers the body’s immune defences
  • Stress - vitamin C is needed to produce stress hormones, so the higher levels of stress we have, the higher our need for vitamin C
  • Fever, illness, infection - lowers the body’s defences and increases demands
  • Medications: aspirin and other non-steroidal anti-inflammatory drugs
  • Nutrient decline in foods due to soil depletion, intensive farming and long food storage
  • Iron deficiency

What happens when we don’t get enough Vitamin C?

As a water soluble vitamin, vitamin C does not stay in the body very long. In most cases, it is excreted within 24 hours. This means that it is absolutely necessary to get our vitamin C from external dietary sources or supplementation on a daily basis.

Signs and symptoms of vitamin C deficiency develop after a few weeks to months of vitamin C depletion. Severe deficiency in vitamin C, although very rare these days, can lead to the development of a condition known as scurvy, which is related to defects in connective tissues/collagen.

Vitamin C depletion

In early stages of vitamin C deficiency, usually seen within a few weeks to one month of inadequate intake, non specific symptoms include physical and mental fatigue, weakness, lethargy, irritability, weight loss, recurrent infections, poor wound healing, and mild muscle and joint aches and pains may develop.

Vitamin C deficiency

Symptoms of scurvy, related to defects in connective tissues, develop after within 8 to 12 weeks of irregular or inadequate intake. Signs and symptoms can include chronic inflammation and weak blood vessels (due to decreased collagen production). Weak blood vessels can lead to easy bruising, excessive bleeding, swollen and bleeding gums, loose teeth, coiled hair, and broken facial capillaries (spider veins). Other signs and symptoms include anemia, muscle and joint pain, bone pain, mood changes, and depression.

How much Vitamin C do we need?

The recommended daily vitamin C intake varies depending on age, sex, lifestages, individuals lifestyles and our state of health. For example, if we are fighting an illness or infection, our requirement for vitamin C increases dramatically as we need to produce enough immune cells to help the body fight the infection (immune cell production is vitamin C dependent). Likewise, if we are constantly exposed to environmental pollution or toxins, we need large amounts of vitamin C’s antioxidant activity to come in and sweep up the free radicals and reduce oxidative stress in the body to prevent inflammation and tissue damage.

The recommended requirement of vitamin C for adults is between 75mg in women and 90mg in men per day. This increases to 85mg for pregnant women and 120mg in breastfeeding women.

Where is Vitamin C found?

Vitamin C is present to some degree in most fruits and vegetables, however, some types of fresh produce have more vitamin C than others. Contrary to popular belief, many fruits and vegetables contain more vitamin C than oranges and other citrus fruits.

Foods that contain the vitamin C include: papaya, bell peppers, guava, Brussels sprouts, broccoli, oranges, strawberries, kiwi, pineapple and cantaloupe melon, citrus fruits.>

These foods are best eaten raw and soon after preparation as cooking and exposure to oxygen can reduce the vitamin C content by about 25%.

How to make sure we get enough Vitamin C

Although it is possible to get enough vitamin C from foods, our modern lifestyles can make it difficult to consume the amount of fresh fruit and vegetables we need to prevent deficiency. If you are very physically active, under high amounts of stress or even just exposed to outside air pollution on a daily basis, your body’s needs for vitamin C increase so you would need to consume a large amount of fruits and vegetables to keep your blood levels within a steady range.

One of the easiest ways to ensure you are getting enough vitamin C to support all your body’s systems that require vitamin C is through supplementation. Zooki Liposomal Vitamin C is highly bioavailable and is a quick and easy way to make sure you are getting your daily needs and topping what may be lost.

What is Liposomal?

Liposomes encapsulate the vitamin C molecule inside its phospholipid bi-layer (the same makeup as our human cells), allowing it to merge with our cells and deliver the vitamin C directly into our cells (speeds up the rate our cells absorb Vitamin C from the blood). This outer layer (phospholipid) protects the vitamin C inside from damage that might occur during the digestion process.

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