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Vitamin C

July 14, 2020

Vitamin C

Last #NutritionTipTuesday we looked at the water soluble B vitamins so today we are looking at the other water soluble vitamin, vitamin C. Vitamin C has many important roles in the body including:

  1. Antioxidant properties - Antioxidants are molecules that boost the body’s immune system by protecting cells from harmful molecules called free radicals. Free radicals can accumulate and cause oxidative stress and inflammation which can cause chronic diseases such as heart disease. Consuming more vitamin C can increase your blood antioxidant levels by up to 30% which helps the body’s natural defences fight inflammation. This may also help those with dementia, which may be caused by oxidative stress and inflammation of the central nervous system.
  2. Boosts immunity - Vitamin C has many roles when it comes to boosting the body’s immunity such as:
    1. Helping support cellular immune response – Vitamin C helps activate natural killer cells, macrophages and antigen-specific T-lymphocytes. These cells attack foreign bodies so they are unable to multiply.
    2. Enhancing the function of phagocytes – Phagocytes are a white blood cell that surrounds pathogens and other foreign bodies and digests them using enzymes.
    3. Enhancing cytokine production – cytokines are communication proteins released by certain white blood cells that promote the immune response by transmitting information to other cells
    4. Supports the activity of natural killer cells – these are small lymphocytes that can directly attack damaged cells and kill them so they are unable to multiply.
    5. Protecting white blood cells from damage from free radicals
    6. Being an important part of the skins defence system and helping strengthen the skin’s barriers.
  3. Needed for normal growth and development – Vitamin C helps form and maintain bones, skin, and blood vessels and plays an important role in the production of L-carnitine, some neurotransmitters and collagen. Collagen, is the main component of connective tissue and is a vital component of tissues such as tendons, ligaments, skin, cartilage and bones.
  4. Helps the body absorb iron - iron has a variety of functions in the body and is essential for making red blood cells and transporting oxygen throughout the body. Vitamin C helps convert iron that is poorly absorbed, such as plant-based sources of iron, into a form that is easier to absorb. This is particularly beneficial for people who do not eat meat. As a result, vitamin C may help reduce the risk of anaemia among people prone to iron deficiency.
  5. May help manage high blood pressure – taking a vitamin C supplement has been shown in short term studies to reduce systolic blood pressure by ~3.8 mmHg and diastolic blood pressure by ~1.5 mmHg in healthy adults and reduce systolic blood pressure by ~4.9 mmHg and diastolic blood pressure by ~1.7 mmHg. Additionally, vitamin C may also help relax the blood vessels from the heart which helps reduce blood pressure levels.
  6. May help lower risk of heart disease – in addition to helping manage high blood pressure, vitamin C may also reduce triglyceride levels, reduce LDL (bad) cholesterol levels.
  7. May help prevent gout – Gout is a type of arthritis that causes painful inflammation of the joints. Vitamin C may help protect against gout attacks by reducing the uric acid in the blood which, when present at high levels, may crystallise in the joints.

Vitamin C may also help protect against cancer, eye disease, lead toxicity and the common cold.

Food Sources

Since the body does not store large amounts of vitamin C, it is recommended to eat fresh fruits and vegetables every day to ensure you are getting enough. Vitamin C rapidly breaks down when exposed to heat, so raw fruits and vegetables are better sources than cooked ones.

Smash back one of our salads or high vitamin C smoothies such as the Nut Job, Mulberry Blue or Breakfast Smoothie and you’ll definitely be well on your way to getting your serving of vitamin C for the day.

Fruits with the highest sources of vitamin C include:

  • Guava
  • Cantaloupe
  • Citrus fruits and juices, such as orange and grapefruit
  • Kiwi fruit
  • Mango
  • Papaya
  • Pineapple
  • Berries
  • Acai

Vegetables with the highest sources of vitamin C include:

  • Broccoli, Brussels sprouts, and cauliflower
  • Green and red capsicums
  • Spinach, cabbage and other leafy greens
  • Tomatoes and tomato juice


The recommended daily intake for vitamin C is 75 mg for women and 90 mg for men but smokers should consume an additional 35 mg per day, since tobacco reduces the absorption of vitamin C and increases the body’s use of vitamin C.

Vitamin C toxicity is very rare, as you expel excess vitamin C in the urine, but some find that taking supplements containing more than 2,000 mg per day can lead to an upset stomach and diarrhoea. This can also depend on the type of vitamin C taken - lyso-spheric vitamin C is handled better by the body and macro-dosing vitamin C, when you are sick or at risk for getting sick is unlikely to have any significant negative effects and is pretty common practice to help boost the immune system.


Deficiency can occur in those who struggle to get enough fruit and veggies in their diet. The most common risk factors for vitamin C deficiency are poor diet, alcoholism, anorexia, severe mental illness, smoking and dialysis.

Symptoms of vitamin C deficiency include:

  • Poor immunity
  • Iron deficiency
  • Fatigue
  • Weight gain
  • Chronic inflammation
  • Oxidative stress
  • Bumpy and/or dry damaged skin
  • Easy bruising
  • Slow healing
  • Painful and swollen joints
  • Weak bones
  • Bleeding gums
  • Fingernails with red spots or lines

Next time we are looking at fat soluble vitamins! Stay tuned!