Vitamin C is also a water-soluble vitamin which means it’s not stored in the body so is required to be taken on a regular basis.
Vitamin C has a diverse range of important functions in the body, arguably one of the most important of which is supporting both the health and function of the immune system. So how exactly does vitamin C support immunity?
How vitamin C supports immunity
Vitamin C contributes to our immune defences by supporting various cellular functions of both the innate and adaptive immune systems. Vitamin C supports the integrity of the barriers of the body, including the skin, the largest barrier to infection, as well as by supporting the health of the epithelial barriers such as the mucosal membranes of the nose, throat and intestinal linings.
Vitamin C is also a powerful antioxidant, scavenging free radicals that form in the body and by doing so protecting the body from environmental oxidative stress.
Finally, vitamin C accumulates in phagocytic cells, such as neutrophils. Phagocytes are a type of white blood cell that engulfs foreign pathogens as they enter the body and assists in the process of destroying them. Vitamin C levels in white blood cells have been shown to be tens of times higher than in plasma, which may indicate the functional role vitamin C plays in these important immune system cells[1].
How much vitamin C do you need?
The Recommended dietary intake (RDI) each day of vitamin C across the various ages and stages of life is set out in the table below:
|
Age |
Vitamin C RDI[2] |
|
0-6 months |
25mg |
|
7-12 months |
30mg |
|
1-8 years |
35mg |
|
9-18 years |
40mg |
|
19-70 years |
45mg |
|
In pregnancy |
60mg |
|
During lactation |
85mg |
Gastrointestinal effects are the most common side effects associated with acute, high doses of vitamin C given over a short period of time, the most common symptom of which is diarrhoea.
Vitamin C and where you can get it
Fruits and vegetables are the best source of vitamin C. While citrus foods like oranges and grapefruits are rich in vitamin C, this important vitamin can also be found in abundance in a variety of other fruits and vegetables. Some of the best sources of vitamin C and the amount of vitamin c per serve can be found in the table below:
|
Best dietary sources of vitamin C |
mg of vitamin C per serve |
|
|
Red capsicum, sweet, raw, ½ cup |
95 |
|
|
Orange juice, ¾ cup |
93 |
|
|
Orange, 1 medium |
70 |
|
|
Grapefruit juice, ¾ cup |
70 |
|
|
Kiwifruit, 1 medium |
64 |
|
|
Green capsicum, sweet, raw, ½ cup |
60 |
|
|
Broccoli, cooked, ½ cup |
51 |
|
|
Strawberries, fresh, sliced, ½ cup |
49 |
|
|
Brussels sprouts, cooked, ½ cup |
48 |
|
|
Grapefruit, ½ medium |
39 |
|
|
Broccoli, raw, ½ cup |
39 |
|
|
Tomato juice, ¾ cup |
33 |
|
|
Rockmelon, ½ cup |
29 |
|
|
Cabbage, cooked, ½ cup |
28 |
|
|
Cauliflower, raw, ½ cup |
26 |
|
|
Potato, baked, 1 medium |
17 |
|
|
Tomato, raw, 1 medium |
17 |
|
|
Spinach, cooked, ½ cup |
9 |
|
|
Green peas, frozen, cooked, ½ cup |
8 |
|
How to get more vitamin C for your immune system
When dietary intake of vitamin C is inadequate, supplementing with vitamin C can help to provide your body with the extra vitamin C it may be needing.
Herbs of Gold Vitamin C 1000 Plus is a high-potency vitamin C complex containing citrus bioflavonoids and zinc to support immune system health. This high-strength formula provides 1g of vitamin C per tablet in a low acid form, working as both an antioxidant and to support healthy immune system function.
Herbs of Gold Zinc Forte + C provides vitamin C in powder form in combination with zinc and supported by important cofactors vitamin B6, betacarotene and magnesium. Available in a delicious raspberry flavour, this product is vegan-friendly and suitable for use from 4 years and up.
[1] Hemilä, H. (2017). Vitamin C and infections. Nutrients, 9(4), 339.
[2] National Health and Medical Research Council. (2017). Nutrient Reference Values for Australia & New Zealand. Vitamin C. https://www.nrv.gov.au/nutrients/vitamin-c
