Qns: How much Vitamin C is too much...and is there anything special I need to be looking for?

The RDI for Vitamin C as detailed by the Ministry of Health is 45mg.  Research deduced that 60mg is the minimum amount required to avoid deficiency and therefore scurvy, if Vitamin C ingestion should stop.  However, 5 servings of fruit and veg per day will give you anywhere from around 200-400mg of Vitamin C so the actual amount of Vitamin C that we ‘should be consuming' is a little confusing. 

Many nutritionists and naturopaths will recommend 250-400mg of Vitamin C per day, while another commonly recommended dose is 500 - 1000mg per day.  Because it is water soluble, it is difficult to overdose on Vitamin C, however doses over 2000mg can cause stomach upsets and diarrhea (again, dosage would depend on your tolerance).  High levels act as a diuretic also, so be wary if you're taking over 2000mg and also on other diuretics or if you have kidney problems.

Here are some common foods and their Vitamin C content.

100g fresh Guava = 230mg

100g Red capsicum = 170mg

100g Brussell Sprouts inner leaves = 97mg

100g Kiwifruit = 92mg

100g Raw Cauliflower = 60mg

100g orange = 35mg (1 whole orange = 45mg)

You can see that it's relatively easy to get the RDI of Vitamin C and that by eating 5+ a day, you are getting a sensible dietary amount of Vitamin C around the 200-400mg mark.  In my opinion this intake level would also be suitable when looking at supplementation.

Vitamin C is a water soluble vitamin so is not stored in the body, and is also not made in the body so we need to get it from our diets. There is a saturation level where the body will excrete excess Vitamin C.  The saturation level is thought to be around 60mg also In any case, so if you're taking 250, 500 or even 1000mg all in one go chances are, much of it is going down the drain.  If you took the 400mg example, you'd be best to look at around 50-100mg taken a few times throughout the day.

The best form of Vitamin C is in an esterified form as it is absorbed faster and used more efficiently, some Vitamin C's are artificially sweetened and full of colourings which may effect those with a sensitivity.

Smoking, toxins, and alcohol deplete our bodies of Vitamin C, and sugar ‘fights for space' with it.  If you are barraging your body with any of these then you may want to supplement with Vitamin C to help protect against the oxidative damage from these.

Vitamin C is a powerful antioxidant and protects HDL (good) cholesterol, thereby it can be useful in a cholesterol lowering diet, it is used in the production of collagen, an immunity booster and is needed for proper wound healing.  It is usually found in conjunction with Vitamins A & E.

Most vitamin C supplements will tell you if they contain sugar (looking out for things like glucose, dextrin & maltodextrin) or if they contain artificial sweetner (aspartame, acesulphane K).  There is one product which doesn't declare either and we can only assume it is natural.  Ester-C is usually in capsule/pill form and not to be chewed so contains none of the above.


Stacey
22 March 10