I have knee issues and take glucosamine sulphate 1000mg tablets and high strength cod liver oil tablets-I was taking 500mg but a nurse told me to up my doseage-they seem tom be helping, that along with the physio.

I too take glucosamine, mainly for my knees but also general getting old(er) joint suppleness. I also have some all round vitamin tabs I keep for occassions of illness when you have to force yourself to eat anything, just to keep my vitamin levels up. I think the supplement i take most of is tomato ketchup, I do seem to go through a lot.

Hi all,

From what I've read, Glucosamine is generally good, with no side-effects. The same can't be said for other supplements. Vitamin A, for instance, is very bad for you (vitamin A toxicity may result. This can lead to nausea, jaundice, irritability, anorexia (not to be confused with anorexia nervosa, the eating disorder), vomiting, blurry vision, headaches, hairloss, muscle and abdominal pain and weakness, drowsiness and altered mental status.), although if you only overdose on vitamin A by eating too many carrots, the o/d will come out by turning bright orange!
If you're eating a varied diet, you shouldn't need to be taking vitamin supplements unless there is a specific reason (e.g., Iron for excessive menstrual bleeding)
I can remember one guy (trying to win the prize for first man-powered flight - a few years ago) taking one particular vitamin (sorry, can't remember which one) whose only documented use was improved fertility - in rats!

Who recommended that?

Hi Dan,

My "googling" produced
1/ "The second study concluded that blood vitamin C levels decreased in athletes ingesting 100 mg per day. A dietary intake of 300 mg/day maintained blood levels of the vitamin"
2/ "Levels within the body that are 1500 mg or less will result in no urinary excretion of vitamin C (13). As levels increase above 1500 mg the reabsorption efficiency of the kidneys decreases. Thus, body pool levels from 1500 to 3000 mg relate to tissue saturation of the vitamin"
Reference:http://www.exrx.net/Nutrition/Antioxidants/VitaminC.html
What this says to me is:
1/ You (as an athlete) should be taking 300mg per day (Three hundred)
2/ The figure of 3000mg (Three thousand) is the level at which your tissues will be SATURATED with the vitamin.

Fortunately, Vit C is soluble, so you can dispose of it in the time-honoured fashion. However, forcing your kidneys to dispose of 700mg per day can't be doing them any good.

Glucosamine for me.

but doesn't vit C also increase the bodys ability to store/absorb iron?

personally i take glycosamine and vit C and Zinc.

its the zinc bit that actually has a greater affect on strengthening your immune system. this was found as part of a study into ME and how to help people with it avoid long setbacks due to colds.

Yes, Vit C helps with iron absorption. My point, all along, has been that a RDA of 100mg is recommended for Joe Public, with 300mg for athletes. 300mg is attainable with nothing more than your "5-a-day". You don't need to pump yourself full of extra Vit C.

However, Vit C is not the most worrying vitamin, any excess (and once you go over 3000mg in your system, that's any excess over your RDA) can be flushed out through the kidneys. Other vitamins and supplements (Vitamin A, for example) CAN'T be flushed out of the system, and WILL cause problems.