Veggies and vegans are commonly labelled as pale, pasty and scrawny. As in all walks of life, there are those that fit that label but Phil and I certainly don't (I wouldn't mind the scrawny bit though). In fact I know more 'voluptous' vegans than scrawny ones.
There is also the misconception that vegans have to pay particular attention to their nutritional needs. Whilst it is certainly true that most vegans seem to be more naturally aware of the importance of a healthy diet, it is not because a vegan diet lacks nutritional content. In fact, it is quite the opposite and those that follow a non-vegan diet (and the ones that ask this more frequently) should often be the ones asking the same question of themselves.
Take iron as an example; the classic meat eaters excuse to keep eating meat. Vegan sources of iron include tofu, beans, pulses, spinach, whole grains, dried apricots, prunes, dates, millet, molasses and pumpkin seeds. Luckily I like all these foods. It is also fortunate for vegans that vitamin C helps the absorption of iron too as by nature vegans get a lot of that too!
I've been vegan for over 25 years and donate blood regularly. I was even recently asked to donate again before my normal call up due to low stocks in my blood group. Only once have my iron levels been low. The rest of the time they have been more than enough; hardly the result vegan naysayers would report of someone who has lived as a three headed, grass eating vegan for so many years!
So if you are veggie or vegan, don't be afraid to give blood if you want to. If you have a good rounded diet, there is no reason that your blood is less viable than anyone else.
Incidently, I have heard of some vegans (on-line) who for ethical reasons don't want to give blood. If anyone has an opinion on this I would be interested to hear it as, until recently that is a new one on me so I would like to learn more about that.