I do not yet have children but I am a vegetarian. I am curious to know how vegetarians, and vegans, address the issue of nourishment. If it helps, I am vegetarian more for ethical reasons than health concerns.
EDIT: Oops, typo. I am vegetarian but I am considering going vegan.
Children need the same nutrients as adults do, though usually they need more of them. If you've been vegetarian for more than a year, and your blood tests are fine, they can eat what you eat, and should be ok.
A lot of people think that it is difficult to get enough protein or iron without eating animal products, including meat and dairy. This is not true. Eating a combination of grains (rice, wheat, oats etc.) and legumes (lentils, chickpeas, beans of any sort etc.) will provide protein, iron and some other minerals (magnesium for instance).
B group vitamins occur naturally in avocadoes, as well as all sorts of nuts. There is a specific issue with B-12, which isn't easy to come by from a plant source. Personally, I take supplements, because I'm lazy. It is also found in almost every songle fortified breakfast cereal, and a host of other things easily available for kids.
There are plenty of health reasons not to eat animal products, and these are doubly true for children. It's not difficult or complicated, as long as you know what you're doing.
Are you adequately nourished? Do you take supplements at all to compensate for your dietary choices that result in reduced levels of required nutrients? Do your ethics also extend to taking in supplements that are animal-sourced?
There are vegans or vegetarian who eat very well, widely and balanced, there are carnivores who eat badly, so I don't think it's merely a question of what you choose to omit or include on a general level.
Pregnant mothers often do feel the need to eat strange things and the common interpretation of this is that their body is telling them that something is missing. I have a friend who is similarly ethically vegetarian, yet she ate meat through her two pregnancies as getting various minerals and proteins from meat was the easiest way to do it and her aim of a healthy child was more important to her for those few months than her vegetarianism.
As with anything that might impact on your (and your baby's) health, I would suggest regular monitoring before and during the pregnancy - and definitely tell your doctor/midwife/etc. about it, they'll have seen it before.
I'd ensure you got professional advice before committing your children to a vegan diet. Personally, I have seen the article above before, and some others, indicating it's hard to ensure a child can get an adequate enough supply of nutrients to maintain healthy growth.
My wife was a vegetarian and we made a conscious decision our kids would not be, and that once they understood why my wife was a vegetarian, they could make their own minds up.
I have found articles outlining that sometimes, with a growing child, it is hard for them to maintain a good enough vegan diet due to the sheer weight, amount, of food they have to eat in order to maintain healthy growth.
I am not trying to be too overly moralistic here, but as with religion and other choices in life, please ensure you're doing this for the children, and not for yourself.
Anecdotally, I grew up with a vegan boy at school and he was forever ill, as was his curiously vegan dog.
http://www.vrg.org/nutshell/kids.htm
Nutritional risks
Any potential risks of vegetarianism seem to be related to the type of vegetarian diet, i.e. the foods that are excluded. Vegan diets are more likely to be associated with malnutrition, whereas children eating a lacto-ovo-vegetarian diet consume diets closer to recommendations than children whose diets include meat. Their pre-pubertal growth is at least as good as children consuming meat. In general, the greater the degree of dietary restriction, the greater the risk of nutritional deficiency." http://www.health.vic.gov.au/nutrition/child_nutrition/vegetarian.htm
http://www.power4health.org/Principles/Nutrition/ChildVeggies.html
In this article from Ehow.com - http://www.ehow.com/facts_5161650_proper-nutrition-vegetarian-kids.html, the author cite examples on how you can ensure that proper nutrition is given for vegetarian kids. She also mentioned what food supplements to use, and how to ensure that the child can still get the right amount of nutrients.
