I received the following e-mail and thought I’d post a response publicly in case others had a similar question. The e-mail (edited for readability):
I haven’t eaten meat or chicken in a year and its been a few months with out dairy. I wanted to know, do I have to take a vitamin? I eat very well. Fresh veggies and fruit, beans, rice, certain fish, soy, seeds and nuts, whole grains, organic teas. I just don’t really understand why people take fish oils? And do I need to be taking them? Do you know of a book that tells you what you need to eat or take and why?
Before I respond let me say this: I’m not a nutritionist and my “advice” is only a guideline. You should check with your doctor or nutritionist before acting on any of my advice. Phew. Now that I have the legal stuff out of the way…
First of all, congratulations on what sounds like a big step toward eating healthier. It certainly sounds like you’re eating healthier than most people! Without knowing exactly what vegetables you’re eating and in what balance, it would be hard for me to say whether you’d need a vitamin, but my general thought on the matter is that if you’re eating a good variety of healthy foods you’ll get the nutrients you need. Since you’ve cut dairy, you will want to make sure that you’re getting enough vitamin B12 either through a supplement, fortified foods (fortified soy milk is a great source), or by adding some Red Star nutritional yeast to your foods.
With regards to fish, the main reason people are encouraged to eat fish or take fish oil is for the omega-3 fatty acids. I won’t get into a long discussion of what those are, how they work, and why they’re important, but fish, flax seeds (which can be ground and added to foods), and nuts like walnuts are all good sources. Obviously, as a vegetarian, I’d recommend going for the flax seeds as your primary source of omega-3s, particularly with some of the other health concerns with eating too much fish (high mercury levels, etc.).
I would suggest checking out Virginia Messina‘s site and read through some of the questions regarding vegetarian health and nutrition. Virginia’s also written a book titled The Vegetarian Way: Total Health for You and Your Family that may have the answer to some of your questions. You may also find The Vegan Sourcebook and VRG’s Vegan & Vegetarian FAQ helpful.