In Nutrition, of the diff. types of vegetarian diet, which kind may tend to be difficient in some nutrients?

Of the various vegetarian diets, the one that has the most risk of nutritional deficiency if not managed correctly is the Vegan diet. Vegans eat no animal products at all, no butter, bacon, lard, eggs, cheese, nothing that comes from an animal even if it is a little lard in a tortilla or butter in a cookie recipe. Now lacto-ovo vegetarians eat eggs and milk and so they get the vitamin B12 that the vegans are missing as B12 is only found in animal products. A vegan diet can be very healthy if managed correctly and a vitamin B12 supplement is taken on a regular basis. The healthiest diet in my opinion, is one that has the vegetarian balance of vegetables, fruits, grains and plant protein sources such as beans, lentils and tofu etc but that also adds in fish a couple times a week. This is more healthy than just being a vegetarian because of the properties of the omega 3 fatty acid (an oil) found in fish. So bake, broil, and BBQ your fish to get this healthy oil, no deep fat frying or you will destroy this little health miracle found in fish.

You can almost get everything you need from a vegetarian diet but Vegans many times need to take supplements to get some vitamins and minerals not found in plant food sources.

Many non meat eaters, especially women, may need to take iron supplements if they don't eat enough iron rich veggies.