All the fresh, raw, organically grown food you can stomach does not make for a healthy diet if you’re not getting all the nutrients your body needs for your stressfull and exhousting life in student campus.

A healthy diet is a balanced diet. “There is no one food that is of absolute necessity for life,” says Sheah Rarback, a dietician and spokeswoman for the American Dietetic Association. Neither vegetables nor meat nor grains alone provide complete sustenance.

If you abstain from meat or other animal products, you must find the nutrients abundant in those foods elsewhere. “Just because somebody doesn’t drink milk doesn’t mean the body no longer needs calcium,” says Leslie Bonci, a dietician and director of sports nutrition at the University of Pittsburgh.

Dairy products are an important source of calcium, so those who go vegan should find another way to get this essential mineral. A calcium deficiency can have bad consequences. “The risk may not be immediate,” Rarback says, but in the long run, a diet low in calcium makes you prone to osteoporosis. Calcium deficiency can cause high blood pressure, too. “It’s not just about bone,” Bonci says. Beans, almonds, dark greens, and fortified orange juice provide a lot of calcium.

Swearing off meat can play havoc with your immune system if you aren’t careful. Protein and zinc, both plentiful in meat, are needed for immune function. You can get zinc in your diet by eating whole grains, beans, and lentils. For protein, “I recommend soy,” Rarback says.

Tofu is not your only option. Prepared soy products that imitate meat are appearing in supermarket freezer cases across the country. You can enjoy soy burgers — which don’t taste much like beef burgers, but are scrumptious, nevertheless — soy nuggets that taste almost exactly like chicken nuggets, soy hotdogs, and even soy Italian sausage.

Vegans should watch out, because some of these products are made with milk and cheese, although for vegetarians, they’re “another nice option,” Bonci says.

Vegetarians and vegans also need to think about iron. Meat, especially red meat, and egg yolks are major sources of iron. If you don’t get enough, you can develop iron deficiency anemia, a condition in which the blood contains too few red blood cells. Red blood cells carry oxygen. When your blood can’t provide enough oxygen, you become fatigued, weak, and short of breath.

In women, iron deficiency anemia is often caused by blood loss through menstruation. The body needs iron to build red blood cells. If you have low iron reserves and you bleed heavily, you won’t be able make new red blood cells.

In young children, simply not eating enough iron can cause anemia because their growing bodies need more of it. If you’re raising your kids vegan or vegetarian, make sure they get enough. Iron deficiency in children can cause developmental problems.

Fortified cereals, oatmeal, seaweed, and soy are good alternative sources of iron.

Vegetarians and vegans aren’t the only ones who are missing pieces of the food pyramid. Most Americans gobble up bread, cheese, and meat, but ignore fruits and vegetables. While you can find nutrients common in animal products elsewhere, it’s tough to squeeze fruit and vegetable nutrients, like vitamin C and folate, from other sources.

Don’t think you can replace veggies with a vitamin supplement. “The name suggests how you should use it,” Rarback says. “There is much more in food that has been bottled in a pill.” Plants contain phytochemicals, which are not nutrients, per se. They’re naturally occurring chemicals that are believed to prevent disease in people.

To get the nutrition you need from fruit and vegetables, you don’t have to eat the whole cornucopia, Brussels sprouts included: Just eat a lot of what you like. “Even one or two is better than eliminating an entire category altogether,” Bonci says.