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Eat your greens. Get your vitamin B-12. Eat sources rich in zinc. Find sources of omega-3 fatty acids.

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Dark, leafy greens, such as kale or turnip greens, contain large amounts of calcium, an essential nutrient to keep your bones strong and healthy. The government recommends you get 1,000 milligrams of calcium per day. A cup of raw kale has 137 milligrams of calcium. Vitamin B-12 is important in maintaining healthy blood cells. It will also help keep the iron up in your blood. If you become anemic, you may not have the strength to lift weights.  In the same vein, it's important to get enough iron in your diet to keep you from being anemic. Iron is in peas and lentils, as well as dark, leafy greens. One of the best ways to get both iron and vitamin B-12 is through enriched cereals. You'll also find vitamin B-12 in nutritional yeast.  The government recommends you get 6 micrograms of vitamin B-12 daily and 18 milligrams of iron per day. Most enriched cereals more than cover your vitamin B-12 needs in a single serving, some having as much as 28 micrograms per serving. Read the labels to make sure you are getting enough. A cup of lentils (already cooked) will provide you with 37 percent of your daily value of iron. Zinc helps keep your body healthy. Therefore, it's important to get enough in your diet so that you can continue to build muscle mass.  Beans, enriched cereals, and pumpkin seeds are a great way to get enough zinc in your diet. You should get at least 15 milligrams of zinc per day. To put this amount in perspective, you get 2.57 milligrams of zinc from 1/4 of cup of pumpkin seeds.  After testing your zinc blood levels, you may find that a zinc supplement would benefit you. Omega-3 fatty acids help keep you heart in good shape, your body's most important muscle.  For vegans, the best sources of omega-3 fatty acids are flaxseed, walnuts, and soybeans. Certain oils are also good sources, such as canola and soy.  The American Heart Association recommends eating sources of omega-3 fatty acids at least twice a week.