The average American consumes too much sodium and too few essential nutrients like dietary fiber, vitamins and minerals, says the Centers for Disease Control and Prevention. One sodium-free option for boosting the flavor and nutrition of your meals is to use onion power. Consisting of ground dehydrated onion, onion powder contains dietary fiber, manganese, calcium and vitamin C. A 1-tablespoon serving of onion powder is roughly equivalent in flavor to a 1/2-cup serving of chopped raw onion. Use it to lend a mild onion flavor to soups, sauces, pasta salads, dressings or dips, or mix it into rubs for chicken, beef, pork or seafood. Dietary Fiber A 1-tablespoon serving of onion powder contains about 1 gram of dietary fiber. This amount supplies 2.6 percent of an adult man's daily requirement of fiber and 4 percent of a woman's recommended daily intake. Onion powder has as much fiber per tablespoon as a half-cup serving of cooked cauliflower, 1 medium-sized tomato or 1 cup of cubed, raw cantaloupe. A diet that regularly includes a high intake of fiber may decrease your risk of stroke, high blood pressure, cancer, heart disease, obesity, diabetes and high blood cholesterol. Manganese The Institute of Medicine's Food and Nutrition Board advises that adult men need 2.3 milligrams of manganese daily, while women need 1.8 milligrams. A 1-tablespoon serving of onion powder contains 0.09 milligrams of the mineral, fulfilling 4 percent of a man's RDA and 5 percent of a woman's. The body needs manganese to aid in energy metabolism, to help regulate blood sugar levels and calcium absorption and to synthesize bone tissue, hormones, proteins involved in blood coagulation and the antioxidant enzyme superoxide dismutase. If you don't consume enough manganese, you may be more likely to develop arthritis, osteoporosis or diabetes. Calcium Calcium's primary role is to support the growth, development and maintenance of bones and teeth, though it is also needed to support the function of the muscles and nerves. Other nutrients, including vitamin D, vitamin K and magnesium, require calcium's presence in order to be absorbed properly. Every tablespoon of onion powder contains 26 milligrams of calcium, or nearly 3 percent of the required daily intake for adults between 19 and 50 years old. Eating plenty of calcium-rich foods may help prevent high blood pressure, osteoporosis, obesity and high blood cholesterol. Vitamin C Onion powder has 1.6 milligrams of vitamin C in every 1-tablespoon serving. For a man, this is 1.7 percent of his daily vitamin C requirement; for a woman, this amount supplies 2.1 percent of her vitamin C RDA. Vitamin C is an antioxidant that can inhibit the DNA-damaging ability of free radical compounds. It also supports bone health, aids in the production of collagen and promotes the healing of wounds. Without enough vitamin C in your diet, you may have a higher risk of cancer, age-related macular degeneration, osteoarthritis, hypertension and heart disease.