A healthy immune system is vital to protecting the body against bacterial and viral infections, as well as other diseases. Although scientists still aren't sure exactly how the immune system works or how it breaks down, research has shown that certain vitamins and nutrients are especially helpful in bolstering your ability to stay healthy. Ideally, you'll get these important nutrients in your diet, but most multivitamin supplements contain enough to make up for what you might miss in the foods you eat.
Vitamin C
The old idea that the vitamin C in a glass of orange juice would keep you from getting a cold may not entirely hold true, however, healthy vitamin C levels in the body can protect against the severity of colds, pneumonia and other infections, according to the Cleveland Clinic. Vitamin C, a powerful antioxidant that has been associated with protective effects against cancer, joint diseases and other conditions, can be found in citrus fruits (and juices), as well as broccoli, strawberries and bell peppers.
Vitamin B6
According to the National Institutes of Health (NIH), Vitamin B6 is critical in proper immune system functions for older people, and the amount needed to reverse immune system impairments in older adults is less than the recommended daily allowance of 1.7 mg for men and 1.5 mg for women over 50. For men and women under 50, the RDA is 1.3 mg. Good sources of vitamin B6 include whole grains, milk, eggs and vegetables such as carrots and spinach.
Zinc
Zinc is an essential element that is found in foods such as beef and turkey, as well as vegetarian sources such as chickpeas, cashews, pecans and green peas. Zinc is such a proven immune builder that it is often included in cough drops to help fight colds and other infections.
Vitamin D
A study by the Linus Pauling Institute at Oregon State University, released in August 2009, found that the ability of vitamin D to regulate antibacterial proteins has been so instrumental in the immune system it has survived more than 60 million years of human evolution. Vitamin D also helps protect against some forms of cancer and some autoimmune diseases. It's also vital in helping the body absorb calcium. Good sources of vitamin D include salmon, tuna, skim milk and eggs.
