The immune system helps your body fight off infection, but its response diminishes with age. You can boost your immunity by following these steps:

Eat a healthy diet. A wide variety of fruits, vegetables, and whole grains provides necessary vitamins and minerals.

Exercise daily. Get at least 150 minutes per week of moderate-intensity exercise, or 75 minutes of vigorous activity. Muscle-strengthening exercise twice a week affords additional health benefits.

Reduce stress. When you’re under stress, your body releases certain hormones, including cortisol. If this goes on too long, it will open the door to damaging chronic inflammation. In addition, stress decreases production of white blood cells, called lymphocytes, that fight off infection. High stress levels can also cause anxiety and depression, which dampen the immune system.

Sleep well. Get at least eight hours of sleep each night. Sleep deprivation suppresses the immune system. If you have trouble sleeping, try taking a low dose of melatonin and increase until it works for you.

Take these supplements daily.

• Vitamin C: 1,000 - 2,000 mg

• Vitamin D: 2,000 IU

• Vitamin E: 400 IU

• Zinc: 20 mg

• Garlic: 1 or 2 cloves, or 600 mg to 1,200 mg

• Cimetidine: 800 mg to 1200 mg daily in divided doses. Known as Tagamet, this heartburn medication has immune-boosting effects.