Recharge Your Body's Defense System

The Mouth Test for Vitamin B6

Vitamin B6 also strengthens your immune system. Not having enough B6 can cause confusion, depression, irritability and sores on the mouth or tongue. Low levels of vitamin B6 have been linked to chronic inflammation in the body.

What to do: At home, check your mouth in a mirror. Start with the outside of your mouth and look around its edges for signs of cracking. Then, open your mouth wide and look for any sores (don't forget to peek under your tongue—you may need to the help of a flashlight). If you notice any sores, it could mean that you aren't getting enough vitamin B6. There are ample sources of vitamin B6: chicken, fish, kidney, liver, as well as whole grains, nuts, and legumes.

The Skin Test for Vitamin A

This important vitamin helps your body form and maintain healthy skin, teeth and bones. It also helps your immune system stop and kill germs as soon as they come in contact with your body.

What to do: This test will require you to do a full-body examination. Check for dry, rough and cracked skin, brittle hair, and peeling or splitting nails. These may indicate a deficiency in vitamin A. You can find ample sources of vitamin A in these vegetables: broccoli, spinach, turnip greens, carrots, squash, sweet potatoes, and pumpkins.

More Health Advice

• Dr. Oz's 5 simple ways to fight allergies
• How your emotions affect your immune system
• Cold and flu tips from Dr. Oz