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While you are treating your dry scalp from the outside with conditioner or oils, it's just as important to treat it from within, too. Staying hydrated by drinking enough water to keep your skin healthy and hydrated. Try to drink at least eight 8-oz glasses of water daily. Vitamin deficiencies may be causing your dry scalp. Make sure you are eating a well-balanced diet and getting plenty of vitamin B (especially B6 and B12) from fruits, vegetables, and whole grains. Omega-3 fatty acids are also important in supporting a healthy, hydrated scalp. Omega-3s are found in fatty fish, nuts and seeds, and oils. You can supplement vitamin B with flaxseed oil, zinc, or selenium and take fish oil supplements to increase Omega-3s. Always talk to your doctor or pharmacist before beginning a new supplement. Sometimes, a dry, itchy scalp is caused by something you're allergic to in your shampoo or other hair products. To test the theory, try picking hair products that are free of dyes and scents to see if that helps keep you from getting a dry scalp. You could also buy products that are hypoallergenic if you have sensitive skin. Chlorine is known to dry out skin and hair. If you spend a lot of time in the pool, that could lead to a dry scalp. Fortunately, you don't need to skip swimming altogether; you just need to protect yourself. Rub a conditioning cream into your scalp and hair, and then tuck your hair up into a swimming cap before you go swimming. You might also consider purchasing a shower filter. These will filter out chlorine along with other chemicals that might be in the water. Hot water can be harsh on your skin, scalp, and hair, drying it out. To keep your scalp from drying out too much, turn the heat down when you get in the shower. Try warm showers instead of hot, and stay out of the hot tub. Whether it's winter or summer, weather can wreak havoc on your scalp and hair. In the winter, put a hat on to protect your head from the dry, cold air. In the summer, use sprays that have sunscreen in them to protect your scalp, particularly if you're going to be out in the sun. If you live in a particularly dry or cold climate, the inside of your house likely gets dry during certain parts of the year. Dry air dries out your skin, scalp, and hair, making it harder to control things like dry scalp. One way to remedy the situation is to run a humidifier in your house to increase the humidity in the air. Try running one in your bedroom, for instance.

Summary:
Stay hydrated. Eat hair-healthy foods. Skip dyes and perfumes. Avoid chlorine. Stay out of hot water. Protect your scalp from the weather. Run a humidifier.