If you’re part of the 1-in-4 North Americans who’s hooked on a tablet-sized digital device such as an e-reader, and you bring it to bed, you’re a lot more likely to have trouble falling asleep than seeing the Browns win two games in a row. That’s because your device might be chasing away your melatonin — the so-called vampire hormone — a sleep-inducing secretion that comes out only in the dark at night.

Melatonin, a product of the pea-size pineal gland located in the center of your brain, is essential for a good night’s sleep and a healthy immune system. Unfortunately, two hours of exposure to a self-luminous electronic display (a back-lit screen) can reduce your body’s melatonin output by up to 22 percent. That’s a formula for midnight raids on the fridge, not to mention all the other health problems that chronic sleep deprivation can trigger: anxiety, depression, elevated inflammation and LDL cholesterol, and susceptibility to infection.

So here’s what we suggest to help you get a good night’s sleep.

Æ No electronic devices for two hours before bedtime.

Æ Make sure all nightlights are red: that wavelength doesn’t shut off melatonin.

Æ Regulate bedroom noise and light. If needed, try a white-noise machine (a fan can do the trick) and use light-blocking shades or curtains for complete darkness.

If the computer was causing your sleepless nights, that should do the trick. And if you still can’t sleep, avoid caffeine after lunchtime, don’t exercise or eat close to bedtime. Z-Z-Z-Z.

The You Docs — Mehmet Oz, host of “The Dr. Oz Show” and Mike Roizen of Cleveland Clinic — are authors of “YOU: Losing Weight.” To submit questions, go to www.RealAge.com. A King Features syndicate.