Q: How important is it to take calcium supplements with meals? I've read that calcium citrate doesn't need to be taken with food but calcium carbonate does. Is this true? — Darlene, Mountville, Pa.
A: Yup, it's true. Calcium is like a baby's diaper: If you don't have good absorption, you'll find yourself in a mess. Food helps your body absorb calcium carbonate better. But you can take calcium citrate on an empty stomach, and it will work fine. Plus, if you have reduced stomach acid — something that happens with age — you're better off with calcium citrate anyway. It's what we take.
You need 1,000 mg of calcium a day (1,200 after 60), but get as much as you can from food. It's pretty easy to get some calcium — a glass of skim milk and calcium-fortified orange juice have 300 mg each — but it's hard to consistently get all you need.
So take a 600 mg supplement plus 1,000 IU of vitamin D3 (to maximize absorption) and 400-500 mg of magnesium (to counter constipation and heart risks from calcium). Tip: Don't wash down calcium pills with milk. If too much calcium hits your small intestine at once, the intestinal wall rebels and allows less of it into your system.
Q: I've been a short sleeper since I was a child. Now, at 57, I rarely sleep more than six hours. If I sleep longer, I feel logy. I fall asleep quickly, and I almost always wake up before my alarm. Are there any health worries from sleeping less than eight hours? — Jane, Bloomington, Ind.
A: Anywhere between six and eight hours is the magic number for most of us, though some people (including Dr. Mike and sometimes Dr. Oz) happily run on less. Sleep studies go on constantly, but often have contradictory results. In one, people who routinely slept seven hours had lower mortality rates than those who slept more than seven hours — or less than seven. Other studies suggest six hours is better. Some interesting research suggests sleeping longer than eight hours a night can be life-shortening — maybe you really can get too much of a good thing.
Scientists also are concerned about sleep habits because there are strong correlations between how long you sleep and your risk for obesity and heart disease.
That said, the answer is as individual and unique as Lady Gaga. If after just six hours in dreamland you're slim and healthy, get your work done, feel fit and can kick up your heels during the day without an IV caffeine drip, don't lose any sleep over it. Instead, enjoy the extra hour or two you get every day.
Q: How can I break a lifelong nail-biting habit? I'm 43, and I've passed my gross habit onto my 3- and 5-year-olds. My doctor laughs at me, but it's embarrassing. I can't help my kids if I can't stop. — Anonymous
A: Biting your nails while watching a scary horror flick (say, the latest "Saw" movie) is pretty normal — it's a tension reliever and can calm and relax you. But nail biting is no laughing matter if you've gnawed yours down to the nail beds or they become infected. Lebron James may get superpower from biting his nails — or so his coach has said — but all you're going to get from your bitten, raggedy nails is appearing like a nervous wreck, even if you're as calm as Lebron on the free-throw line.
We assume you've tried aversion therapy, like putting red pepper on your nails or using bitter stop-biting liquids from the drugstore. Next step: "habit reversal," a psychological technique that's up to 99 percent successful in both adults and children who are fighting habits like compulsive nail biting (impress your kids and call it onychophagia). Working with a shrink, you'll learn relaxation techniques, become aware of what sets off biting binges and learn to avoid these triggers. You'll also work out ways to keep your hands busy: knitting, needlework, a "fidget" toy, stress ball, worry beads — all help, and you easily can pass these on to your children.
The YOU Docs, Mehmet Oz and Mike Roizen, are authors of "YOU: On a Diet." Want more? See "The Dr. Oz Show" at 9 a.m. and 3 p.m. on Ch. 13. To submit questions, go to www.RealAge.com.
© 2010 Michael Roizen, M.D. and Mehmet Oz, M.D.
Dist. by King Features Syndicate Inc.