How to maintain muscles

Cole Porter’s song, “It’s DeLovely,” is decidedly divergent with its definition of D: “It’s delightful, it’s delicious/It’s delectable, it’s delirious/It’s dilemma, it’s delimit/it’s deluxe/ It’s de-lovely.”

The scientific opinions on the virtues of vitamin D are almost as diverse. On the plus side, high levels of the nutrient are associated with reduction of some cancers, improved immune function and increased bone strength. But, too much can lower blood levels of atorvastatin. And, in some (but not all) studies supplementation with D didn’t reduce cardiovascular risks or help prevent falls in older adults. It also hasn’t proved effective against seasonal affective disorder, upper respiratory infections or mild psoriasis. (Folks ask a lot of this vitamin/ hormone!)

Well, there’s been one more study of D’s powers. This time it’s positive — about its ability to help prevent loss of muscle strength. Researchers analyzed data on around 3,200 folks aged 50 and older. They found that when your body has enough D, it helps repair muscles and aids in releasing calcium for muscle contractions. But, participants who were D-ficient, with blood levels below 30nm/L, had 78% increased risk of muscle weakness and those who were low, but not deficient (blood levels of 30 to 50nmol/L), had a 77% increased risk.

D is clearly important for many bodily functions. So, to get enough: Eat D-fortified foods and salmon and mushrooms; and get a blood test to check serum levels — before you take a supplement. Until that measurement, I recommend around 1,000 IU a day of D3. After — do what your doc recommends.

Health pioneer Michael Roizen, M.D., is chief wellness officer emeritus at the Cleveland Clinic and author of four No. 1 New York Times bestsellers. His next book is “The Great Age Reboot: Cracking the Longevity Code for a Younger Tomorrow.” Do you have a topic Dr. Mike should cover in a future column? If so, please email questions@ GreatAgeReboot.com.