Research from Hartford Hospital suggests that there is a direct relationship between vitamin D and muscle strength.

Want to get stronger as you get older? Add some sunshine and salmon to your strength-training routine. These two vitamin D powerhouses could help you maintain — and even increase — muscle vitality as you age.

That’s what Hartford Hospital researchers concluded after evaluating more than 400 adults in a recent study. Participants with high levels of circulating vitamin D had more arm and leg muscle strength, regardless of age, gender, resting heart rate, blood pressure, body mass index, or maximal oxygen uptake.

“Our study suggests that there is a direct relationship between vitamin D and muscle strength,” says Paul D. Thompson, MD, FACSM, chief of cardiology at the Hartford, Conn., hospital. The findings were published in Medicine & Science in Sports & Exercise, the journal of the American College of Sports Medicine. Thompson says further research is needed to determine whether the method of vitamin D intake (in supplements or food, or made from sunlight) is important and what dosage is especially beneficial for building stronger muscles. But these early findings add one more reason to ask your doctor to check your vitamin D levels.

Everyone can benefit from vitamin D, whether someone is at immediate risk of muscle-mass loss or not, says Thompson. “The group that we’re most concerned about is older individuals, whose loss of muscle strength could result in frailty,” he says, adding that building muscle can improve balance and energy at any age.