A new study says that taking vitamin D supplements for bone-strengthening and protection against osteoporosis is not necessary for healthy middle-aged adults.

But a bone health expert at Cleveland Clinic urges people at risk for vitamin D deficiency to consult their doctors before discontinuing use.

Studies showed no significant increase in BMD

Recent concerns about the safety risks of taking calcium supplements has led some adults to take vitamin D (without calcium) for bone protection.

The University of Auckland study — a meta-analysis of past studies — found that vitamin D supplements alone had little effect on bone-mineral density (BMD). Investigators combined data from 23 past trials, studying 4082 adults, 92 percent of whom were women. Studies showed no significant increase in BMD in most areas of the body.

In light of this researchers concluded that widespread use of vitamin D for osteoporosis prevention in adults without risk factors for vitamin D deficiency was unwarranted.

Importance of vitamin D shouldn’t be minimized

Chad Deal, MD, was not involved in the study but is Director of the Center of Osteoporosis and Metabolic Bone Disease at Cleveland Clinic.

Though not disagreeing with the study’s conclusions, he worries that the findings may cause some to minimize the positive impact of vitamin D on at-risk people.

“The study is on the effect of vitamin D on BMD, which is modest and not surprising,” says Dr. Deal. “Vitamin D would not be expected to have a large effect unless the patient had severe vitamin D deficiency, in which case the bone density effect could be significant.”

“Patients with vitamin D deficiency should not get the take-home message that vitamin D will not benefit them,” he says.

Fracture protection and other safeguards

For older, at-risk patients, vitamin D deficiency can have a major impact on fracture, says Dr. Deal. Deficiency can cause osteomalacia, softening of the bone due to impaired mineralization, which makes fractures more likely.

“Bone mineral density is not a perfect surrogate for fracture, especially in older patients,” Dr. Deal says.

Vitamin D can also have “huge benefits” on muscle function, cognition and falling, he adds.

Healthy middle-aged adults should talk to their doctor about both their vitamin D and calcium levels to see if they need to be taking vitamin D supplements, either alone or with calcium.