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Vitamin D supplementation did not ease the muscle symptoms of statin users in the randomized VITAL trial, a substudy showed.

Over 4.8 years of follow-up, 31% of statin users assigned to vitamin D reported muscle pain or discomfort lasting several days, which was the same proportion as those assigned placebo, with 13% of both groups discontinuing their statin because of muscle symptoms, reported Mark Hlatky, MD, of Stanford University School of Medicine in California, and colleagues.

"These null results in a large, contemporary randomized clinical trial suggest that vitamin D has little, if any, association with preventing SAMS [statin-associated muscle symptoms]," they concluded in .

Statins are key preventive medications that remain widely blamed for muscle aches and pains in patients. Observational studies have linked low levels of vitamin D to the development of statin-associated muscle symptoms, with related to altered enzyme activity and the indirect increased toxicity of some statins.

Now, however, the benefits of vitamin D supplementation for muscle symptoms have failed to come to fruition in a more rigorous study. Indeed, strong evidence shows that such complaints actually stem from a nocebo effect due to negative expectations from statin users from the start.

"We had high hopes that vitamin D would be effective because in our clinic and across the country, statin-associated muscle symptoms were a major reason why so many patients stopped taking their statin medication," said study co-author Neil Stone, MD, of Northwestern University Feinberg School of Medicine in Chicago, in a press release.

"So, it was very disappointing that vitamin D failed a rigorous test. Nevertheless, it's important to avoid using ineffective treatments and instead focus on research that can provide an answer," he added.

Stone suggested that in clinical practice any perceived statin intolerance should be investigated by analyzing other medications used by patients, determining whether patients have associated metabolic or inflammatory conditions, counseling patients on hydrating adequately, and discussing pill anxiety.

VITAL was a 2×2 factorial, double-blind trial in which participating men and women were free of cancer and cardiovascular disease at baseline.

Hlatky and colleagues conducted a substudy on participants who reported initiating statin therapy after randomization to daily cholecalciferol (n=1,033) or placebo (n=1,050). Mean age was 66.8 years, and women comprised approximately half of the cohort.

The response rate to the study's survey about statin-associated muscle symptoms was high, at 88%.

Vitamin D's null results were consistent across pretreatment 25-hydroxy vitamin D levels. Among patients with levels less than 20 ng/mL, muscle symptoms were reported by 33% of the vitamin D group and 35% of those assigned placebo; for those with levels less than 30 ng/mL, muscle symptoms were reported by 27% and 30%, respectively.

Hlatky and team acknowledged that statin therapy was initiated after randomization in the trial, at the discretion of the participants' personal physicians, and that statin-associated muscle symptoms had not been not evaluated or treated prospectively.

The main finding of VITAL was that neither vitamin D nor omega-3 fatty acid supplementation prevented in women 55 and older and men 50 and older. Subsequent VITAL analyses have also shown vitamin D to be of no help for preventing bone fractures or frailty, though there was a signal that the tested supplements were associated with reductions in autoimmune disease.

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