The multi-center study included 957 people in South Korea with benign paroxysmal positional vertigo who had undergone canalith repositioning maneuvers—head movements that shift displaced calcium carbonate crystals in the inner ear. The intervention group included patients who received 400 IU vitamin D and 500 mg calcium carbonate twice daily for 1 year when their baseline serum vitamin D level was below 20 ng/mL along with patients who had higher baseline levels and took no supplements. An observation group had no baseline testing or interventions.

The supplements significantly reduced the annual vertigo recurrence rate by 24%. There were 0.83 recurrences per 1 person-year in the intervention group compared with 1.10 in the observation group. Patients with greater vitamin D deficiencies at baseline derived the most benefit.

JAMA. 2020;324(16):1599. doi:10.1001/jama.2020.18695 — https://jamanetwork.com/journals/jama/fullarticle/2772275

BPPV = benign paroxysmal positional vertigo. The original study in Neurology and the JAMA summary both use the word “prevent” in their respective titles. I think reduce is a more apt description. Semantics aside a 24% reduction in recurrent BPPV episodes is significant.

And yet another example of nutritional deficiencies underlying another disease.