Researchers have revealed that taking vitamin D and calcium twice a day may reduce your chances of getting vertigo again - a sudden internal or external spinning sensation, often triggered by moving your head too quickly."Our study suggests that for people with benign paroxysmal positional vertigo, taking a supplement of vitamin D and calcium is a simple, low-risk way to prevent vertigo from recurring," said study researcher Ji-Soo Kim from Seoul National University in South Korea."It is especially effective if you have low vitamin D levels to begin with," Kim wrote in a paper published in the journal Neurology.Benign paroxysmal positional vertigo happens when a change in head position gives you a sudden spinning sensation. It's one of the most common types of vertigo.About 86 people of people with this form of vertigo find that it interrupts their daily life or causes them to miss days at work.The study looked at 957 people in Korea with benign paroxysmal positional vertigo who were treated successfully with the head movements. The participants were separated into two groups, intervention and observation.The 445 people in the intervention group had their vitamin D levels taken at the start of the study. The 348 people with vitamin D levels below 20 nanograms per millilitre (ng/mL) were started on supplements with 400 international units of vitamin D and 500 milligrams of calcium twice daily, while those with vitamin D levels equal to or greater than 20 ng/mL were not given supplements.According to the study, 512 people in the observation group did not have their vitamin D levels monitored and they did not get supplements.Those in the intervention group who took the supplements had a lower recurrence rate for vertigo episodes after an average of one year than those in the observation group. People taking supplements had an average recurrence rate of 0.83 times per person-year, compared to 1.10 times per person-year for those in the observation group, or a 24 per cent reduction in the annual recurrence rate.There appeared to be a greater benefit for those who were more deficient in vitamin D at the start of the study."Our study suggests an inexpensive, low-risk treatment like vitamin D and calcium tablets may be effective at preventing this common, and commonly recurring, disorder," Kim noted.