In the study, called the Finnish Vitamin D Trial (FIND), conducted at the University of Eastern Finland between 2012 and 2018, 2,495 participants were randomized to receive either placebo, 1,600 IU/day of vitamin D3 and 3,200 IU/day of vitamin D3.
A recent longitudinal study1 found that long-term vitamin D supplementation may reduce the risk of atrial fibrillation (AF). In the study, called the Finnish Vitamin D Trial (FIND), conducted at the University of Eastern Finland between 2012 and 2018, 2,495 participants were randomized to receive either placebo, 1,600 IU/day of vitamin D3 and 3,200 IU/day of vitamin D3. Participants completed questionnaires at baseline, 12 months, 24 months, 36 months, and at the end of the trial (60 months). Serum vitamin D3 concentration was measured using high-performance liquid chromatography from samples collected at baseline, 6 months, and 12 months.
After excluding 122 subjects who reported taking antiarrhythmic medications at baseline, results showed that subjects taking 1,600 IU/day of vitamin D3 saw a 27% lower risk of AF diagnosis, while those taking 3,200 IU/day of vitamin D3 saw a non-significant 30% lower risk. While other studies have found that vitamin D deficiency is associated with higher risk of AF diagnosis, according to the researchers, this is the first randomized controlled trial that observed a reduced risk of AF following vitamin D supplementation.
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