Rhamani, Eftekhari, Fallahzadeh, Fararouei, and Massoumi (2018) reviewed the effects of vitamin D and omega-3 on bedwetting wetting. This was a randomized, placebo-controlled double-blinded trial of 162 children. They were divided into 4 groups. One group received 1,000 international units of Vitamin D a day, the second group received omega, -3 1000 mg per day, the third group received both Vitamin D and omega-3, and the fourth group received a placebo.
Vitamin D indirectly affects fluid retention by regulating calcium. It is thought that omega 3 fatty acids influence the signaling of the brain, prostaglandin E2, and nitric oxide synthesis.
After 8 weeks, it documents that there is a 44% cure rate in the Vitamin D group. 28% cure rate in the omega-3 group, 45% cure rate in Vitamin D and omega-3 group, and only a 3% cure rate in the placebo group. I could not find what the authors defined as “cured”. They spoke of fewer wet nights per week. The mean wet nights were 5-7 at baseline. There was no follow up after therapy was stopped.
My opinion: Vitamin D supplementation is a reasonable approach for patients not ready to start behavioral therapy. This would also be beneficial for patients that live 37 degrees or more north or south of the equator. The American Academy of Pediatrics recommends that children and adolescents get 600 IU of Vitamin D a day. Ideally, you would find a pediatric multivitamin that included both vitamin D and omega-3. Keep in mind that the FDA does not regulate supplements. Consult your provider on the best kinds for your child.
Rahmani, E., Eftekhari, M., Fallahzadeh, M., Fararouei, M., & Massoumi, S. (2018). Effect of vitamin D and omega-3 on nocturnal enuresis of 7–15-year-old children. Journal of Pediatric Urology, 14(3). doi:10.1016/j.jpurol.2018.01.007