Is it possible that vitamin D supplementation could reduce children’s risk of coming down with Influenza A by 58%, and of having an asthma attack by 83%?
Amazing as these claims might seem, this is what was reported in the March 2010 issue of the American Journal of Clinical Nutrition.
The students in this study – which was performed in Japan – ranged in age from 6-15 years of age, and they were given Vitamin D3 (cholecalciferol) at a daily dose of 1200 IU (International Units).
Although these improvements were observed for Influenza A and asthma attacks, there didn’t seem to be any effect on the occurence of Influenza B.
I first ran across this study in a article published in Reuters that was titled ‘Vitamin D helps fend off flu, asthma attacks: study’.
You can see a copy of it at this web address – http://www.reuters.com/article/idUSTRE62I3MK20100319 , and you can find a copy of the article they’re referencing at this web address – http://www.ajcn.org/content/91/5/1255.abstract?sid=39de4a22-ae42-40ad-82b8-77cc9f352efd .
If you want to read it you’ll have to buy a copy from the journal, but I’ve posted an excerpt from their abstract here for your review:
Results: Influenza A occurred in 18 of 167 (10.8%) children in the vitamin D3 group compared with 31 of 167 (18.6%) children in the placebo group [relative risk (RR), 0.58; 95% CI: 0.34, 0.99; P = 0.04]. The reduction in influenza A was more prominent in children who had not been taking other vitamin D supplements (RR: 0.36; 95% CI: 0.17, 0.79; P = 0.006) and who started nursery school after age 3 y (RR: 0.36; 95% CI: 0.17, 0.78; P = 0.005). In children with a previous diagnosis of asthma, asthma attacks as a secondary outcome occurred in 2 children receiving vitamin D3 compared with 12 children receiving placebo (RR: 0.17; 95% CI: 0.04, 0.73; P = 0.006).
Conclusion: This study suggests that vitamin D3 supplementation during the winter may reduce the incidence of influenza A, especially in specific subgroups of schoolchildren. This trial was registered at https://center.umin.ac.jp as UMIN000001373.
The reference for the article is:
Mitsuyoshi Urashima, Takaaki Segawa, Minoru Okazaki, Mana Kurihara, Yasuyuki Wada, and Hiroyuki Ida. Randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren. Am J Clin Nutr May 2010 vol. 91 no. 5 1255-1260.
Two thoughts come to mind. 1. I wonder if the influenza vaccine can match these results for Influenza A?, and 2. I suppose it should improve adults odds also.
So, I’m going to keep on taking my 2000 IU of Vitamin D3 every day. Just in case.
Remember, I’m a pharmacist – not a doctor. Check with your doctor before changing your medication regimens or adding any supplements to your daily routine.
Doctors Doctor. Pharmacists Pharmacist. That’s how it’s supposed to be.