Respiratory Virus risk reduced 35 percent by Vitamin D (14,000 IU weekly) – RCT

Effect of Vitamin D supplementation to reduce respiratory infections in children and adolescents in Vietnam: a randomized controlled trial.

Influenza Other Respir Viruses. 2018 Oct 16. doi: 10.1111/irv.12615. [Epub ahead of print]

Loeb M1 [email protected] , Dang AD2, Thiem VD3, Thanabalan V4, Wang B4, Nguyen NB5, Tran HTM2, Luong TM2, Singh P4, Smieja M4, Maguire J6, Pullenayegum E7.

Comments on the study by Vitamin D Life1. They appeared to start counting the infections immediately after starting the vitamin D, rather than waiting 4-6 months for the blood levels to plateau1. Virtually all of the children had a high level of vitamin D to start with, so raising it even more should not be expected to result in a large benefit1. They used the amount of Vitamin D independent of age/weight* Suspect that at least 2800 IU Vitamin D would be needed for the older/heavier children* * *Suspect > 50% reduction if had used more Vitamin D (to get most about 40 ng), had started before flu season, had used dose size was proportional to weight, children did not have such a high level to start with---* Half the risk of Influenza -A in infants taking 1200 IU of vitamin D for 4 months – RCT Jan 2018* Overview Influenza and vitamin D* Respiratory infections reduced by 63 percent with 4000 IU vitamin D daily - RCT Dec 2012* 7X less risk of influenza if Vitamin D levels higher than 30 ng – Oct 2017* Influenza prevented by 40 ng levels or treated with vitamin D hammer (50,000 IU) – June 2015* Reduced viral respiratory track infections by half by having more than 38 ng of vitamin D – June 2010* Group with >38 ng of vitamin D was 2X less likely to get viral infection*** --- 1. Breathing category starts with the following{include}---All of the studies in Breathing and Virus are listed here: {category}

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BACKGROUND: It is uncertain whether Vitamin D can reduce respiratory infection.

OBJECTIVE: To determine if vitamin D supplementation reduces influenza and other upper viral respiratory tract infections.

METHODS:

1,300 healthy children and adolescents between the ages of 3 and 17 years were randomized to vitamin D (14,000U weekly) or placebo for eight months in Vietnam. The primary outcome was reverse transcriptase (RT) -PCR confirmed influenza infection and the co-primary outcome was multiplex PCR confirmed non-influenza respiratory viruses. Participants, care givers, and those assessing outcomes were blinded to group assignment.

RESULTS:

650 children and adolescents were randomly assigned to vitamin D and 650 to placebo. The mean baseline serum 25-hydroxyvitamin D levels were 65.7 nmol/L and 65.2 nmol/L in the intervention and placebo groups respectively, with an increase to 91.8 nmol/L in the vitamin D group and no increase, 64.5 nmol/L, in the placebo group. All 1,300 participants randomized contributed to the analysis.

We observed RT-PCR confirmed influenza A or B occurred in 50 children (7.7%) in the vitamin D group and in 43 (6.6%) in the placebo group (hazard ratio [HR] 1.18, 95%CI 0.79 to 1.78). RT-PCR confirmed non-influenza respiratory virus infection occurred in 146 (22.5%) in the vitamin D group and in 185 (28.5%) in the placebo group (hazard ratio [HR] 0.76, 95% CI 0.61 to 0.94). When considering all respiratory viruses, including influenza, the effect of vitamin D in reducing infection was significant, HR 0.81, 95% CI 0.66 to 0.99.

CONCLUSION: Vitamin D supplementation did not reduce the incidence of influenza but moderately reduced non-influenza respiratory viral infection.

Snips from PDF

• “One possible limitation was the use of oropharyngeal specimens instead of nasopharyneal specimens. This was based on adherence to testing and we reasoned that an increase in the number of swabs would make up for any reduction in sensitivity.”

• “Only 17% of participants in our study had vitamin D levels < 50 nmol/L, in contrast to a previous study from Vietnam where > 50% children had insufficiency or deficiency (23). The relatively high vitamin D levels in our study may have reduced the effectiveness of vitamin D supplementation in preventing influenza. “

  Non-influenza virus infection