Ilkka Laaksi 2010

Vitamin D Supplementation for the Prevention of Acute Respiratory Tract Infection: A Randomized, Double-Blinded Trial among Young Finnish Men

 * Ilkka Laaksi, Juha-Petri Ruohola, Ville Mattila, Anssi Auvinen, Timo Ylikomi, Harri Pihlajamäki
 * The Journal of Infectious Diseases, Volume 202, Issue 5, 1 September 2010, Pages 809–814,
 * https://doi.org/10.1086/654881
 * https://academic.oup.com/jid/article/202/5/809/1746565
 * Published:01 September 2010

Already 10 years ago the benefit of 10ug (400IU) was detectable in a group of young basically fit conscripts with a decent median baseline Vitamin-D serum status of 76nmol/l (30.4ng/ml) falling to 72nmol/l (28.8ng/ml) with supplementation (controls fell to 51nmol/l = 20.4ng/ml) during winter.

So basically from a good start and receiving 10ug (400IU) + 7ug (280IU) = 17ug (680IU) compared to controls from the same start receiving almost half as much (41%) of the small amount from food 7ug (280IU) we STILL see a benefit against respiratory infections in a small study of n=164 of just 6 months (one winter season).

Imagine a study in a country with gross deficiency and 100-200ug (4000-8000IU). Imagine if someone with a brain saw this and simply said let us increase the recommended dose until people no longer have a falling serum level from their summer high.

"The present placebo-controlled double-blinded study involving 164 young Finnish men provides some evidence for a preventive effect of vitamin D supplementation against respiratory tract infection. The Cox regression analysis indicated that the hazard ratio for absence from duty due to respiratory tract infection was lower in the vitamin D supplementation group than it was in the control group. The number of days absent was slightly lower and the proportion of subjects without any days absent was slightly higher in the vitamin D supplementation group, compared with the control group."